Re: [PATCH] drm/i915/selftests: Wait longer for request to start

[Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>]

Hi Krzysztof,

On Tue, 2026-09-01 at 06:19 +0000, Krzysztof Karas wrote:
> Hi Janusz,
> 
> On 2026-08-31 at 11:33:08 +0200, Janusz Krzysztofik wrote:
> > CI extreamly sporadically (five times over last six mohths) reported
> extreamly -> extremely, mohths -> months

Heh, thanks, those were results of my last minute polishing, apparently
with spell checker off, sorry.

> 
> > failures of igt@i915_selftest@live@hangcheck on ARL-S machines.  The
> > selftest was timing out while waiting up to 1 second for a request
> > supposed to trigger a GPU hang to be started.  It occurred possible to
> > reproduce this issue manually by running the selftest in a loop for a
> > few hours.
> > 
> > Among results from 5 occurrences reported by CI so far, and two manual
> > reproductions, two of them contained messages that suggested a
> > posssibility of the awaited request to actually start soon after
> > timeout.  With the timeout extended from 1 to 2 seconds, it occurred no
> > longer possible to trigger the failure, even when running the test in a
> > loop for 10, then for 12 hours, on the same machine where it was failing
> > before in 2-3 hours.
> > 
> > Assume the conditions that prevented the hang requests to start within 1
> > second were always transient, and 2 seconds is sufficient for those
> > requests to start effectively on machines in the CI environment.  Fix
> > the issue by using that value as the timeout.
> > 
> > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16624
> > Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> > index 00dfc37221fac..53f3ce5c33a47 100644
> > --- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> > +++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> > @@ -278,7 +278,7 @@ static bool wait_until_running(struct hang *h, struct i915_request *rq)
> >  			     10) &&
> >  		 wait_for(i915_seqno_passed(hws_seqno(h, rq),
> >  					    rq->fence.seqno),
> > -			  1000));
> > +			  2000));
> >  }
> >  
> >  static int igt_hang_sanitycheck(void *arg)
> > -- 
> > 2.54.0
> > 
> 
> Patch is trivial, so:
> Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>

Thank you :-)

> 
> though, it would probably need a rebase, since it does not apply
> cleanly for CI build process.

Please note that was only a response from an attempt to apply the patch to
IGT sources (I sent a copy to igt-dev@lists.freedesktop.org).

Thanks,
Janusz