Re: kernel NULL pointer dereference in quirk_clear_strap_no_soft_reset_dev2_f0 -> amd_smn_read

[Yazen Ghannam]

On Tue, Jan 13, 2026 at 02:01:34AM +0100, Marek Marczykowski-Górecki wrote:
> Hi,
> 
> I've got a report that kernel 6.17.9 crashes when running a Xen HVM domU
> with AMD Raphael/Granite Ridge USB controller passed through.
> It worked correctly in 6.12.59. Between those versions, I don't see any
> relevant change to quirk_clear_strap_no_soft_reset_dev2_f0() function,
> but the AMD node driver did got some changes, so my guess is one of them
> is to blame. I know the good-bad range is huge, but there aren't that
> many changes to the AMD node driver in this range.
> 
> It's running on Qubes OS 4.3, which uses Xen 4.19, and does PCI
> passthrough of USB controllers to a dedicated VM (HVM).
> 

Hi Marek,

Can you please test with the following patch?
adbf61cc47cb ("x86/acpi/boot: Correct acpi_is_processor_usable() check again")

This is in the TIP maintainers repo and linux-next.

Thanks,
Yazen