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

[Michel Thierry]

On 1/15/2018 9:15 AM, Tvrtko Ursulin wrote:
> 
> 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:
> 

Thanks. Yes, I did and also compared the error state output 
(intel_error_decode also still works). The only change is that the batch 
/ ring / HWSP sections now use the engine->name (e.g. they will use rcs0 
instead of render, vcs0 instead of bsd, etc.).

I didn't see anything in IGT complaining (probably because IGT usually 
reads dmesg and there we already use engine->name), but there must be 
something else out there that will complain.


> 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);
>>