This patch removes the storming threashold enlarging quirk.
After applying the following commit, we can notice that there is no no-op
GPE handling invocation can be observed, thus it is unlikely that the
no-op counts can exceed the storming threashold:
Commit: ca37bfdfbc
Subject: ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
Even when the storming happens, we have already limited its affection to
the only transaction and no further transactions will be affected. This is
done by this commit:
Commit: e1d4d90fc0
Subject: ACPI / EC: Refine command storm prevention support
So it's time to remove this quirk.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=45151
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch updates acpi_ec_is_gpe_raised() according to the following
commit:
Commit: 09af8e8290
Subject: ACPICA: Events: Add support to return both enable/status register values for GPE and fixed event.
This is actually a no-op change as both the flags are defined to a same
value.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use list_for_each_entry_safe for iterating because handler may be freed
in the loop.
BUG: unable to handle kernel NULL pointer dereference at 000000000000002c
IP: [<ffffffff814d69c8>] acpi_ec_put_query_handler+0x7/0x1a
Call Trace:
acpi_ec_remove_query_handler+0x87/0x97
acpi_smbus_hc_remove+0x2a/0x44 [sbshc]
acpi_device_remove+0x7b/0x9a
__device_release_driver+0x7e/0x110
driver_detach+0xb0/0xc0
bus_remove_driver+0x54/0xe0
driver_unregister+0x2b/0x60
acpi_bus_unregister_driver+0x10/0x12
acpi_smb_hc_driver_exit+0x10/0x12 [sbshc]
SyS_delete_module+0x1b8/0x210
system_call_fastpath+0x12/0x6a
Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
On some machines(E,G Mircosoft surface 3), ACPI battery depends on
the EC operation region and it has _DEP method which contains EC.
Current code doesn't support such devices whose dep_unmet will be
not be decreased after EC opregion handler being installed. This
blocks battery device to be attached with its driver. This patch
is to fix the issue.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=90161
Reported-and-tested-by: Lompik <lompik@voila.fr>
Tested-by: Valentin Lab <valentin.lab_bugzilla.kernel.org@kalysto.org>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch enhances debugging with the GPE reference count messages added.
This kind of log entries can be used by the platform validators to validate
if there is an EC transaction broken because of firmware/driver bugs.
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch refines logging/debugging splitter support so that when DEBUG is
disabled, splitters won't be visible in the kernel logs while they are
still available for developers when DEBUG is enabled.
This patch also refines the splitters to mark the following handling
process boundaries:
+++++: boundary of driver starting/stopping
boundary of IRQ storming
=====: boundary of transaction advancement
*****: boundary of EC command
boundary of EC query
#####: boundary of EC _Qxx evaluation
The following 2 log entries are originally logged using pr_info() in order
to be used as the boot/suspend/resume log entries for the EC device, this
patch also restores them to pr_info() logging level:
ACPI : EC: EC started
ACPI : EC: EC stopped
In this patch, one log entry around "Polling quirk" is converted into
ec_dbg_raw() which doesn't contain the boundary marker.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove unusual pr_info() visual emphasis introduced in ad479e7f47
"ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag".
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
[ rjw: Change pr_info() to pr_debug() too in those places. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit f252cb09e1 (ACPI / EC: Add query flushing support),
because it breaks system suspend on Acer Aspire S5. The machine
just hangs solid at the last stage of suspend (after taking non-boot
CPUs offline).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit b5bca896ef (ACPI / EC: Add GPE reference counting
debugging messages), because it depends on commit f252cb09e1
(ACPI / EC: Add query flushing support) which breaks system suspend
on Acer Aspire S5 and needs to be reverted.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch enhances debugging with the GPE reference count messages added.
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implementes the QR_EC flushing support.
Grace periods are implemented from the detection of an SCI_EVT to the
submission/completion of the QR_EC transaction. During this period, all
EC command transactions are allowed to be submitted.
Note that query periods and event periods are intentionally distiguished to
allow further improvements.
1. Query period: from the detection of an SCI_EVT to the sumission of the
QR_EC command. This period is used for storming prevention, as currently
QR_EC is deferred to a work queue rather than directly issued from the
IRQ context even there is no other transactions pending, so malicous
SCI_EVT GPE can act like "level triggered" to trigger a GPE storm. We
need to be prepared for this. And in the future, we may change it to be
a part of the advance_transaction() where we will try QR_EC submission
in appropriate positions to avoid such GPE storming.
2. Event period: from the detection of an SCI_EVT to the completion of the
QR_EC command. We may extend it to the completion of _Qxx evaluation.
This is actually a grace period for event flushing, but we only flush
queries due to the reason stated in known issue 1. That's also why we
use EC_FLAGS_EVENT_xxx. During this period, QR_EC transactions need to
pass the flushable submission check.
In this patch, the following flags are implemented:
1. EC_FLAGS_EVENT_ENABLED: this is derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT handlings.
With this flag, the logics implemented by the original flag are
extended:
1. Old logic: unless both of the flags are set, the event poller will
not be scheduled, and
2. New logic: as soon as both of the flags are set, the evet poller will
be scheduled.
