[Intel-gfx] [PATCH] drm/i915: Move the irq_barrier for reset earlier into reset_prepare

[Chris Wilson]

When updating the bookkeeping following the reset, we need the seqno to
be coherent on the CPU prior to trusting its result for deciding whether
any request is completed. We need the irq_barrier before we start making
these decisions, i.e. in reset_prepare.

References: https://bugs.freedesktop.org/show_bug.cgi?id=99733
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ed60d5881b40..3066f94da8f0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2677,6 +2677,9 @@ int i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
 		tasklet_disable(&engine->irq_tasklet);
 		tasklet_kill(&engine->irq_tasklet);
 
+		if (engine->irq_seqno_barrier)
+			engine->irq_seqno_barrier(engine);
+
 		if (engine_stalled(engine)) {
 			request = i915_gem_find_active_request(engine);
 			if (request && request->fence.error == -EIO)
@@ -2773,9 +2776,6 @@ static void i915_gem_reset_engine(struct intel_engine_cs *engine)
 {
 	struct drm_i915_gem_request *request;
 
-	if (engine->irq_seqno_barrier)
-		engine->irq_seqno_barrier(engine);
-
 	request = i915_gem_find_active_request(engine);
 	if (request && i915_gem_reset_request(request)) {
 		DRM_DEBUG_DRIVER("resetting %s to restart from tail of request 0x%x\n",
-- 
2.11.0