Re: Oops when returning from hibernation with changed thunderbolt status

Re: Oops when returning from hibernation with changed thunderbolt status

[Lukas Wunner]

[cc += linux-efi]

On Thu, Nov 20, 2025 at 06:57:48AM +0100, Mika Westerberg wrote:
> On Wed, Nov 19, 2025 at 06:43:16PM +0100, Michael Guntsche wrote:
> > I started seeing this issue with kernel v6.15, it worked fine up to 6.14.
> > If my notebook went into hibernation with the docking station plugged
> > in and I then started it up again with the docking station unplugged
> > it would panic. Some times but not always it would also panic if the
> > dock was still connected.
> 
> Did you try to disable RTC_DRV_EFI? At least from the backtrace that's
> where it crashes.

The backtrace in the photo doesn't seem to betray what kind of call
was queued up on efi_rts_wq.  It doesn't have to be a set/get time
request.  efi_queue_work() is also called for set/get variable requests
among other things.  I recommend instrumenting __efi_queue_work()
with a call to dump_stack() to see where this is coming from.
Maybe add an msleep(5000) afterwards to allow time to take a picture.

Also the photo shows a UBSAN splat in drm/display/drm_mst_topology.c
220 msec before the oops, maybe it's related?

Thanks,

Lukas

Re: Oops when returning from hibernation with changed thunderbolt status

[Kenneth Crudup]

On 11/22/25 02:42, Lukas Wunner wrote:

> Also the photo shows a UBSAN splat in drm/display/drm_mst_topology.c
> 220 msec before the oops, maybe it's related?

FWIW, this sounds really familiar (resume crashes if I changed TB docks 
between suspend and resume) and was getting an OOPS there I'd bisected to:

Resume OOPS from f6971d7427 ("drm/i915/mst: adapt 
intel_dp_mtp_tu_compute_config() for 128b/132b SST") if MST displays 
disconnected while suspended

... and this was fixed in 732b87a (Fix determining SST/MST mode during 
MTP TU state computation) back in 6.15 (which IIRC, is when your crashes 
started happening).

I wonder if this is related? Maybe reach out to the i915 guys?

-Kenny

-- 
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange 
County CA

Re: Oops when returning from hibernation with changed thunderbolt status

[Michael Guntsche]

[cc +=maarten.lankhorst@linux.intel.com]

On Mon, Nov 24, 2025 at 7:02 PM Kenneth Crudup <kenny@panix.com> wrote:
>
>
>
> On 11/22/25 02:42, Lukas Wunner wrote:
>
> > Also the photo shows a UBSAN splat in drm/display/drm_mst_topology.c
> > 220 msec before the oops, maybe it's related?
>
> FWIW, this sounds really familiar (resume crashes if I changed TB docks
> between suspend and resume) and was getting an OOPS there I'd bisected to:
>
> Resume OOPS from f6971d7427 ("drm/i915/mst: adapt
> intel_dp_mtp_tu_compute_config() for 128b/132b SST") if MST displays
> disconnected while suspended
>
> ... and this was fixed in 732b87a (Fix determining SST/MST mode during
> MTP TU state computation) back in 6.15 (which IIRC, is when your crashes
> started happening).
>
> I wonder if this is related? Maybe reach out to the i915 guys?

I tried this now with 6.18 and got the same issues, now it even fails
for me  if I unplug the dock while hibernating.
The last entry I see is the UBSAN message and an out of bounds index error.

Re: Oops when returning from hibernation with changed thunderbolt status

[Kenneth Crudup]

On 12/1/25 11:09, Michael Guntsche wrote:

>> FWIW, this sounds really familiar (resume crashes if I changed TB docks
>> between suspend and resume) and was getting an OOPS there I'd bisected to:
>>
>> Resume OOPS from f6971d7427 ("drm/i915/mst: adapt
>> intel_dp_mtp_tu_compute_config() for 128b/132b SST") if MST displays
>> disconnected while suspended
>>
>> ... and this was fixed in 732b87a (Fix determining SST/MST mode during
>> MTP TU state computation) back in 6.15 (which IIRC, is when your crashes
>> started happening).
>>
>> I wonder if this is related? Maybe reach out to the i915 guys?
> 
> I tried this now with 6.18 and got the same issues, now it even fails
> for me  if I unplug the dock while hibernating.
> The last entry I see is the UBSAN message and an out of bounds index error.

I guess what I'm wondering is if the fix for me broke things for you ... 
can you revert that change in 6.15.1 and see if things unbreak for you?

-K

-- 
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange 
County CA