diff mbox series

[RFC,11/97] drm/i915/guc: Only rely on own CTB size

Message ID 20210506191451.77768-12-matthew.brost@intel.com (mailing list archive)
State New, archived
Headers show
Series Basic GuC submission support in the i915 | expand

Commit Message

Matthew Brost May 6, 2021, 7:13 p.m. UTC 
From: Michal Wajdeczko <michal.wajdeczko@intel.com>

In upcoming GuC firmware, CTB size will be removed from the CTB
descriptor so we must keep it locally for any calculations.

While around, improve some debug messages and helpers.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 55 +++++++++++++++++------
 drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h |  2 +
 2 files changed, 43 insertions(+), 14 deletions(-)

Comments

Matthew Brost May 25, 2021, 2:47 a.m. UTC | #1 
On Thu, May 06, 2021 at 12:13:25PM -0700, Matthew Brost wrote:
> From: Michal Wajdeczko <michal.wajdeczko@intel.com>
> 
> In upcoming GuC firmware, CTB size will be removed from the CTB
> descriptor so we must keep it locally for any calculations.
> 
> While around, improve some debug messages and helpers.
> 

desc->size is still used in the patch and really shouldn't be per this
comment but a patch later in the series drops it. Seeing as this patch
and that patch are going to squashed into a single patch upgrading the
GuC firmware I think that is ok.

