Re: [Intel-gfx] [PATCH] drm/i915/display: clear plane color control register when turn plane off

["Lee, Shawn C" <shawn.c.lee@intel.com>]

On Wed, August 31, 2022 8:33 PM, Ville Syrjälä wrote:
>On Mon, Aug 01, 2022 at 11:16:16PM +0800, Lee Shawn C wrote:
>> Customer report abnormal display output while switch eDP off sometimes.
>> In current display disable flow, plane will be off at first. Then turn 
>> eDP off and disable HW pipe line. We found the abnormal pixel comes 
>> after turn plane off. Clear plane color ctl register when driver 
>> disable plane can solve this symptom.
>> 
>> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/skl_universal_plane.c | 3 +++
>>  1 file changed, 3 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c 
>> b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> index caa03324a733..90977cfb7ebb 100644
>> --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> @@ -620,6 +620,8 @@ skl_plane_disable_arm(struct intel_plane *plane,
>>  
>>  	intel_de_write_fw(dev_priv, PLANE_CTL(pipe, plane_id), 0);
>>  	intel_de_write_fw(dev_priv, PLANE_SURF(pipe, plane_id), 0);
>> +	if (DISPLAY_VER(dev_priv) >= 10)
>> +		intel_de_write_fw(dev_priv, PLANE_COLOR_CTL(pipe, plane_id), 0);
>>  }
>>  
>>  static void
>> @@ -638,6 +640,7 @@ icl_plane_disable_arm(struct intel_plane *plane,
>>  	intel_psr2_disable_plane_sel_fetch(plane, crtc_state);
>>  	intel_de_write_fw(dev_priv, PLANE_CTL(pipe, plane_id), 0);
>>  	intel_de_write_fw(dev_priv, PLANE_SURF(pipe, plane_id), 0);
>> +	intel_de_write_fw(dev_priv, PLANE_COLOR_CTL(pipe, plane_id), 0);
>
>This makes no sense. The register value shouldn't even get latched since you wrote the arming register (PLANE_SURF) before this one.
>
>What platform is the problematic machine?
>

ADL-P

Best regards,
Shawn

>>  }
>>  
>>  static bool
>> --
>> 2.17.1
>
>--
>Ville Syrjälä
>Intel