On 10/10/2020 6:16 PM, Hedi Berriche wrote:
> Commit 6d2c89441571 ("PCI/ERR: Update error status after reset_link()")
> broke pcie_do_recovery(): updating status after reset_link() has the ill
> side effect of causing recovery to fail if the error status is
> PCI_ERS_RESULT_CAN_RECOVER or PCI_ERS_RESULT_NEED_RESET as the following
> code will *never* run in the case of a successful reset_link()
>
> 177 if (status == PCI_ERS_RESULT_CAN_RECOVER) {
> ...
> 181 }
>
> 183 if (status == PCI_ERS_RESULT_NEED_RESET) {
> ...
> 192 }
>
> For instance in the case of PCI_ERS_RESULT_NEED_RESET we end up not
> calling ->slot_reset() (because we skip report_slot_reset()) thus
> breaking driver (re)initialisation.
>
> Don't clobber status with the return value of reset_link(); set status
> to PCI_ERS_RESULT_RECOVERED, in case of successful link reset, if and
> only if the initial value of error status is PCI_ERS_RESULT_DISCONNECT
> or PCI_ERS_RESULT_NO_AER_DRIVER.
>
> Fixes: 6d2c89441571 ("PCI/ERR: Update error status after reset_link()")
> Signed-off-by: Hedi Berriche <hedi.berri...@hpe.com>
> Cc: Russ Anderson <r...@hpe.com>
> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppusw...@linux.intel.com>
> Cc: Bjorn Helgaas <bhelg...@google.com>
> Cc: Ashok Raj <ashok....@intel.com>
> Cc: Joerg Roedel <jroe...@suse.com>
>
> Cc: sta...@kernel.org # v5.7+
> ---
> drivers/pci/pcie/err.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index c543f419d8f9..2730826cfd8a 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -165,10 +165,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> pci_dbg(dev, "broadcast error_detected message\n");
> if (state == pci_channel_io_frozen) {
> pci_walk_bus(bus, report_frozen_detected, &status);
> - status = reset_link(dev);
> - if (status != PCI_ERS_RESULT_RECOVERED) {
> + if (reset_link(dev) != PCI_ERS_RESULT_RECOVERED) {
> pci_warn(dev, "link reset failed\n");
> goto failed;
> + } else {
> + if (status == PCI_ERS_RESULT_DISCONNECT ||
> + status == PCI_ERS_RESULT_NO_AER_DRIVER)
> + status = PCI_ERS_RESULT_RECOVERED;
> }
> } else {
> pci_walk_bus(bus, report_normal_detected, &status);
>
Reviewed-by: Sinan Kaya <ok...@kernel.org>
