kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

ACPI: Add "acpi.power_nocheck=1" to disable power state check in power transition

Browse source 
Maybe the incorrect power state is returned on the bogus bios, which
is different with the real power state. For example: the bios returns D0
state and the real power state is D3. OS expects to set the device to D0
state. In  such case if OS uses the power state returned by the BIOS and
checks the device power state very strictly in power transition, the device
can't be transited to the correct power state.

   So the boot option of "acpi.power_nocheck=1" is added to avoid checking
the device power in the course of device power transition.

http://bugzilla.kernel.org/show_bug.cgi?id=8049
http://bugzilla.kernel.org/show_bug.cgi?id=11000

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Zhao Yakui 2008-08-11 14:57:50 +08:00 committed by Len Brown
parent eab4b64576
commit f5adfaa372
4 changed files with 53 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
Documentation/kernel-parameters.txt
View file

@ -251,6 +251,14 @@ and is between 256 and 4096 characters. It is defined in the file
Warning: Many of these options can produce a lot of
output and make your system unusable. Be very careful.
acpi.power_nocheck= [HW,ACPI]
Format: 1/0 enable/disable the check of power state.
On some bogus BIOS the _PSC object/_STA object of
power resource can't return the correct device power
state. In such case it is unneccessary to check its
power state again in power transition.
1 : disable the power state check
acpi_pm_good [X86-32,X86-64]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value

14
drivers/acpi/bus.c
View file

@ -223,7 +223,19 @@ int acpi_bus_set_power(acpi_handle handle, int state)
/*
* Get device's current power state
*/
acpi_bus_get_power(device->handle, &device->power.state);
if (!acpi_power_nocheck) {
/*
* Maybe the incorrect power state is returned on the bogus
* bios, which is different with the real power state.
* For example: the bios returns D0 state and the real power
* state is D3. OS expects to set the device to D0 state. In
* such case if OS uses the power state returned by the BIOS,
* the device can't be transisted to the correct power state.
* So if the acpi_power_nocheck is set, it is unnecessary to
* get the power state by calling acpi_bus_get_power.
*/
acpi_bus_get_power(device->handle, &device->power.state);
}
if ((state == device->power.state) && !device->flags.force_power_state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
state));

42
drivers/acpi/power.c
View file

@ -54,6 +54,14 @@ ACPI_MODULE_NAME("power");
#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
#define ACPI_POWER_RESOURCE_STATE_ON 0x01
#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
#ifdef MODULE_PARAM_PREFIX
#undef MODULE_PARAM_PREFIX
#endif
#define MODULE_PARAM_PREFIX "acpi."
int acpi_power_nocheck;
module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
static int acpi_power_add(struct acpi_device *device);
static int acpi_power_remove(struct acpi_device *device, int type);
static int acpi_power_resume(struct acpi_device *device);
@ -228,12 +236,18 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
result = acpi_power_get_state(resource->device->handle, &state);
if (result)
return result;
if (state != ACPI_POWER_RESOURCE_STATE_ON)
return -ENOEXEC;
if (!acpi_power_nocheck) {
/*
* If acpi_power_nocheck is set, it is unnecessary to check
* the power state after power transition.
*/
result = acpi_power_get_state(resource->device->handle,
&state);
if (result)
return result;
if (state != ACPI_POWER_RESOURCE_STATE_ON)
return -ENOEXEC;
}
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D0;
@ -279,11 +293,17 @@ static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
result = acpi_power_get_state(handle, &state);
if (result)
return result;
if (state != ACPI_POWER_RESOURCE_STATE_OFF)
return -ENOEXEC;
if (!acpi_power_nocheck) {
/*
* If acpi_power_nocheck is set, it is unnecessary to check
* the power state after power transition.
*/
result = acpi_power_get_state(handle, &state);
if (result)
return result;
if (state != ACPI_POWER_RESOURCE_STATE_OFF)
return -ENOEXEC;
}
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D3;

1
include/acpi/acpi_drivers.h
View file

@ -93,6 +93,7 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state);
int acpi_disable_wakeup_device_power(struct acpi_device *dev);
int acpi_power_get_inferred_state(struct acpi_device *device);
int acpi_power_transition(struct acpi_device *device, int state);
extern int acpi_power_nocheck;
#endif
/* --------------------------------------------------------------------------