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

[chaegle]

Hello,

I am currently working to integrate the Winstar DF5DSYA3MNG10 display with the STM32MP157C and am running into problems myself.

Any chance you would be willing to share the files you were successful in getting to work?

Thanks,

Cameron