Re: [PATCH v2] PCI/DPC: Increase recovery timeout to 60 seconds

[Bjorn Helgaas]

On Fri, Nov 06, 2026 at 04:56:55PM +0800, Ziyou Wang (Lenovo) wrote:
> Some NVMe devices need more than 5 seconds to recover after DPC
> containment, but pci_dpc_recovered() waits only 4 seconds.  If the device
> hasn't recovered by then, pciehp reports "device recovery failed" and
> the device is re-enumerated.
> 
> Move PCIE_RESET_READY_POLL_MS definition from pci.c to pci.h so it can be
> used in dpc.c.  Use PCIE_RESET_READY_POLL_MS (60 seconds) as the timeout
> so pciehp waits as long as pci_dev_wait() does, which is sufficient for
> all known devices.
> 
> Tested with INNOGRIT NVMe SSD [1dbe:5668] with ACS Fatal error
> injection:
> 
> Upstream kernel (7.3.0-master+, 4s timeout):
>   [123.018691] nvme: not ready 1023ms after DPC; waiting
>   [124.106690] nvme: not ready 2047ms after DPC; waiting

Was there a "not ready ... after DPC; giving up" message here?
pci_dev_wait() should log *something* about how it resolved this
situation.

>   [125.642703] pciehp: Slot(64): Link Down
>   [126.218696] AER: subordinate device reset failed
>   [126.218700] AER: device recovery failed
>   Device re-enumerated as nvme1
> 
> With this patch (60s timeout):
>   [74.894811] nvme: not ready 1023ms after DPC; waiting
>   [75.982813] nvme: not ready 2047ms after DPC; waiting
>   [78.094810] nvme: ready 4095ms after DPC
>   [78.094816] nvme: restart after slot reset
>   [78.111620] AER: device recovery successful
>   Device works normally
> 
> Fixes: a97396c6eb13 ("PCI: pciehp: Ignore Link Down/Up caused by DPC")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ziyou Wang (Lenovo) <ziyou.dev@xxxxxxxxxxx>
> ---

30 minutes after v1 is too soon to post a v2.  A couple days is a
reasonable interval.

v2 should include a note here (after the "---") about what changed
since v1 and ideally a lore link to the v1 posting.