On Thu, Jul 11, 2024 at 04:28:53PM +0000, Cavitt, Jonathan wrote: > -----Original Message----- > From: Intel-gfx <[email protected]> On Behalf Of Nitin > Gote > Sent: Thursday, July 11, 2024 9:32 AM > To: Wilson, Chris P <[email protected]>; [email protected]; > [email protected] > Cc: [email protected]; Shyti, Andi <[email protected]>; Das, > Nirmoy <[email protected]>; [email protected]; Gote, > Nitin R <[email protected]>; Chris Wilson > <[email protected]>; [email protected] > Subject: [PATCH v3] drm/i915/gt: Do not consider preemption during > execlists_dequeue for gen8 > > > > We're seeing a GPU HANG issue on a CHV platform, which was caused by > > bac24f59f454 ("drm/i915/execlists: Enable coarse preemption boundaries for > > gen8"). > > > > Gen8 platform has only timeslice and doesn't support a preemption mechanism > > as engines do not have a preemption timer and doesn't send an irq if the > > preemption timeout expires. > > That seems to mean the original can_preempt function was inaccurately built, > so fixing it here makes the most sense to me, especially if it's causing > problems. > > Reviewed-by: Jonathan Cavitt <[email protected]> > -Jonathan Cavitt > > > So, add a fix to not consider preemption > > during dequeuing for gen8 platforms. > > > > v2: Simplify can_preempt() function (Tvrtko Ursulin) > > > > v3: > > - Inside need_preempt(), condition of can_preempt() is not required > > as simplified can_preempt() is enough. (Chris Wilson) > > > > Fixes: bac24f59f454 ("drm/i915/execlists: Enable coarse preemption > > boundaries for gen8")
Something strange in here... This patch is not using directly or indirectly (I915_ENGINE_HAS_PREEMPTION) the can_preempt()... > > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11396 > > Suggested-by: Andi Shyti <[email protected]> > > Signed-off-by: Nitin Gote <[email protected]> > > Cc: Chris Wilson <[email protected]> > > CC: <[email protected]> # v5.2+ > > --- > > drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 6 +----- > > 1 file changed, 1 insertion(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > index 21829439e686..72090f52fb85 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > @@ -3315,11 +3315,7 @@ static void remove_from_engine(struct i915_request > > *rq) > > > > static bool can_preempt(struct intel_engine_cs *engine) > > { > > - if (GRAPHICS_VER(engine->i915) > 8) > > - return true; > > - > > - /* GPGPU on bdw requires extra w/a; not implemented */ > > - return engine->class != RENDER_CLASS; > > + return GRAPHICS_VER(engine->i915) > 8; > > } > > > > static void kick_execlists(const struct i915_request *rq, int prio) > > -- > > 2.25.1 > > > >
