4.4-stable review patch. If anyone has any objections, please let me know.
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From: Gabriele Paoloni gabriele.paoloni@huawei.com
[ Upstream commit 86acc790717fb60fb51ea3095084e331d8711c74 ]
Previously, if an non-fatal error was reported by an endpoint, we called report_error_detected() for the endpoint, every sibling on the bus, and their descendents. If any of them did not implement the .error_detected() method, do_recovery() failed, leaving all these devices unrecovered.
For example, the system described in the bugzilla below has two devices:
0000:74:02.0 [19e5:a230] SAS controller, driver has .error_detected() 0000:74:03.0 [19e5:a235] SATA controller, driver lacks .error_detected()
When a device such as 74:02.0 reported a non-fatal error, do_recovery() failed because 74:03.0 lacked an .error_detected() method. But per PCIe r3.1, sec 6.2.2.2.2, such an error does not compromise the Link and does not affect 74:03.0:
Non-fatal errors are uncorrectable errors which cause a particular transaction to be unreliable but the Link is otherwise fully functional. Isolating Non-fatal from Fatal errors provides Requester/Receiver logic in a device or system management software the opportunity to recover from the error without resetting the components on the Link and disturbing other transactions in progress. Devices not associated with the transaction in error are not impacted by the error.
Report non-fatal errors only to the endpoint that reported them. We really want to check for AER_NONFATAL here, but the current code structure doesn't allow that. Looking for pci_channel_io_normal is the best we can do now.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197055 Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver") Signed-off-by: Gabriele Paoloni gabriele.paoloni@huawei.com Signed-off-by: Dongdong Liu liudongdong3@huawei.com [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas bhelgaas@google.com
Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/pcie/aer/aerdrv_core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -388,7 +388,14 @@ static pci_ers_result_t broadcast_error_ * If the error is reported by an end point, we think this * error is related to the upstream link of the end point. */ - pci_walk_bus(dev->bus, cb, &result_data); + if (state == pci_channel_io_normal) + /* + * the error is non fatal so the bus is ok, just invoke + * the callback for the function that logged the error. + */ + cb(dev, &result_data); + else + pci_walk_bus(dev->bus, cb, &result_data); }
return result_data.result;