[RFC PATCH 17/97] drm/i915/guc: Stop using mutex while sending CTB messages

[Matthew Brost]

On Thu, May 06, 2021 at 12:13:31PM -0700, Matthew Brost wrote:
> From: Michal Wajdeczko <michal.wajdeczko at intel.com>
> 
> We are no longer using descriptor to hold G2H replies and we are
> protecting access to the descriptor and command buffer by the
> separate spinlock, so we can stop using mutex.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>

Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> ---
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 4 ----
>  1 file changed, 4 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 bee0958d8bae..cb58fa7f970c 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> @@ -537,7 +537,6 @@ static int ct_send(struct intel_guc_ct *ct,
>  int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len,
>  		      u32 *response_buf, u32 response_buf_size)
>  {
> -	struct intel_guc *guc = ct_to_guc(ct);
>  	u32 status = ~0; /* undefined */
>  	int ret;
>  
> @@ -546,8 +545,6 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len,
>  		return -ENODEV;
>  	}
>  
> -	mutex_lock(&guc->send_mutex);
> -
>  	ret = ct_send(ct, action, len, response_buf, response_buf_size, &status);
>  	if (unlikely(ret < 0)) {
>  		CT_ERROR(ct, "Sending action %#x failed (err=%d status=%#X)\n",
> @@ -557,7 +554,6 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len,
>  			 action[0], ret, ret);
>  	}
>  
> -	mutex_unlock(&guc->send_mutex);
>  	return ret;
>  }
>  
> -- 
> 2.28.0
>