Re: [PATCH] drm/xe/guc: Treat non-response message after BUSY as unexpected

[Matthew Brost <matthew.brost@intel.com>]

On Thu, Jan 11, 2024 at 04:48:38PM +0100, Michal Wajdeczko wrote:
> Once GuC replied with GUC_HXG_TYPE_NO_RESPONSE_BUSY message then
> we may expect that only RESPONSE_SUCCESS or FAILURE message will
> be sent, anything else is a violation of the HXG protocol.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>

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

> ---
>  drivers/gpu/drm/xe/xe_guc.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index 6e73ebf67251..254c9d3c8c73 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -718,8 +718,12 @@ int xe_guc_mmio_send_recv(struct xe_guc *guc, const u32 *request,
>  		if (unlikely(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) !=
>  			     GUC_HXG_ORIGIN_GUC))
>  			goto proto;
> -		if (unlikely(ret))
> +		if (unlikely(ret)) {
> +			if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) !=
> +			    GUC_HXG_TYPE_NO_RESPONSE_BUSY)
> +				goto proto;
>  			goto timeout;
> +		}
>  	}
>  
>  	if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) ==
> 
> base-commit: 79184e72263e91528195db01783148435c7e4fad
> -- 
> 2.25.1
>