Hi Ethan,

On 9/24/20 9:34 PM, Ethan Zhao 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.

Signed-off-by: Ethan Zhao <haifeng.z...@intel.com>
Tested-by: Wen jin <wen....@intel.com>
Tested-by: Shanshan Zhang <shanshanx.zh...@intel.com>
---
  drivers/pci/pci.h | 31 +++----------------------------
  1 file changed, 3 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fa12f7cbc1a0..d420bb977f3b 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -362,35 +362,10 @@ static inline bool pci_dev_set_io_state(struct pci_dev 
*dev,
        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)
+       if (dev->error_state != new) {
                dev->error_state = new;
+               changed = true;
+       }
        return changed;
  }

The flow is a lot easier to follow now. Thank you.

Reviewed-by: Alexandru Gagniuc <mr.nuke...@gmail.com>

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