2. EC_FLAGS_EVENT_DETECTED: this is also derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT detection. It thus
can be used to indicate the storming prevention period for query
submission.
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that acpi_set_gpe() can be invoked under the
"reference count > 0" condition.
3. EC_FLAGS_EVENT_PENDING: this is newly added to indicate the grace period
for event flushing (query flushing for now).
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that the flushing process can wait until the
event handling (query transaction for now) to be completed.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch refines EC command storm prevention support.
Current command storming code is wrong, when the storming condition is
detected, it only flags the condition without doing anything for the
current command but performing storming prevention for the follow-up
commands. So:
1. The first command which suffers from the storming still suffers from
storming.
2. The follow-up commands which may not suffer from the storming are
unconditionally forced into the storming prevention mode.
Ideally, we should only enable storm prevention immediately after detection
for the current command so that the next command can try the
power/performance efficient interrupt mode again.
This patch improves the command storm prevention by disabling GPE right
after the detection and re-enabling it right before completing the command
transaction using the GPE storming prevention APIs. This thus deploys the
following GPE handling model:
1. acpi_enable_gpe()/acpi_disable_gpe() for reference count changes:
This set of APIs are used for EC usage reference counting.
2. acpi_set_gpe(ACPI_GPE_ENABLE)/acpi_set_gpe(ACPI_GPE_DISABLE):
This set of APIs are used for preventing GPE storm. They must be invoked
when the reference count > 0.
Note that as the storming prevention should always happen when there is
an outstanding request, or GPE enabling value will be messed up by the
races. This patch also adds BUG_ON() to enforces this rule to prevent
future bugs.
The msleep(1) used after completing a transaction is useless now as this
sounds like a guard time only useful for platforms that need the
EC_FLAGS_MSI quirks while we have fixed GPE race issues using the previous
raw handler mode enabling. It is kept to avoid regressions. A seperate
patch which deletes EC_FLAGS_MSI quirks should take care of deleting it.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implements the EC command flushing support.
During the grace period indicated by EC_FLAGS_STARTED and EC_FLAGS_STOPPED,
all submitted EC command transactions can be completed and new submissions
are prevented before suspending so that the EC hardware can be ensured to
be in the idle state when the system is resumed.
There is a good indicator for flush support:
All acpi_ec_submit_request() is invoked after checking driver state with
acpi_ec_started() except the first one. This means all code paths can be
flushed as fast as possible by discarding the requests occurred after the
flush operation. The reference increased for such kind of code path is
wrapped by acpi_ec_submit_flushable_request().
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
By using the 2 flags, we can indicate an inter-mediate state where the
current transactions should be completed while the new transactions should
be dropped.
The comparison of the old flag and the new flags:
Old New
about to set BLOCKED STOPPED set / STARTED set
BLOCKED set STOPPED clear / STARTED clear
BLOCKED clear STOPPED clear / STARTED set
A new period can be indicated by the 2 flags. The new period is between the
point where we are about to set BLOCKED and the point when the BLOCKED is
set. The new flags facilitate us with acpi_ec_started() check to allow the
EC transaction to be submitted during the new period. This period thus can
be used as a grace period for the EC transaction flushing.
The only functional change after applying this patch is:
1. The GPE enabling/disabling is protected by the EC specific lock. We can
do this because of recent ACPICA GPE API enhancement. This is reasonable
as the GPE disabling/enabling state should only be determined by the EC
driver's state machine which is protected by the EC spinlock.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The bug fixes around GPE races have been done to the EC driver by the
previous commits. This patch increases the revision to 3 to indicate the
behavior differences between the old and the new drivers. The
copyright/authorship notices are also updated.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Timeout in the ec_poll() doesn't refer to the last register access time. It
thus can win the competition against the acpi_ec_gpe_handler() if a
transaction takes longer than 1ms but individual register accesses are less
than 1ms. In some cases, it can make the following silicon bug easier to
be triggered:
GPE EN is not wired to the GPE trigger line, so when GPE STS is already
set when 1 is written to GPE EN, no GPE can be triggered.
This patch adds register access timestamp reference support for ec_poll()
to reduce the number of ec_poll() invocations.
Reported-by: Venkat Raghavulu <venkat.raghavulu@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch switches EC driver into ACPI_GPE_DISPATCH_RAW_HANDLER mode where
the GPE lock is not held for acpi_ec_gpe_handler() and the ACPICA internal
GPE enabling/disabling/clearing operations are bypassed so that further
improvements are possible with the GPE APIs.
There are 2 strong reasons for deploying raw GPE handler mode in the EC
driver:
1. Some hardware logics can control their interrupts via their own
registers, so their interrupts can be disabled/enabled/acknowledged
without using the super IRQ controller provided functions. While there
is no mean (EC commands) for the EC driver to achieve this.
2. During suspending, the EC driver is still working for a while to
complete the platform firmware provided functionailities using ec_poll()
after all GPEs are disabled (see acpi_ec_block_transactions()), which
means the EC driver will drive the EC GPE out of the GPE core's control.
