[RFC PATCH 24/97] drm/i915/guc: Add flag for mark broken CTB

[Matthew Brost]

From: Michal Wajdeczko <michal.wajdeczko at intel.com>

Once CTB descriptor is found in error state, either set by GuC
or us, there is no need continue checking descriptor any more,
we can rely on our internal flag.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 13 +++++++++++--
 drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h |  2 ++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
index 1afdeac683b5..178f73ab2c96 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -123,6 +123,7 @@ static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
 
 static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)
 {
+	ctb->broken = false;
 	guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size);
 }
 
@@ -365,9 +366,12 @@ static int ct_write(struct intel_guc_ct *ct,
 	u32 *cmds = ctb->cmds;
 	unsigned int i;
 
-	if (unlikely(desc->is_in_error))
+	if (unlikely(ctb->broken))
 		return -EPIPE;
 
+	if (unlikely(desc->is_in_error))
+		goto corrupted;
+
 	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
 		     (tail | head) >= size))
 		goto corrupted;
@@ -423,6 +427,7 @@ static int ct_write(struct intel_guc_ct *ct,
 	CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n",
 		 desc->addr, desc->head, desc->tail, desc->size);
 	desc->is_in_error = 1;
+	ctb->broken = true;
 	return -EPIPE;
 }
 
@@ -608,9 +613,12 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
 	unsigned int i;
 	u32 header;
 
-	if (unlikely(desc->is_in_error))
+	if (unlikely(ctb->broken))
 		return -EPIPE;
 
+	if (unlikely(desc->is_in_error))
+		goto corrupted;
+
 	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
 		     (tail | head) >= size))
 		goto corrupted;
@@ -674,6 +682,7 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
 	CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n",
 		 desc->addr, desc->head, desc->tail, desc->size);
 	desc->is_in_error = 1;
+	ctb->broken = true;
 	return -EPIPE;
 }
 
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
index cb222f202301..7d3cd375d6a7 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
@@ -32,12 +32,14 @@ struct intel_guc;
  * @desc: pointer to the buffer descriptor
  * @cmds: pointer to the commands buffer
  * @size: size of the commands buffer
+ * @broken: flag to indicate if descriptor data is broken
  */
 struct intel_guc_ct_buffer {
 	spinlock_t lock;
 	struct guc_ct_buffer_desc *desc;
 	u32 *cmds;
 	u32 size;
+	bool broken;
 };
 
 
-- 
2.28.0