Re: [PATCH] pci: allow user specifiy a reset wait timeout

[Lukas Wunner <lukas@wunner.de>]

On Fri, Feb 07, 2025 at 12:43:10PM -0800, Keith Busch wrote:
> The spec does not provide any upper limit to how long a device may
> return Request Retry Status. It just says "Some devices require a
> lengthy self-initialization sequence to complete". The kernel
> arbitrarily chose 60 seconds since that really ought to be enough. But
> there are devices where this turns out not to be enough.
> 
> Since any timeout choice would be arbitrary, and 60 seconds is generally
> more than enough for the majority of hardware, let's make this a
> parameter so an admin can adjust it specifically to their needs if the
> default timeout isn't appropriate.

There are d3hot_delay and d3cold_delay members in struct pci_dev.
How about adding a reset_delay which can be set in a device-specific
quirk?  I think I'd prefer that over a command line parameter.

A D3cold -> D0 transition implies a reset, but I'm not sure it's
appropriate to (ab)use d3cold_delay as a reset_delay.

Thanks,

Lukas