Without deploying the raw GPE handler mode, we can see many races between
the EC driver and the GPE core due to the above restrictions:
1. There is a race condition due to ACPICA internal GPE
disabling/clearing/enabling logics in acpi_ev_gpe_dispatch():
Orignally EC GPE is disabled (EN=0), cleared (STS=0) before invoking a
GPE handler and re-enabled (EN=1) after invoking a GPE handler in
acpi_ev_gpe_dispatch(). When re-enabling appears, GPE may be flagged
(STS=1).
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_dispatch() ec_poll()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
EN=1
This race condition is the root cause of different issues on different
silicon variations.
A. Silicon variation A:
On some platforms, GPE will be triggered due to "writing 1 to EN when
STS=1". This is because both EN and STS lines are wired to the GPE
trigger line.
1. Issue 1:
We can see no-op acpi_ec_gpe_handler() invoked on such platforms.
This is because:
a. event pending B: An event can arrive after ACPICA's GPE
clearing performed in acpi_ev_gpe_dispatch(), this event may
fail to be detected by EC_SC read that is performed before its
arrival;
b. event handling B: The event can be handled in ec_poll() because
EC lock is released after acpi_ec_gpe_handler() invocation;
c. There is no code in ec_poll() to clear STS but the GPE can
still be triggered by the EN=1 write performed in
acpi_ev_finish_gpe(), this leads to a no-op EC GPE handler
invocation;
d. As no-op GPE handler invocations are counted by the EC driver
to trigger the command storming conditions, the wrong no-op
GPE handler invocations thus can easily trigger wrong command
storming conditions.
Note 1:
If we removed GPE disabling/enabling code from
acpi_ev_gpe_dispatch(), we could still see no-op GPE handlers
triggered by the event arriving after the GPE clearing and before
the GPE handling on both silicon variation A and B. This can only
occur if the CPU is very slow (timing slice between STS=0 write
and EC_SC read should be short enough before hardware sets another
GPE indication). Thus this is very rare and is not what we need to
fix.
B. Silicon variation B:
On other platforms, GPE may not be triggered due to "writing 1 to EN
when STS=1". This is because only STS line is wired to the GPE
trigger line.
2. Issue 2:
We can see GPE loss on such platforms. This is because:
a. event pending B vs. event handling A: An event can arrive after
ACPICA's GPE handling performed in acpi_ev_gpe_dispatch(), or
event pending C vs. event handling B: An event can arrive after
Linux's GPE handling performed in ec_poll(),
these events may fail to be detected by EC_SC read that is
performed before their arrival;
b. The GPE cannot be triggered by EN=1 write performed in
acpi_ev_finish_gpe();
c. If no polling mechanism is implemented in the driver for the
pending event (for example, SCI_EVT), this event is lost due to
no GPE being triggered.
Note 2:
On most platforms, there might be another rule that GPE may not be
triggered due to "writing 1 to STS when STS=1 and EN=1".
Then on silicon variation B, an even worse case is if the issue 2
event loss happens, further events may never trigger GPE again on
such platforms due to being blocked by the current STS=1. Unless
someone clears STS, all events have to be polled.
2. There is a race condition due to lacking in GPE status checking in EC
driver:
Originally, GPE status is checked in ACPICA core but not checked in
the GPE handler. Thus since the status checking and handling is not
locked, it can be interrupted by another handling path.
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_detect() ec_poll()
if (EN==1 && STS==1)
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
EC_SC handled
Unlock(EC)
*****************************************************************
acpi_ev_gpe_dispatch()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
EC_SC read
Unlock(EC)
*****************************************************************
3. Issue 3:
We can see no-op acpi_ec_gpe_handler() invoked on both silicon
variation A and B. This is because:
a. event pending A: An event can arrive to trigger an EC GPE and
ACPICA checks it and is about to invoke the EC GPE handler;
b. event handling A: The event can be handled in ec_poll() because
EC lock is not held after the GPE status checking;
c. event handling B: Then when the EC GPE handler is invoked, it
becomes a no-op GPE handler invocation.
d. As no-op GPE handler invocations are counted by the EC driver
to trigger the command storming conditions, the wrong no-op
GPE handler invocations thus can easily trigger wrong command
storming conditions.
Note 3:
This no-op GPE handler invocation is rare because the time between
the IRQ arrival and the acpi_ec_gpe_handler() invocation is less than
the timeout value waited in ec_poll(). So most of the no-op GPE
handler invocations are caused by the reason described in issue 1.
3. There is a race condition due to ACPICA internal GPE clearing logic in
acpi_enable_gpe():
During runtime, acpi_enable_gpe() can be invoked by the EC storming
prevention code. When it is invoked, GPE may be flagged (STS=1).
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_dispatch() acpi_ec_transaction()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
EC_SC handled
Unlock(EC)
*****************************************************************
EN=1 ?
Lock(EC)
Unlock(EC)
=================================================================
(event pending B)
=================================================================
acpi_enable_gpe()
STS=0
EN=1
4. Issue 4:
We can see GPE loss on both silicon variation A and B platforms.