With that:
Reviewed-by: Matthew Brost <matthew.brost@intel.com> 

> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 55 +++++++++++++++++------
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h |  2 +
>  2 files changed, 43 insertions(+), 14 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 4cc8c0b71699..dbece569fbe4 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> @@ -90,6 +90,24 @@ static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
>  	desc->owner = CTB_OWNER_HOST;
>  }
>  
> +static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)
> +{
> +	guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size);
> +}
> +
> +static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,
> +			       struct guc_ct_buffer_desc *desc,
> +			       u32 *cmds, u32 size)
> +{
> +	GEM_BUG_ON(size % 4);
> +
> +	ctb->desc = desc;
> +	ctb->cmds = cmds;
> +	ctb->size = size;
> +
> +	guc_ct_buffer_reset(ctb, 0);
> +}
> +
>  static int guc_action_register_ct_buffer(struct intel_guc *guc,
>  					 u32 desc_addr,
>  					 u32 type)
> @@ -148,7 +166,10 @@ static int ct_deregister_buffer(struct intel_guc_ct *ct, u32 type)
>  int intel_guc_ct_init(struct intel_guc_ct *ct)
>  {
>  	struct intel_guc *guc = ct_to_guc(ct);
> +	struct guc_ct_buffer_desc *desc;
> +	u32 blob_size;
>  	void *blob;
> +	u32 *cmds;
>  	int err;
>  	int i;
>  
> @@ -176,19 +197,24 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
>  	 * other code will need updating as well.
>  	 */
>  
> -	err = intel_guc_allocate_and_map_vma(guc, PAGE_SIZE, &ct->vma, &blob);
> +	blob_size = PAGE_SIZE;
> +	err = intel_guc_allocate_and_map_vma(guc, blob_size, &ct->vma, &blob);
>  	if (unlikely(err)) {
> -		CT_ERROR(ct, "Failed to allocate CT channel (err=%d)\n", err);
> +		CT_PROBE_ERROR(ct, "Failed to allocate %u for CTB data (%pe)\n",
> +			       blob_size, ERR_PTR(err));
>  		return err;
>  	}
>  
> -	CT_DEBUG(ct, "vma base=%#x\n", intel_guc_ggtt_offset(guc, ct->vma));
> +	CT_DEBUG(ct, "base=%#x size=%u\n", intel_guc_ggtt_offset(guc, ct->vma), blob_size);
>  
>  	/* store pointers to desc and cmds */
>  	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
>  		GEM_BUG_ON((i !=  CTB_SEND) && (i != CTB_RECV));
> -		ct->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
> -		ct->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
> +
> +		desc = blob + PAGE_SIZE / 4 * i;
> +		cmds = blob + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
> +
> +		guc_ct_buffer_init(&ct->ctbs[i], desc, cmds, PAGE_SIZE / 4);
>  	}
>  
>  	return 0;
> @@ -217,7 +243,7 @@ void intel_guc_ct_fini(struct intel_guc_ct *ct)
>  int intel_guc_ct_enable(struct intel_guc_ct *ct)
>  {
>  	struct intel_guc *guc = ct_to_guc(ct);
> -	u32 base, cmds, size;
> +	u32 base, cmds;
>  	int err;
>  	int i;
>  
> @@ -232,10 +258,11 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>  	 */
>  	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
>  		GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
> +
>  		cmds = base + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
> -		size = PAGE_SIZE / 4;
> -		CT_DEBUG(ct, "%d: addr=%#x size=%u\n", i, cmds, size);
> -		guc_ct_buffer_desc_init(ct->ctbs[i].desc, cmds, size);
> +		CT_DEBUG(ct, "%d: cmds addr=%#x\n", i, cmds);
> +
> +		guc_ct_buffer_reset(&ct->ctbs[i], cmds);
>  	}
>  
>  	/*
> @@ -259,7 +286,7 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>  err_deregister:
>  	ct_deregister_buffer(ct, INTEL_GUC_CT_BUFFER_TYPE_RECV);
>  err_out:
> -	CT_PROBE_ERROR(ct, "Failed to open channel (err=%d)\n", err);
> +	CT_PROBE_ERROR(ct, "Failed to enable CTB (%pe)\n", ERR_PTR(err));
>  	return err;
>  }
>  
> @@ -314,7 +341,7 @@ static int ct_write(struct intel_guc_ct *ct,
>  	struct guc_ct_buffer_desc *desc = ctb->desc;
>  	u32 head = desc->head;
>  	u32 tail = desc->tail;
> -	u32 size = desc->size;
> +	u32 size = ctb->size;
>  	u32 used;
>  	u32 header;
>  	u32 *cmds = ctb->cmds;
> @@ -323,7 +350,7 @@ static int ct_write(struct intel_guc_ct *ct,
>  	if (unlikely(desc->is_in_error))
>  		return -EPIPE;
>  
> -	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
> +	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>  		     (tail | head) >= size))
>  		goto corrupted;
>  
> @@ -530,7 +557,7 @@ static int ct_read(struct intel_guc_ct *ct, u32 *data)
>  	struct guc_ct_buffer_desc *desc = ctb->desc;
>  	u32 head = desc->head;
>  	u32 tail = desc->tail;
> -	u32 size = desc->size;
> +	u32 size = ctb->size;
>  	u32 *cmds = ctb->cmds;
>  	s32 available;
>  	unsigned int len;
> @@ -539,7 +566,7 @@ static int ct_read(struct intel_guc_ct *ct, u32 *data)
>  	if (unlikely(desc->is_in_error))
>  		return -EPIPE;
>  
> -	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
> +	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>  		     (tail | head) >= size))
>  		goto corrupted;
>  
> 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 494a51a5200f..4009e2dd0de4 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
> @@ -29,10 +29,12 @@ struct intel_guc;
>   *
>   * @desc: pointer to the buffer descriptor
>   * @cmds: pointer to the commands buffer
> + * @size: size of the commands buffer
>   */
>  struct intel_guc_ct_buffer {
>  	struct guc_ct_buffer_desc *desc;
>  	u32 *cmds;
> +	u32 size;
>  };
>  
>  
> -- 
> 2.28.0
>
Michal Wajdeczko May 25, 2021, 12:48 p.m. UTC | #2 
On 25.05.2021 04:47, Matthew Brost wrote:
> On Thu, May 06, 2021 at 12:13:25PM -0700, Matthew Brost wrote:
>> From: Michal Wajdeczko <michal.wajdeczko@intel.com>
>>
>> In upcoming GuC firmware, CTB size will be removed from the CTB
>> descriptor so we must keep it locally for any calculations.
>>
>> While around, improve some debug messages and helpers.
>>
> 
> desc->size is still used in the patch and really shouldn't be per this

goal of this patch was to start using local ctb->size for any
calculations, not to drop it completely, as at this point (GuC 49)
desc->size is still part of the CTB protocol

> comment but a patch later in the series drops it. Seeing as this patch
> and that patch are going to squashed into a single patch upgrading the
> GuC firmware I think that is ok.

