From c16f6610ecd85d1bb971a6c1423145adc86565c4 Mon Sep 17 00:00:00 2001
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Sat, 30 Apr 2022 20:55:33 +0300
Subject: drm/msm/dsi: use RMW cycles in dsi_update_dsc_timing
Git-commit: 666a68a70ab76a04869b205dfd33c091ae09adf7
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
The downstream uses read-modify-write for updating command mode
compression registers. Let's follow this approach. This also fixes the
following warning:
drivers/gpu/drm/msm/dsi/dsi_host.c:918:23: warning: variable 'reg_ctrl' set but not used [-Wunused-but-set-variable]
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/484305/
Link: https://lore.kernel.org/r/20220430175533.3817792-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index c983698d1384..a95d5df52653 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -961,10 +961,13 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
reg_ctrl = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL);
reg_ctrl2 = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2);
+ reg_ctrl &= ~0xffff;
reg_ctrl |= reg;
+
+ reg_ctrl2 &= ~DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH__MASK;
reg_ctrl2 |= DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH(bytes_in_slice);
- dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL, reg);
+ dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL, reg_ctrl);
dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2, reg_ctrl2);
} else {
dsi_write(msm_host, REG_DSI_VIDEO_COMPRESSION_MODE_CTRL, reg);
--
2.38.1