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

[Michal Wajdeczko]

On Tue, 09 Jan 2018 20:33:55 +0100, Michel Thierry  
<michel.thierry at intel.com> wrote:

> Instead of using local string names that we will have to keep
> maintaining, use the engine->name directly.
>
> 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>
> ---
>  drivers/gpu/drm/i915/i915_gpu_error.c | 23 ++++++++++-------------
>  1 file changed, 10 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..db95ecacdace 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -34,16 +34,12 @@
> #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 const char *engine_str(struct drm_i915_private *i915, int  
> engine_id)
> +{
> +	if (!i915->engine[engine_id])
> +		return "";

While unlikely, empty string may be misleading, so maybe better we return
"<invalid>" or at least "?" here. Also maybe we can do as part of more
global helper function like

static inline const char* intel_engine_name(struct intel_engine_cs *engine)
{
	return engine ? engine->name : "<invalid>";
}

static inline struct intel_engine_cs *
intel_engine_lookup(struct drm_i915_private *i915, int engine_id)
{
	if (engine_id < 0 || engine_id > I915_MAX_ENGINES)
		return NULL;
	return i915->engine[engine_id];
}

and then

static const char *engine_str(struct drm_i915_private *i915, int engine_id)
{
	return intel_engine_name(intel_engine_lookup(i915, engine_id));
}

> +	else
> +		return i915->engine[engine_id]->name;
>  }
> static const char *tiling_flag(int tiling)
> @@ -345,7 +341,7 @@ 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 ? " " : "");

Hmm, it looks that -1 is allowed/expected as engine_id so proposed
above check in lookup function is mandatory

> -		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 +413,8 @@ 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 +630,7 @@ 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);