Not all Line Mixers have corresponding DSPP blocks, which are necessary
for CTM or Gamma Correction. Currently it is possible for CTM-less CRTCs
to get a grip of DSPP-enabled LMs, making it impossible to use CTM (or
GC, once enabled) for other CRTCs. Make sure that RM allocates simpler
LMs first, leaving LMs with attached DSPP for the CRTCs which need them.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
Dmitry Baryshkov (2):
      drm/msm/dpu: correct error messages in RM
      drm/msm/dpu: try reserving the DSPP-less LM first

 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 72 ++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 25 deletions(-)
---
base-commit: b775e489bec70895b7ef6b66927886bbac79598f
change-id: 20260115-dpu-fix-dspp-803dee634153

Best regards,
-- 
With best wishes
Dmitry

On Thu, 15 Jan 2026 22:05:37 +0200, Dmitry Baryshkov wrote:
> Not all Line Mixers have corresponding DSPP blocks, which are necessary
> for CTM or Gamma Correction. Currently it is possible for CTM-less CRTCs
> to get a grip of DSPP-enabled LMs, making it impossible to use CTM (or
> GC, once enabled) for other CRTCs. Make sure that RM allocates simpler
> LMs first, leaving LMs with attached DSPP for the CRTCs which need them.
> 
> 
> [...]

Applied to msm-next, thanks!

[1/2] drm/msm/dpu: correct error messages in RM
      https://gitlab.freedesktop.org/lumag/msm/-/commit/98c8f146f574
[2/2] drm/msm/dpu: try reserving the DSPP-less LM first
      https://gitlab.freedesktop.org/lumag/msm/-/commit/42f62cd79578

Best regards,
-- 
With best wishes
Dmitry