Re: [Intel-gfx] [PATCH] drm/i915: Reject 5k on HDR planes for planar fb formats

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Nov 18, 2021 at 11:55:16AM +0530, Vidya Srinivas wrote:
> PLANE_CUS_CTL has a restriction of 4096 width even though
> PLANE_SIZE and scaler size registers supports max 5120.
> Reject 5k on HDR plane for planar formats like NV12
> to let the user space know about it.
> 
> Without this patch, when 5k content is sent on HDR plane
> with NV12 content, FIFO underrun is seen and screen blanks
> out. Issue is seen on both TGL and ADL platforms.
> 
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> Signed-off-by: Yashashvi Shantam <shantam.yashashvi@intel.com>
> ---
>  drivers/gpu/drm/i915/display/skl_scaler.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c b/drivers/gpu/drm/i915/display/skl_scaler.c
> index 37eabeff8197..e2e52f5dca3b 100644
> --- a/drivers/gpu/drm/i915/display/skl_scaler.c
> +++ b/drivers/gpu/drm/i915/display/skl_scaler.c
> @@ -86,6 +86,7 @@ static u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_cosited)
>  #define ICL_MAX_DST_H 4096
>  #define SKL_MIN_YUV_420_SRC_W 16
>  #define SKL_MIN_YUV_420_SRC_H 16
> +#define MAX_CUSCTL_W 4096
>  
>  static int
>  skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> @@ -221,6 +222,14 @@ int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
>  	bool force_detach = !fb || !plane_state->uapi.visible;
>  	bool need_scaler = false;
>  
> +	/* PLANE_CUS_CTL size max 4096 */
> +	if (icl_is_hdr_plane(dev_priv, intel_plane->id) &&
> +	    fb && intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier) &&
> +	    (drm_rect_width(&plane_state->uapi.src) >> 16) > MAX_CUSCTL_W) {
> +		DRM_ERROR("HDR chroma upsampler size exceeds limits\n");
> +		return -EINVAL;
> +	}

Wrong place. Should go into the plane->max_width() hook. There also
seems to be a minimum height requirement for the CUS which we're not
checking either.

> +
>  	/* Pre-gen11 and SDR planes always need a scaler for planar formats. */
>  	if (!icl_is_hdr_plane(dev_priv, intel_plane->id) &&
>  	    fb && intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier))
> -- 
> 2.33.0

-- 
Ville Syrjälä
Intel