[PATCH v1] drm/i915/display: Allow port sync on PTL

[PATCH v1] drm/i915/display: Allow port sync on PTL

[Mitul Golani]

Some dual-SST tiled displays exhibit visual corruption on PTL, with
one tile's image vertically shifted or wrapped by a random amount
that changes on every hotplug.

PTL supports port sync, so allow it to be used to avoid these
display issues.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8991
Fixes: 05cffc074938 ("drm/i915/display: Implement Wa_16024710867")
Cc: stable@vger.kernel.org
Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index a46ab5d3d70f..a0aff087fafa 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4629,7 +4629,7 @@ intel_ddi_port_sync_transcoders(const struct intel_crtc_state *ref_crtc_state,
 	 * From, xe3lpd onwards we have defeatured this with reference to
 	 * Wa_16024710867
 	 */
-	if (!IS_DISPLAY_VER(display, 9, 20))
+	if (!IS_DISPLAY_VER(display, 9, 30))
 		return 0;
 
 	if (!intel_crtc_has_type(ref_crtc_state, INTEL_OUTPUT_DP))
-- 
2.48.1

RE: [PATCH v1] drm/i915/display: Allow port sync on PTL

[Kandpal, Suraj]

> Subject: [PATCH v1] drm/i915/display: Allow port sync on PTL
> 
> Some dual-SST tiled displays exhibit visual corruption on PTL, with one tile's
> image vertically shifted or wrapped by a random amount that changes on
> every hotplug.
> 
> PTL supports port sync, so allow it to be used to avoid these display issues.
> 
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8991
> Fixes: 05cffc074938 ("drm/i915/display: Implement Wa_16024710867")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> b/drivers/gpu/drm/i915/display/intel_ddi.c
> index a46ab5d3d70f..a0aff087fafa 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4629,7 +4629,7 @@ intel_ddi_port_sync_transcoders(const struct
> intel_crtc_state *ref_crtc_state,
>  	 * From, xe3lpd onwards we have defeatured this with reference to
>  	 * Wa_16024710867
>  	 */
> -	if (!IS_DISPLAY_VER(display, 9, 20))
> +	if (!IS_DISPLAY_VER(display, 9, 30))

I am guessing you may need to update the above comment too.

Other than that
LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>


>  		return 0;
> 
>  	if (!intel_crtc_has_type(ref_crtc_state, INTEL_OUTPUT_DP))
> --
> 2.48.1

Re: [PATCH v1] drm/i915/display: Allow port sync on PTL

[Thorsten Leemhuis]

On 10/12/26 06:04, Mitul Golani wrote:
> Some dual-SST tiled displays exhibit visual corruption on PTL, with
> one tile's image vertically shifted or wrapped by a random amount
> that changes on every hotplug.
> 
> PTL supports port sync, so allow it to be used to avoid these
> display issues.

Is this fix for a recent regression still in the "to review" list of
anyone, or did it fell through the cracks? Or was this solved meanwhile
and I just missed it?

Ciao, Thorsten

> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8991
> Fixes: 05cffc074938 ("drm/i915/display: Implement Wa_16024710867")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index a46ab5d3d70f..a0aff087fafa 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4629,7 +4629,7 @@ intel_ddi_port_sync_transcoders(const struct intel_crtc_state *ref_crtc_state,
>  	 * From, xe3lpd onwards we have defeatured this with reference to
>  	 * Wa_16024710867
>  	 */
> -	if (!IS_DISPLAY_VER(display, 9, 20))
> +	if (!IS_DISPLAY_VER(display, 9, 30))
>  		return 0;
>  
>  	if (!intel_crtc_has_type(ref_crtc_state, INTEL_OUTPUT_DP))

Re: [PATCH v1] drm/i915/display: Allow port sync on PTL

[Jani Nikula]

On Fri, 30 Oct 2026, Thorsten Leemhuis <regressions@leemhuis.info> wrote:
> On 10/12/26 06:04, Mitul Golani wrote:
>> Some dual-SST tiled displays exhibit visual corruption on PTL, with
>> one tile's image vertically shifted or wrapped by a random amount
>> that changes on every hotplug.
>> 
>> PTL supports port sync, so allow it to be used to avoid these
>> display issues.
>
> Is this fix for a recent regression still in the "to review" list of
> anyone, or did it fell through the cracks? Or was this solved meanwhile
> and I just missed it?

Pushed now, thanks for the reminder.

BR,
Jani.

>
> Ciao, Thorsten
>
>> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8991
>> Fixes: 05cffc074938 ("drm/i915/display: Implement Wa_16024710867")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_ddi.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
>> index a46ab5d3d70f..a0aff087fafa 100644
>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> @@ -4629,7 +4629,7 @@ intel_ddi_port_sync_transcoders(const struct intel_crtc_state *ref_crtc_state,
>>  	 * From, xe3lpd onwards we have defeatured this with reference to
>>  	 * Wa_16024710867
>>  	 */
>> -	if (!IS_DISPLAY_VER(display, 9, 20))
>> +	if (!IS_DISPLAY_VER(display, 9, 30))
>>  		return 0;
>>  
>>  	if (!intel_crtc_has_type(ref_crtc_state, INTEL_OUTPUT_DP))
>

-- 
Jani Nikula, Intel