This is because:
a. event pending B: An event can arrive right before ACPICA's GPE
clearing performed in acpi_enable_gpe();
b. If the GPE is cleared when GPE is disabled, then EN=1 write in
acpi_enable_gpe() cannot trigger this GPE;
c. If no polling mechanism is implemented in the driver for this
event (for example, SCI_EVT), this event is lost due to no GPE
being triggered.
Note 4:
Currently we don't have this issue, but after we switch the EC
driver into ACPI_GPE_DISPATCH_RAW_HANDLER mode, we need to take care
of handling this because the EN=1 write in acpi_ev_gpe_dispatch()
will be abandoned.
There might be more race issues for the current GPE handler usages. This is
because the EC IRQ's enabling/disabling/checking/clearing/handling
operations should be locked by a single lock that is under the EC driver's
control to achieve the serialization. Which means we need to invoke GPE
APIs with EC driver's lock held and all ACPICA internal GPE operations
related to the GPE handler should be abandoned. Invoking GPE APIs inside of
the EC driver lock and bypassing ACPICA internal GPE operations requires
the ACPI_GPE_DISPATCH_RAW_HANDLER mode where the same lock used by the APIs
are released prior than invoking the handlers. Otherwise, we can see dead
locks due to circular locking dependencies (see Reference below).
This patch then switches the EC driver into the
ACPI_GPE_DISPATCH_RAW_HANDLER mode so that it can perform correct GPE
operations using the GPE APIs:
1. Bypasses EN modifications performed in acpi_ev_gpe_dispatch() by
using acpi_install_gpe_raw_handler() and invoking all GPE APIs with EC
spin lock held. This can fix issue 1 as it makes a non frequent GPE
enabling/disabling environment.
2. Bypasses STS clearing performed in acpi_enable_gpe() by replacing
acpi_enable_gpe()/acpi_disable_gpe() with acpi_set_gpe(). This can fix
issue 4. And this can also help to fix issue 1 as it makes a no sudden
GPE clearing environment when GPE is frequently enabled/disabled.
3. Ensures STS acknowledged before handling by invoking acpi_clear_gpe()
in advance_transaction(). This can finally fix issue 1 even in a
frequent GPE enabling/disabling environment. And this can also finally
fix issue 3 when issue 2 is fixed.
Note 3:
GPE clearing is edge triggered W1C, which means we can clear it right
before handling it. Since all EC GPE indications are handled in
advance_transaction() by previous commits, we can now move GPE clearing
into it to implement the correct GPE clearing.
Note 4:
We can use acpi_set_gpe() which is not shared GPE safer instead of
acpi_enable_gpe()/acpi_disable_gpe() because EC GPE is not shared by
other hardware, which is mentioned in the ACPI specification 5.0, 12.6
Interrupt Model: "OSPM driver treats this as an edge event (the EC SCI
cannot be shared)". So we can stop using shared GPE safer APIs
acpi_enable_gpe()/acpi_disable_gpe() in the EC driver. Otherwise
cleanups need to be made in acpi_ev_enable_gpe() to bypass the GPE
clearing logic before keeping acpi_enable_gpe().
This patch also invokes advance_transaction() when GPE is re-enabled in the
task context which:
1. Ensures EN=1 can trigger GPE by checking and handling EC status register
right after EN=1 writes. This can fix issue 2.
After applying this patch, without frequent GPE enablings considered:
=================================================================
(event pending A)
=================================================================
acpi_ec_gpe_handler() ec_poll()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
The event pending for issue 1 (event pending B) can arrive as a next GPE
due to the previous IRQ context STS=0 write. And if it is handled by
ec_poll() (event handling B), as it is also acknowledged by ec_poll(), the
event pending for issue 2 (event pending C) can properly arrive as a next
GPE after the task context STS=0 write. So no GPE will be lost and never
triggered due to GPE clearing performed in the wrong position. And since
all GPE handling is performed after a locked GPE status checking, we can
hardly see no-op GPE handler invocations due to issue 1 and 3. We may still
see no-op GPE handler invocations due to "Note 1", but as it is inevitable,
it needn't be fixed.
After applying this patch, with frequent GPE enablings considered:
=================================================================
(event pending A)
=================================================================
acpi_ec_gpe_handler() acpi_ec_transaction()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
EN=1
if STS==1
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
The event pending for issue 2 can be manually handled by
advance_transaction(). And after the STS=0 write performed in the manual
triggered advance_transaction(), GPE can always arrive. So no GPE will be
lost due to frequent GPE disabling/enabling performed in the driver like
issue 4.
Note 5:
It's ideally when EN=1 write occurred, an IRQ thread should be woken up to
handle the GPE when the GPE was raised. But this requires the IRQ thread to
contain the poller code for all EC GPE indications, while currently some of
the indications are handled in the user tasks. It then is very hard for the
code to determine whether a user task should be invoked or the poller work
item should be scheduled. So we have to invoke advance_transaction()
directly now and it leaves us such a restriction for the GPE re-enabling:
it must be performed in the task context to avoid starving the GPEs.
As a conclusion: we can see the EC GPE is always handled in serial after
deploying the raw GPE handler mode:
Lock(EC)
if (STS==1)
STS=0
EC_SC read
EC_SC handled
Unlock(EC)
The EC driver specific lock is responsible to make the EC GPE handling
processes serialized so that EC can handle its GPE from both IRQ and task
contexts and the next IRQ can be ensured to arrive after this process.
