Re: [PATCH] PCI/DPC: Extend DPC recovery timeout

[Keith Busch <kbusch@kernel.org>]

On Wed, Aug 06, 2025 at 04:34:09PM -0500, Bjorn Helgaas wrote:
> > > However, the current 4 seconds timeout in pci_dpc_recovered() is indeed
> > > an empirical value rather than a hard requirement from the PCIe
> > > specification. In real-world scenarios, like with Mellanox ConnectX-5/7
> > > adapters, we've observed that full DPC recovery can take more than 5-6
> > > seconds, which leads to premature hotplug processing and device removal.
> > 
> > I think Sathya's point was:  Have you made an effort to talk to the
> > vendor and ask them to root-cause and fix the issue e.g. with a firmware
> > update.
> 
> Would definitely be great, but unless we have a number in the spec to
> point to, they might just shrug and ask what the requirement is.

I agree, and I have similar problems with other arbitrary kernel timing
decicsions. Specifically RRL where there's no spec defined number yet my
patch to modify it has not received much consideration.

  https://lore.kernel.org/linux-pci/20250218165444.2406119-1-kbusch@meta.com/