no need to squash this patch

in fact all CTB patches up to and including 20/97 ("drm/i915/guc:
Introduce unified HXG messages") are compatible with current GuC 49.0.1
and IMHO *should* be merged separately

only patches from 21/97 ("drm/i915/guc: Update MMIO based
communication") to 29/97 ("drm/i915/guc: Update firmware to v60.1.2")
must be squashed during merge, as this is were communication protocol is
changing (from GuC 49 to GuC 60) and we may break existing functionality
(HuC authentication)

Michal

> 
> With that:
> Reviewed-by: Matthew Brost <matthew.brost@intel.com> 
> 
>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
>> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>> ---
>>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 55 +++++++++++++++++------
>>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h |  2 +
>>  2 files changed, 43 insertions(+), 14 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 4cc8c0b71699..dbece569fbe4 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> @@ -90,6 +90,24 @@ static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
>>  	desc->owner = CTB_OWNER_HOST;
>>  }
>>  
>> +static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)
>> +{
>> +	guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size);
>> +}
>> +
>> +static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,
>> +			       struct guc_ct_buffer_desc *desc,
>> +			       u32 *cmds, u32 size)
>> +{
>> +	GEM_BUG_ON(size % 4);
>> +
>> +	ctb->desc = desc;
>> +	ctb->cmds = cmds;
>> +	ctb->size = size;
>> +
>> +	guc_ct_buffer_reset(ctb, 0);
>> +}
>> +
>>  static int guc_action_register_ct_buffer(struct intel_guc *guc,
>>  					 u32 desc_addr,
>>  					 u32 type)
>> @@ -148,7 +166,10 @@ static int ct_deregister_buffer(struct intel_guc_ct *ct, u32 type)
>>  int intel_guc_ct_init(struct intel_guc_ct *ct)
>>  {
>>  	struct intel_guc *guc = ct_to_guc(ct);
>> +	struct guc_ct_buffer_desc *desc;
>> +	u32 blob_size;
>>  	void *blob;
>> +	u32 *cmds;
>>  	int err;
>>  	int i;
>>  
>> @@ -176,19 +197,24 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
>>  	 * other code will need updating as well.
>>  	 */
>>  
>> -	err = intel_guc_allocate_and_map_vma(guc, PAGE_SIZE, &ct->vma, &blob);
>> +	blob_size = PAGE_SIZE;
>> +	err = intel_guc_allocate_and_map_vma(guc, blob_size, &ct->vma, &blob);
>>  	if (unlikely(err)) {
>> -		CT_ERROR(ct, "Failed to allocate CT channel (err=%d)\n", err);
>> +		CT_PROBE_ERROR(ct, "Failed to allocate %u for CTB data (%pe)\n",
>> +			       blob_size, ERR_PTR(err));
>>  		return err;
>>  	}
>>  
>> -	CT_DEBUG(ct, "vma base=%#x\n", intel_guc_ggtt_offset(guc, ct->vma));
>> +	CT_DEBUG(ct, "base=%#x size=%u\n", intel_guc_ggtt_offset(guc, ct->vma), blob_size);
>>  
>>  	/* store pointers to desc and cmds */
>>  	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
>>  		GEM_BUG_ON((i !=  CTB_SEND) && (i != CTB_RECV));
>> -		ct->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
>> -		ct->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
>> +
>> +		desc = blob + PAGE_SIZE / 4 * i;
>> +		cmds = blob + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
>> +
>> +		guc_ct_buffer_init(&ct->ctbs[i], desc, cmds, PAGE_SIZE / 4);
>>  	}
>>  
>>  	return 0;
>> @@ -217,7 +243,7 @@ void intel_guc_ct_fini(struct intel_guc_ct *ct)
>>  int intel_guc_ct_enable(struct intel_guc_ct *ct)
>>  {
>>  	struct intel_guc *guc = ct_to_guc(ct);
>> -	u32 base, cmds, size;
>> +	u32 base, cmds;
>>  	int err;
>>  	int i;
>>  
>> @@ -232,10 +258,11 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>>  	 */
>>  	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
>>  		GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
>> +
>>  		cmds = base + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
>> -		size = PAGE_SIZE / 4;
>> -		CT_DEBUG(ct, "%d: addr=%#x size=%u\n", i, cmds, size);
>> -		guc_ct_buffer_desc_init(ct->ctbs[i].desc, cmds, size);
>> +		CT_DEBUG(ct, "%d: cmds addr=%#x\n", i, cmds);
>> +
>> +		guc_ct_buffer_reset(&ct->ctbs[i], cmds);
>>  	}
>>  
>>  	/*
>> @@ -259,7 +286,7 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>>  err_deregister:
>>  	ct_deregister_buffer(ct, INTEL_GUC_CT_BUFFER_TYPE_RECV);
>>  err_out:
>> -	CT_PROBE_ERROR(ct, "Failed to open channel (err=%d)\n", err);
>> +	CT_PROBE_ERROR(ct, "Failed to enable CTB (%pe)\n", ERR_PTR(err));
>>  	return err;
>>  }
>>  
>> @@ -314,7 +341,7 @@ static int ct_write(struct intel_guc_ct *ct,
>>  	struct guc_ct_buffer_desc *desc = ctb->desc;
>>  	u32 head = desc->head;
>>  	u32 tail = desc->tail;
>> -	u32 size = desc->size;
>> +	u32 size = ctb->size;
>>  	u32 used;
>>  	u32 header;
>>  	u32 *cmds = ctb->cmds;
>> @@ -323,7 +350,7 @@ static int ct_write(struct intel_guc_ct *ct,
>>  	if (unlikely(desc->is_in_error))
>>  		return -EPIPE;
>>  
>> -	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
>> +	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>>  		     (tail | head) >= size))
>>  		goto corrupted;
>>  
>> @@ -530,7 +557,7 @@ static int ct_read(struct intel_guc_ct *ct, u32 *data)
>>  	struct guc_ct_buffer_desc *desc = ctb->desc;
>>  	u32 head = desc->head;
>>  	u32 tail = desc->tail;
>> -	u32 size = desc->size;
>> +	u32 size = ctb->size;
>>  	u32 *cmds = ctb->cmds;
>>  	s32 available;
>>  	unsigned int len;
>> @@ -539,7 +566,7 @@ static int ct_read(struct intel_guc_ct *ct, u32 *data)
>>  	if (unlikely(desc->is_in_error))
>>  		return -EPIPE;
>>  
>> -	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
>> +	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>>  		     (tail | head) >= size))
>>  		goto corrupted;
>>  
>> 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 494a51a5200f..4009e2dd0de4 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> @@ -29,10 +29,12 @@ struct intel_guc;
>>   *
>>   * @desc: pointer to the buffer descriptor
>>   * @cmds: pointer to the commands buffer
>> + * @size: size of the commands buffer
>>   */
>>  struct intel_guc_ct_buffer {
>>  	struct guc_ct_buffer_desc *desc;
>>  	u32 *cmds;
>> +	u32 size;
>>  };
>>  
>>  
>> -- 
>> 2.28.0
>>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
diff mbox series

