Hi Dmitry,
On Fri Mar 13, 2026 at 6:14 PM CET, Dmitry Baryshkov wrote:
> On Fri, Mar 13, 2026 at 09:33:18AM +0100, Luca Weiss wrote:
>> Hi Mahadevan,
>>
>> On Thu Jan 1, 2026 at 6:04 AM CET, Mahadevan P wrote:
>> > On SC7280 targets, display modes with a width greater than the
>> > max_mixer_width (2400) are rejected during mode validation when
>> > merge3d is disabled. This limitation exists because, without a
>> > 3D merge block, two layer mixers cannot be combined(non-DSC interface),
>> > preventing large layers from being split across mixers. As a result,
>> > higher resolution modes cannot be supported.
>> >
>> > Enable merge3d support on SC7280 to allow combining streams from
>> > two layer mixers into a single non-DSC interface. This capability
>> > removes the width restriction and enables buffer sizes beyond the
>> > 2400-pixel limit.
>> >
>> > Fixes: 591e34a091d1 ("drm/msm/disp/dpu1: add support for display for
>> > SC7280 target")
>> > Signed-off-by: Mahadevan P <[email protected]>
>>
>> This patch is causing display regression on QCM6490 fairphone-fp5.
>>
>> With this patch in 7.0-rc3 (or 6.18.16) there's just pink noise on the
>> screen. When reverting this patch everything becomes working again.
>>
>> See also
>> https://salsa.debian.org/Mobian-team/devices/kernels/qcom-linux/-/issues/41
>>
>> @Dmitry: Can we revert this for later 7.0-rc, in case it's not fixed
>> quickly?
>
> Could you please provide the resource allocation parts of
> debugfs/dri/0/state for both working and non-working cases?
Working (patch reverted)
# cat /sys/kernel/debug/dri/1/state
plane[44]: plane-0
crtc=crtc-0
fb=71
allocated by = phoc
refcount=2
format=XR24 little-endian (0x34325258)
modifier=0x500000000000001
size=1224x2700
layers:
size[0]=1224x2700
pitch[0]=5120
offset[0]=0
obj[0]:
name=0
refcount=6
start=00103729
size=14680064
imported=no
crtc-pos=1224x2700+0+0
src-pos=1224.000000x2700.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=1
sspp[0]=sspp_0
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=1224x2700+0+0
dst[0]=1224x2700+0+0
plane[50]: plane-1
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_8
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
plane[56]: plane-2
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_9
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
plane[62]: plane-3
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_10
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
crtc[68]: crtc-0
enable=1
active=1
self_refresh_active=0
planes_changed=1
mode_changed=0
active_changed=0
connectors_changed=0
color_mgmt_changed=0
plane_mask=1
connector_mask=1
encoder_mask=1
mode: "1224x2700": 90 311156 1224 1256 1264 1272 2700 2708 2710 2718
0x48 0x0
lm[0]=2
ctl[0]=0
crtc[69]: crtc-1
enable=0
active=0
self_refresh_active=0
planes_changed=0
mode_changed=0
active_changed=0
connectors_changed=0
color_mgmt_changed=0
plane_mask=0
connector_mask=0
encoder_mask=0
mode: "": 0 0 0 0 0 0 0 0 0 0 0x0 0x0
connector[34]: DSI-1
crtc=crtc-0
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=0
max_requested_bpc=0
colorspace=Default
connector[36]: DP-1
crtc=(null)
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=1
max_requested_bpc=0
colorspace=Default
connector[39]: Writeback-1
crtc=(null)
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=0
max_requested_bpc=0
colorspace=Default
resource mapping:
pingpong=# # 68 # - - - - - - - - -
mixer=# - 68 # - - - -
ctl=68 # # # - - - -
dspp=# - - - - - - -
dsc=68 - - - - - - -
cdm=#
sspp=# - - - - - - - # # # - - - - -
cwb=- - - -
Broken (with the patch)
# cat /sys/kernel/debug/dri/1/state
plane[44]: plane-0
crtc=crtc-0
fb=72
allocated by = phoc
refcount=2
format=XR24 little-endian (0x34325258)
modifier=0x500000000000001
size=1224x2700
layers:
size[0]=1224x2700
pitch[0]=5120
offset[0]=0
obj[0]:
name=0
refcount=6
start=00103729
size=14680064
imported=no
crtc-pos=1224x2700+0+0
src-pos=1224.000000x2700.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=1
sspp[0]=sspp_0
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=1224x2700+0+0
dst[0]=1224x2700+0+0
plane[50]: plane-1
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_8
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
plane[56]: plane-2
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_9
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
plane[62]: plane-3
crtc=(null)
fb=0
crtc-pos=0x0+0+0
src-pos=0.000000x0.000000+0.000000+0.000000
rotation=1
normalized-zpos=0
color-encoding=ITU-R BT.601 YCbCr
color-range=YCbCr limited range
color_mgmt_changed=0
color-pipeline=0
stage=0
sspp[0]=sspp_10
multirect_mode[0]=none
multirect_index[0]=solo
src[0]=0x0+0+0
dst[0]=0x0+0+0
crtc[68]: crtc-0
enable=1
active=1
self_refresh_active=0
planes_changed=1
mode_changed=0
active_changed=0
connectors_changed=0
color_mgmt_changed=0
plane_mask=1
connector_mask=1
encoder_mask=1
mode: "1224x2700": 90 311156 1224 1256 1264 1272 2700 2708 2710 2718
0x48 0x0
lm[0]=2
ctl[0]=0
lm[1]=3
ctl[1]=0
crtc[69]: crtc-1
enable=0
active=0
self_refresh_active=0
planes_changed=0
mode_changed=0
active_changed=0
connectors_changed=0
color_mgmt_changed=0
plane_mask=0
connector_mask=0
encoder_mask=0
mode: "": 0 0 0 0 0 0 0 0 0 0 0x0 0x0
connector[34]: DSI-1
crtc=crtc-0
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=0
max_requested_bpc=0
colorspace=Default
connector[36]: DP-1
crtc=(null)
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=1
max_requested_bpc=0
colorspace=Default
connector[39]: Writeback-1
crtc=(null)
self_refresh_aware=0
interlace_allowed=0
ycbcr_420_allowed=0
max_requested_bpc=0
colorspace=Default
resource mapping:
pingpong=# # 68 68 - - - - - - - - -
mixer=# - 68 68 - - - -
ctl=68 # # # - - - -
dspp=# - - - - - - -
dsc=68 - - - - - - -
cdm=#
sspp=# - - - - - - - # # # - - - - -
cwb=- - - -
