[PATCH v2 14/20] drm/msm/dp: Clear stale MSA colorimetry bits

Xilin Wu sophon at radxa.com
Thu Oct 8 20:16:06 PDT 2026


The MISC0 update clears the bit-depth field but only ORs in the new
colorimetry value. Bits from the previous stream can therefore survive
when the new value clears them.

Clear the colorimetry field together with the bit-depth field before
programming the new stream.

Assisted-by: LLM
Signed-off-by: Xilin Wu <sophon at radxa.com>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 791bb3af2cad..783cafb22374 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -476,7 +476,8 @@ static void msm_dp_ctrl_config_misc1_misc0(struct msm_dp_ctrl_private *ctrl,
 	misc_val = msm_dp_read_link(ctrl, REG_DP_MISC1_MISC0);
 
 	/* clear bpp bits */
-	misc_val &= ~(0x07 << DP_MISC0_TEST_BITS_DEPTH_SHIFT);
+	misc_val &= ~((0x07 << DP_MISC0_TEST_BITS_DEPTH_SHIFT) |
+		      GENMASK(4, 1));
 	misc_val |= colorimetry_cfg << DP_MISC0_COLORIMETRY_CFG_SHIFT;
 	misc_val |= test_bits_depth << DP_MISC0_TEST_BITS_DEPTH_SHIFT;
 	/* Configure clock to synchronous mode */

-- 
2.56.0




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