Patch

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 4cc8c0b71699..dbece569fbe4 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -90,6 +90,24 @@  static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
 	desc->owner = CTB_OWNER_HOST;
 }
 
+static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)
+{
+	guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size);
+}
+
+static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,
+			       struct guc_ct_buffer_desc *desc,
+			       u32 *cmds, u32 size)
+{
+	GEM_BUG_ON(size % 4);
+
+	ctb->desc = desc;
+	ctb->cmds = cmds;
+	ctb->size = size;
+
+	guc_ct_buffer_reset(ctb, 0);
+}
+
 static int guc_action_register_ct_buffer(struct intel_guc *guc,
 					 u32 desc_addr,
 					 u32 type)
@@ -148,7 +166,10 @@  static int ct_deregister_buffer(struct intel_guc_ct *ct, u32 type)
 int intel_guc_ct_init(struct intel_guc_ct *ct)
 {
 	struct intel_guc *guc = ct_to_guc(ct);
+	struct guc_ct_buffer_desc *desc;
+	u32 blob_size;
 	void *blob;
+	u32 *cmds;
 	int err;
 	int i;
 
@@ -176,19 +197,24 @@  int intel_guc_ct_init(struct intel_guc_ct *ct)
 	 * other code will need updating as well.
 	 */
 
-	err = intel_guc_allocate_and_map_vma(guc, PAGE_SIZE, &ct->vma, &blob);
+	blob_size = PAGE_SIZE;
+	err = intel_guc_allocate_and_map_vma(guc, blob_size, &ct->vma, &blob);
 	if (unlikely(err)) {
-		CT_ERROR(ct, "Failed to allocate CT channel (err=%d)\n", err);
+		CT_PROBE_ERROR(ct, "Failed to allocate %u for CTB data (%pe)\n",
+			       blob_size, ERR_PTR(err));
 		return err;
 	}
 