Note 6:
We have many EC_FLAGS_MSI qurik users in the current driver. They all seem
to be suffering from unexpected GPE triggering source lost. And they are
false root caused to a timing issue. Since EC communication protocol has
already flow control defined, timing shouldn't be the root cause, while
this fix might be fixing the root cause of the old bugs.
Link: https://lkml.org/lkml/2014/11/4/974
Link: https://lkml.org/lkml/2014/11/18/316
Link: https://www.spinics.net/lists/linux-acpi/msg54340.html
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The QR_EC related code pieces have redundants, this patch merges them into
acpi_ec_query() which invokes acpi_ec_transaction() where EC mutex and the
global lock are already held. After doing so, query handler traversal still
need to be locked by EC mutex after invoking acpi_ec_transaction().
Note that EC event handling is sequential. We fetch one event from firmware
event queue and process it until 0x00 or error returned. So we don't need
to hold mutex for whole acpi_ec_clear() process to determine whether we
should continue to drain. And for the same reason, we don't need to hold
mutex for the whole procedure from the QR_EC transaction to the query
handler traversal.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch fixes 2 issues related to the draining behavior. But it doesn't
implement the draining support, it only cleans up code so that further
draining support is possible.
The draining behavior is expected by some platforms (for example, Samsung)
where SCI_EVT is set only once for a set of events and might be cleared for
the very first QR_EC command issued after SCI_EVT is set. EC firmware on
such platforms will return 0x00 to indicate "no outstanding event". Thus
after seeing an SCI_EVT indication, EC driver need to fetch events until
0x00 returned (see acpi_ec_clear()).
Issue 1 - acpi_ec_submit_query():
It's reported on Samsung laptops that SCI_EVT isn't checked when the
transactions are advanced in ec_poll(), which leads to SCI_EVT triggering
source lost:
If no EC GPE IRQs are arrived after that, EC driver cannot detect this
event and handle it.
See comment 244/247 for kernel bugzilla 44161.
This patch fixes this issue by moving SCI_EVT checks into
advance_transaction(). So that SCI_EVT is checked each time we are going to
handle the EC firmware indications. And this check will happen for both IRQ
context and task context.
Since after doing that, SCI_EVT is also checked after completing a
transaction, ec_check_sci() and ec_check_sci_sync() can be removed.
Issue 2 - acpi_ec_complete_query():
We expect to clear EC_FLAGS_QUERY_PENDING to allow queuing another draining
QR_EC after writing a QR_EC command and before reading the event. After
reading the event, SCI_EVT might be cleared by the firmware, thus it may
not be possible to queue such a draining QR_EC at that time.
But putting the EC_FLAGS_QUERY_PENDING clearing code after
start_transaction() is wrong as there are chances that after
start_transaction(), QR_EC can fail to be sent. If this happens,
EC_FLAG_QUERY_PENDING will be cleared earlier. As a consequence, the
draining QR_EC will also be queued earlier than expected.
This patch also moves this code into advance_transaction() where QR_EC is
just sent (ACPI_EC_COMMAND_POLL flagged) to fix this issue.
Notes:
1. After introducing the 2 SCI_EVT related handlings into
advance_transaction(), a next QR_EC can be queued right after writing
the current QR_EC command and before reading the event. But this still
hasn't implemented the draining behavior as the draining support
requires:
If a previous returned event value isn't 0x00, a draining QR_EC need
to be issued even when SCI_EVT isn't set.
2. In this patch, acpi_os_execute() is also converted into a seperate work
item to avoid invoking kmalloc() in the atomic context. We can do this
because of the previous global lock fix.
3. Originally, EC_FLAGS_EVENT_PENDING is also used to avoid queuing up
multiple work items (created by acpi_os_execute()), this can be covered
by only using a single work item. But this patch still keeps this flag
as there are different usages in the driver initialization steps relying
on this flag.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-by: Kieran Clancy <clancy.kieran@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently QR_EC is queued up on CPU 0 to be safe with SMM because there is
no global lock held for acpi_ec_gpe_query(). As we are about to move QR_EC
to a non CPU 0 bound work queue to avoid invoking kmalloc() in
advance_transaction(), we have to acquire global lock for the new QR_EC
work item to avoid regressions.
Known issue:
1. Global lock for acpi_ec_clear().
This is an existing issue that acpi_ec_clear() which invokes
acpi_ec_sync_query() also suffers from the same issue. But this patch's
target is only the code to invoke acpi_ec_sync_query() in a CPU 0 bound
work queue item, and the acpi_ec_clear() can be automatically fixed by
further patch that merges the redundant code, so it is left unchanged.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The returning value of acpi_os_execute() is erroneously handled as errno.
This patch corrects it by returning EBUSY to indicate the work queue item
creation failure.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch adds reference counting for query handlers in order to eliminate
kmalloc()/kfree() usage.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch moves transaction wakeup code into advance_transaction().
