[Letux-kernel] OMAP5: inconsistency between target-module and dsi_of_data_omap5

H. Nikolaus Schaller hns at goldelico.com
Mon Jul 6 18:10:49 CEST 2020

Hi Tony,

> Am 06.07.2020 um 16:36 schrieb Tony Lindgren <tony at atomide.com>:
> * H. Nikolaus Schaller <hns at goldelico.com> [200705 15:41]:
>> Does the panel driver also need some modification? It is no longer loaded.
> Hmm so what's the panel driver in this case?


> I think you should now be using just the generic panel with
> drivers/gpu/drm/panel/panel-simple or some panel specific
> driver for dsi.

None of them supports the vendor specific MIPI commands of
this panel.

Therefore we have our own panel driver for years and try to
keep pace with upstream changes.

> I think dsi command mode is now the only omapdrm output not
> yet using generic panel. And Sebastian has a branch pending
> for updating dsi command mode to use generic panel.

I know and had made an attempt to make a modified panel driver
compatible to his code.

But his code is no longer compatible to v5.7 or v5.8 and I failed
to get the panel working on earlier releases.

We also use it in video mode and not command mode.

It seems to be the third or fourth time that we have to rework
the panel driver for an -rc1 because dss panel api has changed
(for good reasons)...

The best thing would be that the panel driver can be upstreamed.
Ideally as a DRM panel and no an OMAPDSS display.

But there are some blocking points:

a) driver is now no longer working, so that it is no longer ready
   for submission
b) there is no DTS upstream that makes use of it
c) it is still an omapdss display driver sitting in
   drivers/gpu/drm/omapdrm/displays where it works up to v5.6.y
d) AFAIR omapdrm does not support random MIPI-DSI panels from
   drivers/gpu/drm/panel (or does it now and we have not yet

Sort of hen&egg problem :)

BR and thanks,

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