drm/msm/dpu: limit writeback modes according to max_linewidth

Writeback modes were being added according to mode_config.max_width
but this is assigned to double of max_mixer_width.

For compositors/clients using a single SSPP, this will fail
the dpu_plane's atomic check as it checks for max_linewidth.

Limit writeback modes according to max_linewidth to allow
even compositors/clients which use only a single SSPP to
use writeback.

Fixes: 77b001acdcfeb ("drm/msm/dpu: add the writeback connector layer")
Reported-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Jessica Zhang <quic_jesszhan@quicinc.com> # Trogdor (SC8170)
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/486176/
Link: https://lore.kernel.org/r/20220513225959.19004-1-quic_abhinavk@quicinc.com
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
index 7620ffe557796482d78c4f4adf20c10e0d4d995a..399115e4e217f7b279b35f8bc0ba0aba8fee72fa 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
@@ -8,8 +8,10 @@
 static int dpu_wb_conn_get_modes(struct drm_connector *connector)
 {
        struct drm_device *dev = connector->dev;
+       struct msm_drm_private *priv = dev->dev_private;
+       struct dpu_kms *dpu_kms = to_dpu_kms(priv->kms);
 
-       return drm_add_modes_noedid(connector, dev->mode_config.max_width,
+       return drm_add_modes_noedid(connector, dpu_kms->catalog->caps->max_linewidth,
                        dev->mode_config.max_height);
 }