Messages in this thread Patch in this message | | | From | Ethan Zhao <> | Subject | [PATCH 4/5 V3] PCI: only return true when dev io state is really changed | Date | Sun, 27 Sep 2020 01:28:40 -0400 |
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When uncorrectable error happens, AER driver and DPC driver interrupt handlers likely call
pcie_do_recovery() ->pci_walk_bus() ->report_frozen_detected()
with pci_channel_io_frozen the same time. If pci_dev_set_io_state() return true even if the original state is pci_channel_io_frozen, that will cause AER or DPC handler re-enter the error detecting and recovery procedure one after another. The result is the recovery flow mixed between AER and DPC. So simplify the pci_dev_set_io_state() function to only return true when dev->error_state is changed.
Signed-off-by: Ethan Zhao <haifeng.zhao@intel.com> Tested-by: Wen Jin <wen.jin@intel.com> Tested-by: Shanshan Zhang <ShanshanX.Zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-by: Joe Perches <joe@perches.com> --- Changnes: V2: revise description and code according to suggestion from Andy. V3: Change code to simpler. drivers/pci/pci.h | 37 +++++-------------------------------- 1 file changed, 5 insertions(+), 32 deletions(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index fa12f7cbc1a0..a2c1c7d5f494 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -359,39 +359,12 @@ struct pci_sriov { static inline bool pci_dev_set_io_state(struct pci_dev *dev, pci_channel_state_t new) { - bool changed = false; - device_lock_assert(&dev->dev); - switch (new) { - case pci_channel_io_perm_failure: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - case pci_channel_io_perm_failure: - changed = true; - break; - } - break; - case pci_channel_io_frozen: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; - case pci_channel_io_normal: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; - } - if (changed) - dev->error_state = new; - return changed; + if (dev->error_state == new) + return false; + + dev->error_state = new; + return true; } static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused) -- 2.18.4
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