[Intel-gfx] [PATCH] drm/i915: Only reset hangcheck at the start of an activity cycle

[Chris Wilson]

Across a reset, the seqno (and thus hangcheck) should restart and the
hangcheck naturally progress, for when it does not, we want to declare an
emergency. Currently, we only detect if reset and reinit fails, but we
do not detect if the call to reinit succeeds but the HW is fried - as we
are resetting hangcheck on initialisation the engine. Remove that and
rely on the natural progress to reset the hangcheck timer.

References: e21b141376f9 ("drm/i915: Mark the hangcheck as idle when unparking the engines")
References: 1fd00c0faeec ("drm/i915: Declare the driver wedged if hangcheck makes no progress")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c        | 1 -
 drivers/gpu/drm/i915/intel_ringbuffer.c | 2 --
 2 files changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7b4dbe8746a4..c32603bd6fca 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1858,7 +1858,6 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
 		return ret;
 
 	intel_engine_reset_breadcrumbs(engine);
-	intel_engine_init_hangcheck(engine);
 
 	if (GEM_SHOW_DEBUG() && unexpected_starting_state(engine)) {
 		struct drm_printer p = drm_debug_printer(__func__);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 2637e3db0e80..5e6d2d79b617 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -525,8 +525,6 @@ static int init_ring_common(struct intel_engine_cs *engine)
 		goto out;
 	}
 
-	intel_engine_init_hangcheck(engine);
-
 	if (INTEL_GEN(dev_priv) > 2)
 		I915_WRITE_MODE(engine, _MASKED_BIT_DISABLE(STOP_RING));
 
-- 
2.18.0