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ec_remove_handlers() is invoked without checking
EC_FLAGS_HANDLERS_INSTALLED, this patch enhances this check to avoid issues
that acpi_disable_gpe() is invoked unexpectedly to reduce the GPE runtime
count. This may happen when the EC handler installation failed on some
platforms.
Reported-by: Venkat Raghavulu <venkat.raghavulu@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is reported that Samsung laptops that need to poll events are broken by
the following commit:
Commit 3afcf2ece4
Subject: ACPI / EC: Add support to disallow QR_EC to be issued when SCI_EVT isn't set
The behaviors of the 2 vendor firmwares are conflict:
1. Acer: OSPM shouldn't issue QR_EC unless SCI_EVT is set, firmware
automatically sets SCI_EVT as long as there is event queued up.
2. Samsung: OSPM should issue QR_EC whatever SCI_EVT is set, firmware
returns 0 when there is no event queued up.
This patch is a quick fix to distinguish the behaviors to make Acer
behavior only effective for Acer EC firmware so that the breakages on
Samsung EC firmware can be avoided.
Fixes: 3afcf2ece4 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
[ rjw : Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is reported that the following commit breaks Samsung hardware:
Commit: 558e4736f2.
Subject: ACPI / EC: Add support to disallow QR_EC to be issued before
completing previous QR_EC
Which means the Samsung behavior conflicts with the Acer behavior.
1. Samsung may behave like:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
Without the above commit, Samsung can work:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
CAN prepare next QR_EC as SCI_EVT=1
read event
[ -event 1 ] SCI_EVT clear
write QR_EC
read event
[ -event 2 ] SCI_EVT clear
With the above commit, Samsung cannot work:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
CANNOT prepare next QR_EC as SCI_EVT=0
2. Acer may behave like:
[ +event 1 ] SCI_EVT set
[ +event 2 ]
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
[ +event 2 ] SCI_EVT set
Without the above commit, Acer cannot work when there is only 1 event:
[ +event 1 ] SCI_EVT set
write QR_EC
can prepared next QR_EC as SCI_EVT=1
read event
[ -event 1 ] SCI_EVT clear
CANNOT write QR_EC as SCI_EVT=0
With the above commit, Acer can work:
[ +event 1 ] SCI_EVT set
[ +event 2 ]
write QR_EC
read event
[ -event 1 ] SCI_EVT set
can prepare next QR_EC because SCI_EVT=0
CAN write QR_EC as SCI_EVT=1
Since Acer can also work with only the following commit applied:
Commit: 3afcf2ece4
Subject: ACPI / EC: Add support to disallow QR_EC to be issued when
SCI_EVT isn't set
commit 558e4736f2 can be reverted.
Fixes: 558e4736f2 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch cleans up the following coding style issues that are detected by
scripts/checkpatch.pl:
ERROR: code indent should use tabs where possible
ERROR: "foo * bar" should be "foo *bar"
WARNING: Missing a blank line after declarations
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
WARNING: void function return statements are not generally useful
WARNING: else is not generally useful after a break or return
WARNING: break is not useful after a goto or return
WARNING: braces {} are not necessary for single statement blocks
WARNING: line over 80 characters
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch refines event/query debugging messages to use a unified format
as commands. Developers can clearly find different processes by checking
different log seperators. No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Developers really don't need to translate EC commands in mind. This patch
adds detailed debugging information for the EC commands.
The address can be found in the follow-up sequential EC_DATA(W) accesses,
thus this patch also removes some of the redundant address information.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently some logs are applied to new transactions, but QR_EC transactions
are not included. This patch merges the code path to make the logs also
applying to the QR_EC transactions.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch adds CPU ID to the context entries' debugging output. no
functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Clevo W350etq's EC will not produce GPE interrupt some time after
booting. The ACPI notify event won't trigger when the issue takes
place. After debugging, adding msi quirk for the machine can fix
the issue. This patch is to add msi quirk for the machine.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Reported-and-tested-by: qbanin@gmail.com
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is platform refusing to respond QR_EC when SCI_EVT isn't set
which is Acer Aspire V5-573G.
By disallowing QR_EC to be issued before the previous one has been
completed we are able to reduce the possibilities to trigger issues on
such platforms.
Note that this fix can only reduce the occurrence rate of this issue, but
this issue may still occur when such a platform doesn't clear SCI_EVT
before or immediately after completing the previous QR_EC transaction.
This patch cannot fix the CLEAR_ON_RESUME quirk which also relies on
the assumption that the platforms are able to respond even when SCI_EVT
isn't set.
But this patch is still useful as it can help to reduce the number of
scheduled QR_EC work items.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Reported-and-tested-by: Alexander Mezin <mezin.alexander@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is a platform refusing to respond QR_EC when SCI_EVT isn't set
(Acer Aspire V5-573G).
Currently, we rely on the behaviour that the EC firmware can respond
something (for example, 0x00 to indicate "no outstanding events") to
QR_EC even when SCI_EVT is not set, but the reporter has complained
about AC/battery pluging/unpluging and video brightness change delay
on that platform.
This is because the work item that has issued QR_EC has to wait until
timeout in this case, and the _Qxx method evaluation work item queued
after QR_EC one is delayed.
