Re: [PATCH 09/12] drm/i915: Skip intel_crtc_state_dump() if debugs aren't enabled

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 29 Feb 2024, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> On Thu, 15 Feb 2024, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
>> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>
>> intel_crtc_state_dump() does a whole boatload of string formatting
>> which is all wasted energy if the debugs aren't even enabled. Skip
>> the whole thing in that case.
>
> I wonder how something like this would work to skip it in a more generic
> fashion:

In the mean time,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


>
> index 9cc473e5d353..0adc8020ae4f 100644
> --- a/include/drm/drm_print.h
> +++ b/include/drm/drm_print.h
> @@ -206,7 +206,8 @@ drm_vprintf(struct drm_printer *p, const char *fmt, va_list *va)
>  {
>         struct va_format vaf = { .fmt = fmt, .va = va };
>  
> -       p->printfn(p, &vaf);
> +       if (p->printfn)
> +               p->printfn(p, &vaf);
>  }
>  
>  /**
> @@ -330,7 +331,7 @@ static inline struct drm_printer drm_dbg_printer(struct drm_device *drm,
>                                                  const char *prefix)
>  {
>         struct drm_printer p = {
> -               .printfn = __drm_printfn_dbg,
> +               .printfn = drm_debug_enabled(category) ? __drm_printfn_dbg : NULL,
>                 .arg = drm,
>                 .prefix = prefix,
>                 .category = category,
>
>>
>> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_crtc_state_dump.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_crtc_state_dump.c b/drivers/gpu/drm/i915/display/intel_crtc_state_dump.c
>> index b5b9b99213cf..cd78c200d483 100644
>> --- a/drivers/gpu/drm/i915/display/intel_crtc_state_dump.c
>> +++ b/drivers/gpu/drm/i915/display/intel_crtc_state_dump.c
>> @@ -192,6 +192,9 @@ void intel_crtc_state_dump(const struct intel_crtc_state *pipe_config,
>>  	char buf[64];
>>  	int i;
>>  
>> +	if (!drm_debug_enabled(DRM_UT_KMS))
>> +		return;
>> +
>>  	p = drm_dbg_printer(&i915->drm, DRM_UT_KMS, NULL);
>>  
>>  	drm_printf(&p, "[CRTC:%d:%s] enable: %s [%s]\n",

-- 
Jani Nikula, Intel