Stm32mp157 lcd panel-ili9881c fifo underrun

[MWoło.2]

Edited console output - see here for future reference

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Hello,

I encounter a problem with my LCD from Winstar model WF50DTYA3MNG10.

I have a custom board based on STM32MP157 with a display connected to Mipi 2 lanes.

On previous Openstlinux(kirkstone) without optee, the driver and display working well.

After switching to the latest Openstlinux I discover a problem with "ltdc fifo underrun"

root@telemach-somunknown:~# [ 96.350190] weston[1406]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
[ 111.422211] [drm] ltdc fifo underrun: please verify display mode
[ 130.546427] [drm] ltdc fifo underrun: please verify display mode
[ 190.539247] [drm] ltdc fifo underrun: please verify display mode
[ 250.549608] [drm] ltdc fifo underrun: please verify display mode
[ 310.542950] [drm] ltdc fifo underrun: please verify display mode
[ 370.537518] [drm] ltdc fifo underrun: please verify display mode
[ 430.556994] [drm] ltdc fifo underrun: please verify display mode

Initialization seems to be without any errors

[ 0.192213] platform 5a001000.display-controller: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 0.216094] platform 5a001000.display-controller: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 0.216536] platform 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel-WF50DTYA3MNG10@0
[ 0.216606] platform 5a000000.dsi: Fixed dependency cycle(s) with /soc/display-controller@5a001000
[ 3.774088] stm32-display-dsi 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel-WF50DTYA3MNG10@0
[ 3.784610] mipi-dsi 5a000000.dsi.0: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 13.960086] mipi-dsi 5a000000.dsi.0: deferred probe pending

The driver is the same as the previous distro with some small alignment to the latest kernel.

Display show 

According to the log suggestion, I try to apply different modes

now I check 

.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS,

but the screen always looks as in the attached image.

I think that's not display setting a problem but probably the kernel.

What can I do with such an issue?

BR MW

[MWoło.2 · Accepted solution]

I've got an answer. It's simply the wrong clock configured in STMCubeMX(missing CLK_DSI_DSIPLL in st,clksrc). I checked again, set it correctly and now it's working as expected.

The topic can be closed.

BR

Michal