| Message ID | 20200928040651.24937-5-haifeng.zhao@intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Fix DPC hotplug race and enhance error handling | expand |
On Mon, Sep 28, 2020 at 7:13 AM Ethan Zhao <haifeng.zhao@intel.com> wrote: > > 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. > This one looks good (more or less) now. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > 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: Alexandru Gagniuc <mr.nuke.me@gmail.com> > --- > Changnes: > V2: revise description and code according to suggestion from Andy. > V3: change code to simpler. > V4: no change. > V5: no change. > > 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 >
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)
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: Alexandru Gagniuc <mr.nuke.me@gmail.com> --- Changnes: V2: revise description and code according to suggestion from Andy. V3: change code to simpler. V4: no change. V5: no change. drivers/pci/pci.h | 37 +++++-------------------------------- 1 file changed, 5 insertions(+), 32 deletions(-)