It sounds reasonable to fix this issue by:
1. Implementing SCI_EVT sanity check before issuing QR_EC in the EC
driver's main state machine.
2. Moving QR_EC issuing out of the work queue used by _Qxx evaluation
to a seperate IRQ handling thread.
This patch fixes this issue using solution 1.
By disallowing QR_EC to be issued when SCI_EVT isn't set, we are able to
handle such platform in the EC driver's main state machine. This patch
enhances the state machine in this way to survive with such malfunctioning
EC firmware.
Note that this patch can also fix CLEAR_ON_RESUME quirk which also relies
on the assumption that the platforms are able to respond even when SCI_EVT
isn't set.
Fixes: c0d653412f ACPI / EC: Fix race condition in ec_transaction_completed()
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Reported-and-tested-by: Alexander Mezin <mezin.alexander@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Smatch detected two memory leaks on saved_ec:
drivers/acpi/ec.c:1070 acpi_ec_ecdt_probe() warn: possible
memory leak of 'saved_ec'
drivers/acpi/ec.c:1109 acpi_ec_ecdt_probe() warn: possible
memory leak of 'saved_ec'
Free saved_ec on these two error exit paths to stop the memory
leak. Note that saved_ec maybe null, but kfree on null is allowed.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Developers really don't need to translate EC_SC(R) in mind as long as the
field details are decoded in the debugging message.
Tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The bug fixes and asynchronous improvements have been done to the EC driver
by the previous commits. This patch increases the revision to 2.2 to
indicate the behavior differences between the old and the new drivers. The
copyright/authorship notices are also updated.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is a race condition in ec_transaction_completed().
When ec_transaction_completed() is called in the GPE handler, it could
return true because of (ec->curr == NULL). Then the wake_up() invocation
could complete the next command unexpectedly since there is no lock between
the 2 invocations. With the previous cleanup, the IBF=0 waiter race need
not be handled any more. It's now safe to return a flag from
advance_condition() to indicate the requirement of wakeup, the flag is
returned from a locked context.
The ec_transaction_completed() is now only invoked by the ec_poll() where
the ec->curr is ensured to be different from NULL.
After cleaning up, the EVT_SCI=1 check should be moved out of the wakeup
condition so that an EVT_SCI raised with (ec->curr == NULL) can trigger a
QR_SC command.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After we've added the first command byte write into advance_transaction(),
the IBF=0 waiter is duplicated with the command completion waiter
implemented in the ec_poll() because:
If IBF=1 blocked the first command byte write invoked in the task
context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed
out and retried again in the task context.
Remove this seperate and duplicate IBF=0 waiter. By doing so we can
reduce the overall number of times to access the EC_SC(R) status
register.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move the first command byte write into advance_transaction() so that all
EC register accesses that can affect the command processing state machine
can happen in this asynchronous state machine advancement function.
The advance_transaction() function then can be a complete implementation
of an asyncrhonous transaction for a single command so that:
1. The first command byte can be written in the interrupt context;
2. The command completion waiter can also be used to wait the first command
byte's timeout;
3. In BURST mode, the follow-up command bytes can be written in the
interrupt context directly, so that it doesn't need to return to the
task context. Returning to the task context reduces the throughput of
the BURST mode and in the worst cases where the system workload is very
high, this leads to the hardware driven automatic BURST mode exit.
In order not to increase memory consumption, convert 'done' into 'flags'
to contain multiple indications:
1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition,
indicating the completion of the command transaction.
2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first
command byte. A new command can utilize this flag to compete for the
right of accessing the underlying hardware. There is a follow-up bug
fix that has utilized this new flag.
The 2 flags are important because it also reflects a key concept of IO
programs' design used in the system softwares. Normally an IO program
running in the kernel should first be implemented in the asynchronous way.
And the 2 flags are the most common way to implement its synchronous
operations on top of the asynchronous operations:
1. POLL: This flag can be used to block until the asynchronous operations
can happen.
2. COMPLETE: This flag can be used to block until the asynchronous
operations have completed.
By constructing code cleanly in this way, many difficult problems can be
solved smoothly.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The advance_transaction() will be invoked from the IRQ context GPE handler
and the task context ec_poll(). The handling of this function is locked so
that the EC state machine are ensured to be advanced sequentially.
But there is a problem. Before invoking advance_transaction(), EC_SC(R) is
read. Then for advance_transaction(), there could be race condition around
the lock from both contexts. The first one reading the register could fail
this race and when it passes the stale register value to the state machine
advancement code, the hardware condition is totally different from when
the register is read. And the hardware accesses determined from the wrong
hardware status can break the EC state machine. And there could be cases
that the functionalities of the platform firmware are seriously affected.
For example:
1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may
be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the
hardware will either refuse to respond a next EC_SC(W) write of the next
command or discard the current WR_EC command when it receives a EC_SC(W)
write of the next command.
2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the
EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write.
The next EC_DATA(R) could never be responded by the hardware. This is
the root cause of the reported issue.
