[Intel-gfx] [PATCH v2] drm/i915: Use the engine name directly in the error_state file

[Tvrtko Ursulin]

On 10/01/2018 01:21, Michel Thierry wrote:
> Instead of using local string names that we will have to keep
> maintaining, use the engine->name directly.
> 
> v2: Better invalid engine_id handling, capture_bo will not be able know
> the engine_id and end up with -1 (Michal).
> 
> Suggested-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Michel Thierry <michel.thierry at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_gpu_error.c | 33 ++++++++++++++++++++-------------
>   1 file changed, 20 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 94499c24f279..422e302161e5 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -34,16 +34,22 @@
>   
>   #include "i915_drv.h"
>   
> -static const char *engine_str(int engine)
> -{
> -	switch (engine) {
> -	case RCS: return "render";
> -	case VCS: return "bsd";
> -	case BCS: return "blt";
> -	case VECS: return "vebox";
> -	case VCS2: return "bsd2";
> -	default: return "";
> -	}
> +static inline const char *intel_engine_name(struct intel_engine_cs *engine)
> +{
> +	return engine ? engine->name : "";
> +}
> +
> +static inline struct intel_engine_cs *
> +intel_engine_lookup(struct drm_i915_private *i915, int engine_id)
> +{
> +	if (engine_id < 0 || engine_id >= I915_NUM_ENGINES)
> +		return NULL;
> +	return i915->engine[engine_id];
> +}
> +
> +static const char *engine_str(struct drm_i915_private *i915, int engine_id)
> +{
> +	return intel_engine_name(intel_engine_lookup(i915, engine_id));
>   }

Feels like a bit of an overkill to have three functions to this trivial 
thing but meh. Could also maybe cheat and have engine_id as unsigned int 
and so would only need to check for >= I915_NUM_ENGINES.

Anyway, I peeked in intel_error_decode source and couldn't spot anything 
that looked it would break. You checked it by running it? Assuming you did:

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko

>   
>   static const char *tiling_flag(int tiling)
> @@ -345,7 +351,7 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
>   		err_puts(m, purgeable_flag(err->purgeable));
>   		err_puts(m, err->userptr ? " userptr" : "");
>   		err_puts(m, err->engine != -1 ? " " : "");
> -		err_puts(m, engine_str(err->engine));
> +		err_puts(m, engine_str(m->i915, err->engine));
>   		err_puts(m, i915_cache_level_str(m->i915, err->cache_level));
>   
>   		if (err->name)
> @@ -417,7 +423,8 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
>   {
>   	int n;
>   
> -	err_printf(m, "%s command stream:\n", engine_str(ee->engine_id));
> +	err_printf(m, "%s command stream:\n", engine_str(m->i915,
> +							 ee->engine_id));
>   	err_printf(m, "  IDLE?: %s\n", yesno(ee->idle));
>   	err_printf(m, "  START: 0x%08x\n", ee->start);
>   	err_printf(m, "  HEAD:  0x%08x [0x%08x]\n", ee->head, ee->rq_head);
> @@ -633,7 +640,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>   		if (error->engine[i].hangcheck_stalled &&
>   		    error->engine[i].context.pid) {
>   			err_printf(m, "Active process (on ring %s): %s [%d], score %d\n",
> -				   engine_str(i),
> +				   engine_str(m->i915, i),
>   				   error->engine[i].context.comm,
>   				   error->engine[i].context.pid,
>   				   error->engine[i].context.ban_score);
>