Re: [PATCH 09/13] PCI: aardvark: Implement re-issuing config requests on CRS response

Marek Behún
2021-10-04T07:21:53Z

On Sat, 2 Oct 2021 11:35:19 -0500
Bjorn Helgaas <helgaas@kernel.org> wrote:

> On Fri, Oct 01, 2021 at 09:58:52PM +0200, Marek Behún wrote:
> > From: Pali Rohár <pali@kernel.org>
> >
> > Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") fixed
> > handling of CRS response and when CRSSVE flag was not enabled it marked CRS
> > response as failed transaction (due to simplicity).
> >
> > But pci-aardvark.c driver is already waiting up to the PIO_RETRY_CNT count
> > for PIO config response and so we can with a small change implement
> > re-issuing of config requests as described in PCIe base specification.
> >
> > This change implements re-issuing of config requests when response is CRS.
> > Set upper bound of wait cycles to around PIO_RETRY_CNT, afterwards the
> > transaction is marked as failed and an all-ones value is returned as
> > before.
>
> Does this fix a problem?

Hello Bjorn,

Pali has suspisions that certain Marvell WiFi cards may need this [1]
to work, but we do not have them so we cannot test this.

I guess you think this should be considered a new feature instead of a
fix, so that the Fixes tag should be removed, yes? Pali was of the
opinion that this patch "fixes" the driver to conform more to the PCIe
specification, that is why we added the Fixes tag.

Anyway if you think this should be considered a new feature, this patch
can be skipped. The following patches apply even without it.

Marek

[1]