Fix this issue by moving the EC_SC(R) access into the lock so that we can
ensure that the state machine is advanced consistently.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Address a regression caused by commit ad332c8a45:
(ACPI / EC: Clear stale EC events on Samsung systems)
After the earlier patch, there was found to be a race condition on some
earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was
sometimes discarding a new EC event before its GPE was triggered by the
system. In the case of these systems, this meant that the "lid open"
event was not registered on resume if that was the cause of the wake,
leading to problems when attempting to close the lid to suspend again.
After testing on a number of Samsung systems, both those affected by the
previous EC bug and those affected by the race condition, it seemed that
the best course of action was to process rather than discard the events.
On Samsung systems which accumulate stale EC events, there does not seem
to be any adverse side-effects of running the associated _Q methods.
This patch adds an argument to the static function acpi_ec_sync_query so
that it may be used within the acpi_ec_clear loop in place of
acpi_ec_query_unlocked which was used previously.
With thanks to Stefan Biereigel for reporting the issue, and for all the
people who helped test the new patch on affected systems.
Fixes: ad332c8a45 (ACPI / EC: Clear stale EC events on Samsung systems)
References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173
Reported-by: Stefan Biereigel <stefan@biereigel.de>
Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com>
Tested-by: Stefan Biereigel <stefan@biereigel.de>
Tested-by: Dennis Jansen <dennis.jansen@web.de>
Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com>
Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com>
Tested-by: Kieran Clancy <clancy.kieran@gmail.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc)
continue to log events during sleep (lid open/close, AC plug/unplug,
battery level change), which accumulate in the EC until a buffer fills.
After the buffer is full (tests suggest it holds 8 events), GPEs stop
being triggered for new events. This state persists on wake or even on
power cycle, and prevents new events from being registered until the EC
is manually polled.
This is the root cause of a number of bugs, including AC not being
detected properly, lid close not triggering suspend, and low ambient
light not triggering the keyboard backlight. The bug also seemed to be
responsible for performance issues on at least one user's machine.
Juan Manuel Cabo found the cause of bug and the workaround of polling
the EC manually on wake.
The loop which clears the stale events is based on an earlier patch by
Lan Tianyu (see referenced attachment).
This patch:
- Adds a function acpi_ec_clear() which polls the EC for stale _Q
events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is
logged if this limit is reached.
- Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI
system vendor is Samsung. This check could be replaced by several
more specific DMI vendor/product pairs, but it's likely that the bug
affects more Samsung products than just the five series mentioned
above. Further, it should not be harmful to run acpi_ec_clear() on
systems without the bug; it will return immediately after finding no
data waiting.
- Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add()
- Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions()
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161
References: https://bugzilla.kernel.org/show_bug.cgi?id=45461
References: https://bugzilla.kernel.org/show_bug.cgi?id=57271
References: https://bugzilla.kernel.org/attachment.cgi?id=126801
Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com>
Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Dennis Jansen <dennis.jansen@web.de>
Tested-by: Kieran Clancy <clancy.kieran@gmail.com>
Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: Dennis Jansen <dennis.jansen@web.de>
Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: San Zamoyski <san@plusnet.pl>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpi-gpe:
ACPI / EC: disable GPE before removing GPE handler
ACPI / Button: Fix enabling button GPEs twice
* acpi-video:
ACPI: Blacklist Win8 OSI for some HP laptop 2013 models
ACPI / video: Fix typo in video_detect.c
* acpi-thermal:
ACPI / thermal: remove const from thermal_zone_device_ops declaration
* acpi-processor:
ACPI / scan: bail out early if failed to parse APIC ID for CPU
* acpi-sleep:
ACPI / sleep: remove panic in case hardware has changed after S4
Adds the prototype declarations of functions acpi_ec_add_query_handler()
and acpi_ec_remove_query_handler() in header file internal.h and removes
unused functions ec_burst_enable() and ec_burst_disable() in ec.c.
This eliminates the following warnings in ec.c:
drivers/acpi/ec.c:393:5: warning: no previous prototype for ‘ec_burst_enable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:402:5: warning: no previous prototype for ‘ec_burst_disable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:531:5: warning: no previous prototype for ‘acpi_ec_add_query_handler’ [-Wmissing-prototypes]
drivers/acpi/ec.c:552:6: warning: no previous prototype for ‘acpi_ec_remove_query_handler’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Adjust the order of disabling the EC GPE and removing its handler to
avoid unhandled events.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.
First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.
Second, there are ordering dependencies between those files that always
have to be met. Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there. And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds. That also is taken care of including
<linux/acpi.h> as appropriate.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A bug was introduced by commit b76b51ba0c ('ACPI / EC: Add more debug
info and trivial code cleanup') that erroneously caused the struct member
to be accessed before acquiring the required lock. This change fixes
it by ensuring the lock acquisition is done first.
Found by Aaron Durbin <adurbin@chromium.org>
Fixes: b76b51ba0c ('ACPI / EC: Add more debug info and trivial code cleanup')
References: http://crbug.com/319019
Signed-off-by: Puneet Kumar <puneetster@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
[olof: Commit message reworded a bit]
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: 3.8+ <stable@vger.kernel.org> # 3.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch is to convert all printks in the ec driver to pr_debug/info/err
and define pr_fmt macro to replace PREFIX.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
