[Letux-kernel] DSI panels with omapdrm on 4.20-rc

Tony Lindgren tony at atomide.com
Mon Nov 12 19:30:21 CET 2018


* H. Nikolaus Schaller <hns at goldelico.com> [181112 17:35]:
> Hi Tomi,
> 4.20-rc1 seems to have broken our DSI panel driver for the OMAP5 Pyra.
> There were some omapdrm API changes which I have tried to fix by inspecting
> panel-dsi-cm.c and also comparing with panel-tpo-td028ttec1.c (which is still working
> on our omap3 systems).
> I also have removed the tiler patches by Matthijs to make sure that
> they do not have an influence.
> The strange thing is that the panel driver module is not even loaded
> during probe time, although we have defined the display alias and not
> changed that compared to 4.19.
> The other strange thing is that I can manually modprobe the driver
> and it is loaded and shown by lsmod, but the probe function is never
> called.
> Any hints what we should check and compare and verify?
> Did the panel driver compatible matching mechanism change for dsi panels
> without a bus (dpi panels are usually loaded as an spi bus client)?
> Or is there a new CONFIG that must be set?

Test with Laurent's fixes, and also looks like Sebastian also has some
recent yet to be posted probe order changes on top of Laurent's fixes
in his linux-n900 branch if Laurent's fixes alone don't help.

Laurent's patches are "[PATCH v3 0/4] omapdrm: Fix runtime PM issues
at module load and unload time" and Sebastian's git tree is at

Adding Laurent and Sebastian to Cc too.



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