[Intel-gfx] [PATCH 2/2] drm/i915: Tune down MCH_SSKPD values warning

[Paulo Zanoni]

2014-08-04 12:03 GMT-03:00 Ville Syrjälä <ville.syrjala at linux.intel.com>:
> On Mon, Aug 04, 2014 at 11:18:28AM +0200, Daniel Vetter wrote:
>> Users often can't do anything about this since their vendors stopped
>> providing BIOS updates. Also we seem to be able to hack around it
>> with increased latency values, and thus far the only reports have
>> been for screens with really high resolutions. So tune it down to a
>> level where only developers can see it.
>>
>> Also drop some of the end-user fluff.
>>
>> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>
> Both patches make sense to me so:
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

I never really understood why we expect a specific value for a
specific field of the SSKPD on SNB. Isn't this value based on a lot of
different machine-dependent variables? On HSW this doesn't make sense
at all (and we don't have this check there, so the code is already
fine).

>
>> ---
>>  drivers/gpu/drm/i915/intel_pm.c | 8 +++-----
>>  1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index 4f879494e0c5..684dc5f60544 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -5235,11 +5235,9 @@ static void gen6_check_mch_setup(struct drm_device *dev)
>>       uint32_t tmp;
>>
>>       tmp = I915_READ(MCH_SSKPD);
>> -     if ((tmp & MCH_SSKPD_WM0_MASK) != MCH_SSKPD_WM0_VAL) {
>> -             DRM_INFO("Wrong MCH_SSKPD value: 0x%08x\n", tmp);
>> -             DRM_INFO("This can cause pipe underruns and display issues.\n");
>> -             DRM_INFO("Please upgrade your BIOS to fix this.\n");
>> -     }
>> +     if ((tmp & MCH_SSKPD_WM0_MASK) != MCH_SSKPD_WM0_VAL)
>> +             DRM_DEBUG_KMS("Wrong MCH_SSKPD value: 0x%08x This can cause underruns.\n",
>> +                           tmp);
>>  }
>>
>>  static void gen6_init_clock_gating(struct drm_device *dev)
>> --
>> 2.0.1
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Ville Syrjälä
> Intel OTC
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-- 
Paulo Zanoni