On 5/13/2022 3:59 PM, Abhinav Kumar wrote:

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

Tested-by: Jessica Zhang quic_jesszhan@quicinc.com # Trogdor (SC8170)

Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com

drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c index 7620ffe55779..399115e4e217 100644 --- 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); }

-- 2.35.1