Re: [PATCH] usb: pci-quirks: always assert xHCI OS ownership

[Mario Limonciello]

On 8/18/26 17:15, Michal Pecio wrote:
> On Sun, 16 Aug 2026 16:00:47 -0500, Mario Limonciello wrote:
> > On 8/16/26 15:03, Michal Pecio wrote:
> > > Not sure if this has anything to do with PROM21, or if some BIOS
> > > is just trying to use the xHC at resume because it's permitted to.
> > > Then it makes too many changes for Restore State to still work.
> > >
> > > Potentially, such bugs may have happened and been left unsolved or
> > > "solved" with RESET_ON_RESUME quirks and other hacks.
> >
> > What do you think about making this a series with each of those
> > quirks dropped one-by-one?  The head patch (a variation of this one)
> > could go to stable and the rest of the commits dropping those can go
> > to linux-next.
>
> Hard to tell. All we have is a wild theory. I couldn't even test what
> happens when the BIOS claims an unclaimed xHC during resume from S3,
> because my BIOS doesn't do that even when I clear the "OS owned" bit
> before suspending.
>
> Those quirks may be wrong in the sense that they weren't specific to
> the particular PCI IDs, but to some particular buggy BIOSes or kernels
> in the past. Maybe those problems don't exist, maybe they still do.
>
> I have completely disabled RESET_ON_RESUME on my test system with no
> apparent ill efects so far.
>
> OTOH, I tried disabling the "broken streams (UAS)" quirk on ASM1042.
> While the kernel crash which those chips used to cause has been fixed
> long ago, it turns out they just don't work correctly (Set TR Deq is
> a No-Op with streams). So I'm not rushing to remove this quirk.
>
> Regards,
> Michal

So maybe we try with dropping RESET_ON_RESUME quirks only in this go around.