Re: [PATCH v3] drm/i915/display: Limit scaler count and disable pipe joiner on WCL

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

On Tue, 27 Oct 2026, Vidya Srinivas <vidya.srinivas@intel.com> wrote:
> Pipe joining is not supported in the WCL display configuration.
> Modes that would require joining are rejected, matching the
> 4k 60Hz maximum resolution documented for the platform.
>
> Also, WCL support single pipe scaler instead of two.

One change per patch, please. The changes are functionally unrelated.

> Bspec: 74286

Git commit trailers go together with no blank lines in between...

> v2: Rebase onto latest upstream

...and certainly not the changelog in between. And v3 changes are
missing.

> Suggested-by: Charlton Lin <charlton.lin@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
>  drivers/gpu/drm/i915/display/intel_dp.c             | 4 ++--
>  2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index f17fc2c68472..c74256359c25 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -1813,7 +1813,10 @@ static void __intel_display_device_info_runtime_init(struct intel_display *displ
>  	if (intel_display_wa(display, INTEL_DISPLAY_WA_14011765242))
>  		for_each_pipe(display, pipe)
>  			display_runtime->num_scalers[pipe] = 0;
> -	else if (DISPLAY_VER(display) >= 11) {
> +	else if (DISPLAY_VERx100(display) == 3002) {
> +		for_each_pipe(display, pipe)
> +			display_runtime->num_scalers[pipe] = 1;
> +	} else if (DISPLAY_VER(display) >= 11) {
>  		for_each_pipe(display, pipe)
>  			display_runtime->num_scalers[pipe] = 2;
>  	} else if (DISPLAY_VER(display) >= 9) {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 00e02e019d25..ef164a797618 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
>  			return false;
>  	}
>  
> -	return DISPLAY_VER(display) >= 12 ||
> +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) != 3002) ||
>  		(DISPLAY_VER(display) == 11 &&
> -		 encoder->port != PORT_A);
> +		 encoder->port != PORT_A));
>  }
>  
>  static int dg2_max_source_rate(struct intel_dp *intel_dp)

-- 
Jani Nikula, Intel