[4/6] drm/i915: Fail engine initialization if LRCA is incorrectly aligned
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Message ID 1452184581-21075-5-git-send-email-tvrtko.ursulin@linux.intel.com
State New
Headers show

Commit Message

Tvrtko Ursulin Jan. 7, 2016, 4:36 p.m. UTC
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

LRCA can change only when it goes from unpinned to pinned so it
makes sense to check its alignment at that point rather than at
every batch buffer submission.

Furthermore, if we check it at pin time we can actually
gracefuly fail the engine initialization rather than just
spamming the logs at runtime with WARNs.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Chris Wilson Jan. 7, 2016, 4:44 p.m. UTC | #1
On Thu, Jan 07, 2016 at 04:36:19PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> LRCA can change only when it goes from unpinned to pinned so it
> makes sense to check its alignment at that point rather than at
> every batch buffer submission.
> 
> Furthermore, if we check it at pin time we can actually
> gracefuly fail the engine initialization rather than just
> spamming the logs at runtime with WARNs.

It's an impossible condition, so ENODEV. Still this was superseded by
patches last year...
-Chris

Patch
diff mbox

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 84977a6e6f3f..b9d5862c01c9 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -302,8 +302,6 @@  uint64_t intel_lr_context_descriptor(struct intel_context *ctx,
 	uint64_t lrca = i915_gem_obj_ggtt_offset(ctx_obj) +
 			LRC_PPHWSP_PN * PAGE_SIZE;
 
-	WARN_ON(lrca & 0xFFFFFFFF00000FFFULL);
-
 	desc |= lrca;
 	desc |= (u64)intel_execlists_ctx_id(ctx_obj) << GEN8_CTX_ID_SHIFT;
 
@@ -1030,6 +1028,7 @@  static int intel_lr_context_do_pin(struct intel_engine_cs *ring,
 {
 	struct drm_device *dev = ring->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	u64 lrca;
 	int ret = 0;
 
 	WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex));
@@ -1038,6 +1037,12 @@  static int intel_lr_context_do_pin(struct intel_engine_cs *ring,
 	if (ret)
 		return ret;
 
+	lrca = i915_gem_obj_ggtt_offset(ctx_obj) + LRC_PPHWSP_PN * PAGE_SIZE;
+	if (WARN_ON(lrca & 0xFFFFFFFF00000FFFULL)) {
+		ret = -EINVAL;
+		goto unpin_ctx_obj;
+	}
+
 	ret = intel_pin_and_map_ringbuffer_obj(ring->dev, ringbuf);
 	if (ret)
 		goto unpin_ctx_obj;