Patch "drm/mediatek: dsi: Reduce the time of dsi from LP11 to sending cmd" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    drm/mediatek: dsi: Reduce the time of dsi from LP11 to sending cmd

to the 5.10-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-mediatek-dsi-reduce-the-time-of-dsi-from-lp11-to.patch
and it can be found in the queue-5.10 subdirectory.

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



commit 53e0fe145923916bec209b2a3ed57d10d07a1d1d
Author: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>
Date:   Tue Jan 10 13:54:51 2023 +0800

    drm/mediatek: dsi: Reduce the time of dsi from LP11 to sending cmd
    
    [ Upstream commit 91aeaed2c1147e3b1157dc084d23f190856a6c23 ]
    
    According to Figure 16 Turnaround Procedure on page 36 in [1], you
    can see the status of LP-00 -> LP10 -> LP11. This state can correspond
    to the state of DSI from LP00 -> LP11 in mtk_dsi_lane_ready function
    in mtk_dsi.c.
    
    LP-00 -> LP10 -> LP11 takes about 2*TLPX time (refer to [1] page 51
    to see that TLPX is 50ns)
    
    The delay at the end of the mtk_dsi_lane_ready function should be
    greater than the 2*TLPX specified by the DSI spec, and less than
    the time specified by the DSI_RX (generally 6ms to 40ms), to avoid
    problems caused by the RX specification
    
    [1]:mipi_D-PHY_specification_v1-1
    
    Fixes: 39e8d062b03c ("drm/mediatek: Keep dsi as LP00 before dcs cmds transfer")
    Signed-off-by: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>
    Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
    Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
    Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1673330093-6771-2-git-send-email-xinlei.lee@xxxxxxxxxxxx/
    Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 146c4d04f572d..a6e71b7b69b83 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -704,7 +704,7 @@ static void mtk_dsi_lane_ready(struct mtk_dsi *dsi)
 		mtk_dsi_clk_ulp_mode_leave(dsi);
 		mtk_dsi_lane0_ulp_mode_leave(dsi);
 		mtk_dsi_clk_hs_mode(dsi, 0);
-		msleep(20);
+		usleep_range(1000, 3000);
 		/* The reaction time after pulling up the mipi signal for dsi_rx */
 	}
 }