[Intel-gfx] [PATCH] drm/i915/skl: Bypass debug message if scalers are not requested

[Tvrtko Ursulin]

On 08/05/2015 03:19 PM, Tvrtko Ursulin wrote:
[snip]
>>>>> Atomic is really complicated, but doing fully diagnostics for each
>>>>> frame
>>>>> is also way too noisy. For that reason we've add a DRM_DEBUG_ATOMIC
>>>>> which
>>>>> can be used for all these state tracking debug lines.
>>>>
>>>> We didn't do anything here and I just noticed kernel is still too
>>>> spammy
>>>> with regards to this issue.
>>>>
>>>> Should we just merge my patch? Still looks completely safe to me...
>>>
>>> doesn't seem to apply any more:(
>>
>> Yeah only some months have passed, who would have thought. :)
>>
>> But I realized that would be only one of the three log lines per cursor
>> update - there is a code path calling skl_detach_scaler two times as
>> well. Looks like this overall, per update:
>>
>> [drm:intel_atomic_setup_scalers] crtc_state = ffff880074b55c00 need = 0
>> avail = 2 scaler_users = 0x0
>> [drm:skl_detach_scaler] CRTC:21 Disabled scaler id 0.0
>> [drm:skl_detach_scaler] CRTC:21 Disabled scaler id 0.1
>>
>> I'll rebase this patch for a start.
>
> Sent it as a new thread but forgot v2 in the subject.
>
> Other source of spam is probably intel_begin_crtc_commit ->
> skl_detach_scalers.
>
> Don't know what the right fix would be there. Looks like it is not
> tracking transitions in scaler use so it would be able to act and log
> when something interesting happens, but rather does it every time. I
> defer to Chandra. :)

Ok I've sent something named "[PATCH] drm/i915/skl: Only disable scalers 
once".

It was only compile tested due my current lack of suitable hardware for 
testing. And I don't pretend to be confident in the world of atomic 
states etc. so it may well be completely wrong.

So either scrutinize it a lot please, or let it be a motivator to come 
up with a proper fix of your own. :)

Regards,

Tvrtko