topic Ronbo panel broken after Yocto update in i.MX Processors

Ronbo panel broken after Yocto update

oli1 — Fri, 01 Nov 2019 13:32:24 GMT

Hey guys,

We recently updated the Yocto version we use (from 4.9-rocko to 4.14-sumo) and now our display panel just shows a white screen. The driver we're using is identical and the relevant sections of the DTB are the same, the only reason we updated was to fix some issues we were having with the UUU tool. Are there any breaking changes in the drm/display subsystem I'm unaware of?

We're using the iMX8MQ-EVK board.

Kind regards

Oli

Re: Ronbo panel broken after Yocto update

igorpadykov — Fri, 01 Nov 2019 23:49:17 GMT

Hi Oli

one can try to rebuild all image from scratch, use software from source.codeaurora.org/external/imx,

pay attention that uboot also should be changed v.2018.03 for L4.14:

uboot-imx - i.MX U-Boot

Best regards
igor
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Re: Ronbo panel broken after Yocto update

oli1 — Sat, 02 Nov 2019 16:12:44 GMT

Hi Igor,

Thanks for the swift reply.

I can confirm that we are using u-boot v2018.03 and kernel 4.14.98. I also attempted a full clean build. This did not fix our issue.

Kind regards

Oli

Re: Ronbo panel broken after Yocto update

igorpadykov — Sun, 03 Nov 2019 11:57:31 GMT

Hi Oli

L4.14 added filtering unsupported frequencies in "int valid_clocks[]"
nwl-dsi.c\bridge\drm\gpu\drivers - linux-imx - i.MX Linux kernel
It wasn't mentioned in kernel 4.9.88:

nwl-dsi.c\bridge\drm\gpu\drivers - linux-imx - i.MX Linux kernel

One can try workarounds provided on

https://community.nxp.com/thread/513899

Best regards
igor