Fix several bugs, possibly causing image corruption when using UBWC with
the drm/msm driver.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
Dmitry Baryshkov (4):
      drm/msm/mdss: correct HBB programmed on UBWC 5.x and 6.x devices
      drm/msm/dpu: offset HBB values written to DPU by -13
      drm/msm/dpu: program correct register for UBWC config on DPU 8.x+
      drm/msm/dpu: fix SSPP_UBWC_STATIC_CTRL programming on UBWC 5.x+

 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c | 55 +++++++++++++++++------------
 drivers/gpu/drm/msm/msm_mdss.c              |  2 +-
 2 files changed, 33 insertions(+), 24 deletions(-)
---
base-commit: b775e489bec70895b7ef6b66927886bbac79598f
change-id: 20260117-msm-ubwc-fixes-350f67d860d5

Best regards,
-- 
With best wishes
Dmitry

On 1/17/26 3:35 AM, Dmitry Baryshkov wrote:

> Fix several bugs, possibly causing image corruption when using UBWC with
> the drm/msm driver.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
> Dmitry Baryshkov (4):
>        drm/msm/mdss: correct HBB programmed on UBWC 5.x and 6.x devices
>        drm/msm/dpu: offset HBB values written to DPU by -13
>        drm/msm/dpu: program correct register for UBWC config on DPU 8.x+
>        drm/msm/dpu: fix SSPP_UBWC_STATIC_CTRL programming on UBWC 5.x+

Thanks, seems to fix the 
https://gitlab.freedesktop.org/drm/msm/-/issues/79 issue for me:

- disabled the workaround (`debug { disable-direct-scanout }` in Niri's 
config) i.e. enabled direct scanout
- opened System Shock Remake in full screen on the external 3840x2560@60 
monitor
- everything looks fine, the right half of the screen does not show any 
alpha artifacts


Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455


~val