Re: [PATCH v22] PCI: Avoid D3 at suspend for AMD PCIe root ports w/ USB4 controllers

[Lukas Wunner <lukas@wunner.de>]

On Thu, Oct 05, 2023 at 01:52:34PM -0500, Mario Limonciello wrote:
> On 10/5/2023 13:47, Lukas Wunner wrote:
> > One belated thought I have on this is that it might be a better fit in
> > arch/x86/pci/fixups.c rather than drivers/pci/quirks.c.
> > 
> > The latter contains quirks for cards which could appear in any machine,
> > regardless of the arch.  But this seems to be specific to x86 machines.
> > I understand these xhci controllers are built into the SoC.
> > 
> > We've had complaints in the past from developers working with
> > space-constrained Mips routers that the generic quirks in
> > drivers/pci/quirks.c occupy too much memory:
> > 
> > https://lore.kernel.org/all/1482306784-29224-1-git-send-email-john@phrozen.org/
> > 
> > To cater to their needs, we need to keep in mind that arch-specific
> > quirks are kept outside of drivers/pci/quirks.c.
> > 
> > I apologize that this didn't occur to me earlier.
> 
> This seems like a bigger problem than this quirk.
> On a 6.5.y checkout I have on hand:
> 
> $ cat drivers/pci/quirks.c  | grep "VENDOR_ID_INTEL\|VENDOR_ID_AMD" | wc -l
> 412
> 
> Maybe we should move it all as a later follow up?

It's not that simple.  Some of these are for discrete chips which
may appear in any machine of any arch (think GPUs, Ethernet chips,
USB controllers etc, you might see these attached to a Raspberry Pi
and whatnot).

Thanks,

Lukas