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PCI: Handle FLR failure and allow other reset types

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pci_flr_wait() and pci_af_flr() functions assume graceful return even
though the device is inaccessible under error conditions.

Return -ENOTTY in error cases so that __pci_reset_function_locked() can
try other reset types if AF_FLR/FLR reset fails.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Sinan Kaya 2018-02-27 14:14:08 -06:00 committed by Bjorn Helgaas
parent cb5e0d060f
commit 91295d79d6
2 changed files with 11 additions and 9 deletions
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18
drivers/pci/pci.c
View file

@ -4017,7 +4017,7 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev)
}
EXPORT_SYMBOL(pci_wait_for_pending_transaction);
static void pci_flr_wait(struct pci_dev *dev)
static int pci_flr_wait(struct pci_dev *dev)
{
int delay = 1, timeout = 60000;
u32 id;
@ -4046,7 +4046,7 @@ static void pci_flr_wait(struct pci_dev *dev)
if (delay > timeout) {
pci_warn(dev, "not ready %dms after FLR; giving up\n",
100 + delay - 1);
return;
return -ENOTTY;
}
if (delay > 1000)
@ -4060,6 +4060,8 @@ static void pci_flr_wait(struct pci_dev *dev)
if (delay > 1000)
pci_info(dev, "ready %dms after FLR\n", 100 + delay - 1);
return 0;
}
/**
@ -4088,13 +4090,13 @@ static bool pcie_has_flr(struct pci_dev *dev)
* device supports FLR before calling this function, e.g. by using the
* pcie_has_flr() helper.
*/
void pcie_flr(struct pci_dev *dev)
int pcie_flr(struct pci_dev *dev)
{
if (!pci_wait_for_pending_transaction(dev))
pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
pci_flr_wait(dev);
return pci_flr_wait(dev);
}
EXPORT_SYMBOL_GPL(pcie_flr);
@ -4127,8 +4129,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
pci_flr_wait(dev);
return 0;
return pci_flr_wait(dev);
}
/**
@ -4379,8 +4380,9 @@ int __pci_reset_function_locked(struct pci_dev *dev)
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev)) {
pcie_flr(dev);
return 0;
rc = pcie_flr(dev);
if (rc != -ENOTTY)
return rc;
}
rc = pci_af_flr(dev, 0);
if (rc != -ENOTTY)

2
include/linux/pci.h
View file

@ -1082,7 +1082,7 @@ int pcie_get_mps(struct pci_dev *dev);
int pcie_set_mps(struct pci_dev *dev, int mps);
int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width);
void pcie_flr(struct pci_dev *dev);
int pcie_flr(struct pci_dev *dev);
int __pci_reset_function_locked(struct pci_dev *dev);
int pci_reset_function(struct pci_dev *dev);
int pci_reset_function_locked(struct pci_dev *dev);