Patch "drm/msm/dpu: Always flush the slave INTF on the CTL" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/msm/dpu: Always flush the slave INTF on the CTL

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-msm-dpu-always-flush-the-slave-intf-on-the-ctl.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1402e2f5b0b7c6c68abc3b221be0b7cd557bc647
Author: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Date:   Wed Apr 17 01:57:43 2024 +0200

    drm/msm/dpu: Always flush the slave INTF on the CTL
    
    [ Upstream commit 2b938c3ab0a69ec6ea587bbf6fc2aec3db4a8736 ]
    
    As we can clearly see in a downstream kernel [1], flushing the slave INTF
    is skipped /only if/ the PPSPLIT topology is active.
    
    However, when DPU was originally submitted to mainline PPSPLIT was no
    longer part of it (seems to have been ripped out before submission), but
    this clause was incorrectly ported from the original SDE driver.  Given
    that there is no support for PPSPLIT (currently), flushing the slave
    INTF should /never/ be skipped (as the `if (ppsplit && !master) goto
    skip;` clause downstream never becomes true).
    
    [1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_cmd.c?ref_type=heads#L1131-1139
    
    Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
    Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
    Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Patchwork: https://patchwork.freedesktop.org/patch/589901/
    Link: https://lore.kernel.org/r/20240417-drm-msm-initial-dualpipe-dsc-fixes-v1-3-78ae3ee9a697@xxxxxxxxxxxxxx
    Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index aa01698d6b256..a05276f0d6982 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -441,9 +441,6 @@ static void dpu_encoder_phys_cmd_enable_helper(
 
 	_dpu_encoder_phys_cmd_pingpong_config(phys_enc);
 
-	if (!dpu_encoder_phys_cmd_is_master(phys_enc))
-		return;
-
 	ctl = phys_enc->hw_ctl;
 	ctl->ops.update_pending_flush_intf(ctl, phys_enc->intf_idx);
 }