-	CT_DEBUG(ct, "vma base=%#x\n", intel_guc_ggtt_offset(guc, ct->vma));
+	CT_DEBUG(ct, "base=%#x size=%u\n", intel_guc_ggtt_offset(guc, ct->vma), blob_size);
 
 	/* store pointers to desc and cmds */
 	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
 		GEM_BUG_ON((i !=  CTB_SEND) && (i != CTB_RECV));
-		ct->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
-		ct->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
+
+		desc = blob + PAGE_SIZE / 4 * i;
+		cmds = blob + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
+
+		guc_ct_buffer_init(&ct->ctbs[i], desc, cmds, PAGE_SIZE / 4);
 	}
 
 	return 0;
@@ -217,7 +243,7 @@  void intel_guc_ct_fini(struct intel_guc_ct *ct)
 int intel_guc_ct_enable(struct intel_guc_ct *ct)
 {
 	struct intel_guc *guc = ct_to_guc(ct);
-	u32 base, cmds, size;
+	u32 base, cmds;
 	int err;
 	int i;
 
@@ -232,10 +258,11 @@  int intel_guc_ct_enable(struct intel_guc_ct *ct)
 	 */
 	for (i = 0; i < ARRAY_SIZE(ct->ctbs); i++) {
 		GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
+
 		cmds = base + PAGE_SIZE / 4 * i + PAGE_SIZE / 2;
-		size = PAGE_SIZE / 4;
-		CT_DEBUG(ct, "%d: addr=%#x size=%u\n", i, cmds, size);
-		guc_ct_buffer_desc_init(ct->ctbs[i].desc, cmds, size);
+		CT_DEBUG(ct, "%d: cmds addr=%#x\n", i, cmds);
+
+		guc_ct_buffer_reset(&ct->ctbs[i], cmds);
 	}
 
 	/*
@@ -259,7 +286,7 @@  int intel_guc_ct_enable(struct intel_guc_ct *ct)
 err_deregister:
 	ct_deregister_buffer(ct, INTEL_GUC_CT_BUFFER_TYPE_RECV);
 err_out:
-	CT_PROBE_ERROR(ct, "Failed to open channel (err=%d)\n", err);
+	CT_PROBE_ERROR(ct, "Failed to enable CTB (%pe)\n", ERR_PTR(err));
 	return err;
 }
 
@@ -314,7 +341,7 @@  static int ct_write(struct intel_guc_ct *ct,
 	struct guc_ct_buffer_desc *desc = ctb->desc;
 	u32 head = desc->head;
 	u32 tail = desc->tail;
-	u32 size = desc->size;
+	u32 size = ctb->size;
 	u32 used;
 	u32 header;
 	u32 *cmds = ctb->cmds;
@@ -323,7 +350,7 @@  static int ct_write(struct intel_guc_ct *ct,
 	if (unlikely(desc->is_in_error))
 		return -EPIPE;
 
-	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
+	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
 		     (tail | head) >= size))
 		goto corrupted;
 
@@ -530,7 +557,7 @@  static int ct_read(struct intel_guc_ct *ct, u32 *data)
 	struct guc_ct_buffer_desc *desc = ctb->desc;
 	u32 head = desc->head;
 	u32 tail = desc->tail;
-	u32 size = desc->size;
+	u32 size = ctb->size;
 	u32 *cmds = ctb->cmds;
 	s32 available;
 	unsigned int len;
@@ -539,7 +566,7 @@  static int ct_read(struct intel_guc_ct *ct, u32 *data)
 	if (unlikely(desc->is_in_error))
 		return -EPIPE;
 
-	if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
+	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
 		     (tail | head) >= size))
 		goto corrupted;
 
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 494a51a5200f..4009e2dd0de4 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
@@ -29,10 +29,12 @@  struct intel_guc;
  *
  * @desc: pointer to the buffer descriptor
  * @cmds: pointer to the commands buffer
+ * @size: size of the commands buffer
  */
 struct intel_guc_ct_buffer {
 	struct guc_ct_buffer_desc *desc;
 	u32 *cmds;
+	u32 size;
 };