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

[Michal Pecio <michal.pecio@gmail.com>]

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