[PATCH v16 1/9] PCI/ERR: Update error status after reset_link()

sathyanarayanan.kuppuswamy
2020-02-28T01:03:11Z

Commit bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") uses
reset_link() to recover from fatal errors. But during fatal error
recovery, if the initial value of error status is
PCI_ERS_RESULT_DISCONNECT or PCI_ERS_RESULT_NO_AER_DRIVER then
even after successful recovery (using reset_link()) pcie_do_recovery()
will report the recovery result as failure. So update the status of
error after reset_link().

You can reproduce this issue by triggering a SW DPC using "DPC
Software Trigger" bit in "DPC Control Register". You should see recovery
failed dmesg log as below.

[ 164.659982] pcieport 0000:00:16.0: DPC: containment event,
status:0x1f27 source:0x0000
[ 164.659989] pcieport 0000:00:16.0: DPC: software trigger detected
[ 164.659994] pci 0000:04:00.0: AER: can't recover (no error_detected
callback)
[ 164.794300] pcieport 0000:00:16.0: AER: device recovery failed

Fixes: bdb5ac85777d ("PCI/ERR: Handle fatal error recovery")
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Keith Busch <keith.busch@intel.com>
---
drivers/pci/pcie/err.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 01dfc8bb7ca0..eefefe03857a 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -208,9 +208,11 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
else
pci_walk_bus(bus, report_normal_detected, &status);

- if (state == pci_channel_io_frozen &&
- reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED)
- goto failed;
+ if (state == pci_channel_io_frozen) {
+ status = reset_link(dev, service);
+ if (status != PCI_ERS_RESULT_RECOVERED)
+ goto failed;
+ }

if (status == PCI_ERS_RESULT_CAN_RECOVER) {
status = PCI_ERS_RESULT_RECOVERED;
--
2.21.0