Commit f6ba181a authored Dec 16, 2017 by Chris Wilson

drm/i915: Skip an engine reset if it recovered before our preparations

At the beginning of a reset, we disable the submission method and find
the stuck request. We expect to find a stuck request for we have
declared the engine stalled. However, if we find no active request, the
engine must have recovered from its stall before we could issue a reset,
so let the engine continue on without a reset. If the engine is truly
stuck, we will back soon enough with the next reset attempt.

v2: Remove the stale debug message.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171216002206.31737-1-chris@chris-wilson.co.uk

parent 33aa69ed

drivers/gpu/drm/i915/i915_drv.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -2011,19 +2011,19 @@ int i915_reset_engine(struct intel_engine_cs *engine, unsigned int flags)

		GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags));

		active_request = i915_gem_reset_prepare_engine(engine);
		if (IS_ERR_OR_NULL(active_request)) {
		/* Either the previous reset failed, or we pardon the reset. */
		ret = PTR_ERR(active_request);
		goto out;
		}

		if (!(flags & I915_RESET_QUIET)) {
		dev_notice(engine->i915->drm.dev,
		"Resetting %s after gpu hang\n", engine->name);
		}
		error->reset_engine_count[engine->id]++;

		active_request = i915_gem_reset_prepare_engine(engine);
		if (IS_ERR(active_request)) {
		DRM_DEBUG_DRIVER("Previous reset failed, promote to full reset\n");
		ret = PTR_ERR(active_request);
		goto out;
		}

		if (!engine->i915->guc.execbuf_client)
		ret = intel_gt_reset_engine(engine->i915, engine);
		else