[Letux-kernel] module_mipi_dsi_driver panel with omapdrm?

[H. Nikolaus Schaller]

Hi Laurent,

> Am 24.07.2020 um 03:24 schrieb Laurent Pinchart <laurent.pinchart at ideasonboard.com>:
> 
> Hi Nikolaus,
> 
> On Thu, Jul 23, 2020 at 09:03:49AM +0200, H. Nikolaus Schaller wrote:
>>> Am 08.07.2020 um 09:52 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>>>> Am 07.07.2020 um 21:04 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>>>> 
>>>> And what I would need to know before I start to write new code is
>>>> if is possible to operate a video mipi dsi panel with driver from
>>>> gpu/drm/panel together with omapdrm (v5.7 and later).
>>> 
>>> I did a quick test on a 5.7.6 kernel with the sysc fixes as
>>> suggested by Tony.
>>> 
>>> Then I overwrote the compatible entry of our display to be
>>> orisetech,otm8009a and configured to build the otm8009a panel driver.
>>> 
>>> The panel driver is loaded, but not probed (no call to otm8009a_probe).
>>> It is shown in /sys/bus/mipi-dsi/drivers (and lsmod) but not /sys/bus/mipi-dsi/devices.
>>> 
>>> So what should I try next?
>> 
>> Any suggestions if and how it is possible to use a gpu/drm/panel MIPI DSI
>> video mode panel with omapdrm (on OMAP5)?
> 
> For the DSI panel to probe, the display driver needs to register a DSI
> host with mipi_dsi_host_register().

I see.

> omapdrm doesn't do so yet, we need
> to integrate Sebastian's "[PATCHv2 00/56] drm/omap: Convert DSI code to
> use drm_mipi_dsi and drm_panel" series first. I'll try to review it in
> the near future.
> 
>> The problem is that our old omapdrm/display driver is broken since v5.7 and
>> an experimental gpu/drm/panel driver does not probe. And I assume that
>> omapdrm/display will disappear completely soon.
> 
> Not before Sebastian's series gets integrated.

Yes, it is be very important for us since I do not want to find out why the
old omapdrm/display driver isn't working any more just to have it rewritten
again and moved to gpu/drm/panel within a very short time frame.

I would be happy to start the new panel driver and test it with Sebastian's
series. AFAIR Sebastian's series doesn't currently apply well to v5.8-rc so
it would be nice if there were a work-in-progress repo that is rebased every
now and then.

BR and thanks,
Nikolaus