drm/i915/gt: Cancel the preemption timeout on responding to it

We currently presume that the engine reset is successful, cancelling the
expired preemption timer in the process. However, engine resets can
fail, leaving the timeout still pending and we will then respond to the
timeout again next time the tasklet fires. What we want is for the
failed engine reset to be promoted to a full device reset, which is
kicked by the heartbeat once the engine stops processing events.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1168
Fixes: 3a7a92aba8fb ("drm/i915/execlists: Force preemption")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-2-chris@chris-wilson.co.uk
(cherry picked from commit d997e240ceecb4f732611985d3a939ad1bfc1893)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 03fd1fa42a75a1f714e6bdacf4c48402d31e1bb8..724b2cb897d33f139cbb01aa6593b05b593b17d7 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3172,8 +3172,10 @@ static void execlists_submission_tasklet(unsigned long data)
                spin_unlock_irqrestore(&engine->active.lock, flags);
 
                /* Recheck after serialising with direct-submission */
-               if (unlikely(timeout && preempt_timeout(engine)))
+               if (unlikely(timeout && preempt_timeout(engine))) {
+                       cancel_timer(&engine->execlists.preempt);
                        execlists_reset(engine, "preemption time out");
+               }
        }
 }