As in the previous generations, on UBWC 5.x and 6.x devices the Highest
Bank Bit value should be programmed into the hardware with the offset of
-13.  Correct the value written into the register to prevent
unpredictable results.

Fixes: 227d4ce0b09e ("drm/msm: Offset MDSS HBB value by 13")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_mdss.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_mdss.c b/drivers/gpu/drm/msm/msm_mdss.c
index bf9a33e925ac..910242f5a71f 100644
--- a/drivers/gpu/drm/msm/msm_mdss.c
+++ b/drivers/gpu/drm/msm/msm_mdss.c
@@ -229,7 +229,7 @@ static void msm_mdss_setup_ubwc_dec_50(struct msm_mdss *msm_mdss)
 {
 	const struct qcom_ubwc_cfg_data *data = msm_mdss->mdss_data;
 	u32 value = MDSS_UBWC_STATIC_UBWC_SWIZZLE(data->ubwc_swizzle) |
-		    MDSS_UBWC_STATIC_HIGHEST_BANK_BIT(data->highest_bank_bit);
+		    MDSS_UBWC_STATIC_HIGHEST_BANK_BIT(data->highest_bank_bit - 13);
 
 	if (data->ubwc_bank_spread)
 		value |= MDSS_UBWC_STATIC_UBWC_BANK_SPREAD;

-- 
2.47.3

On 1/19/26 9:14 AM, Dmitry Baryshkov wrote:
> As in the previous generations, on UBWC 5.x and 6.x devices the Highest
> Bank Bit value should be programmed into the hardware with the offset of
> -13.  Correct the value written into the register to prevent
> unpredictable results.
> 
> Fixes: 227d4ce0b09e ("drm/msm: Offset MDSS HBB value by 13")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad