From ed2ec71f9f7c0e1682c0821e4fa2452430f70e5e Mon Sep 17 00:00:00 2001 From: Oscar Mateo Date: Wed, 22 Mar 2017 10:39:51 -0700 Subject: [PATCH] drm/i915/guc: Wait for doorbell to be inactive before deallocating Doorbell release flow requires that we wait for GEN8_DRB_VALID bit to go to zero after updating db_status before we call the GuC to release the doorbell. Kudos to Daniele for finding this out. v2: WARN instead of DRM_ERROR (Joonas) Signed-off-by: Oscar Mateo Reviewed-by: Daniele Ceraolo Spurio Reviewed-by: Joonas Lahtinen Signed-off-by: Joonas Lahtinen --- drivers/gpu/drm/i915/i915_guc_submission.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index e98cb743090f..60add049b531 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -206,12 +206,22 @@ static int __create_doorbell(struct i915_guc_client *client) static int __destroy_doorbell(struct i915_guc_client *client) { + struct drm_i915_private *dev_priv = guc_to_i915(client->guc); struct guc_doorbell_info *doorbell; + u16 db_id = client->doorbell_id; + + GEM_BUG_ON(db_id >= GUC_DOORBELL_INVALID); doorbell = __get_doorbell(client); doorbell->db_status = GUC_DOORBELL_DISABLED; doorbell->cookie = 0; + /* Doorbell release flow requires that we wait for GEN8_DRB_VALID bit + * to go to zero after updating db_status before we call the GuC to + * release the doorbell */ + if (wait_for_us(!(I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID), 10)) + WARN_ONCE(true, "Doorbell never became invalid after disable\n"); + return __guc_deallocate_doorbell(client->guc, client->ctx_index); } -- 2.39.5