Hi Tomi & Laurent,

On Tue, Apr 02, 2019 at 06:55:08PM +0300, Laurent Pinchart wrote:
> On Tue, Apr 02, 2019 at 06:36:21PM +0300, Tomi Valkeinen wrote:
> > On 21/11/2018 18:09, Sebastian Reichel wrote:
> > > Hi,
> > > 
> > > Here is another round of the DSI command mode panel patchset
> > > integrating the feedback from PATCHv4. The patches are based
> > > on 4.20-rc1 + fixes from Laurent and Tony. I dropped the patches
> > > for OMAP3 support (it needs a workaround for a hardware bug) and
> > > for automatic display rotation. They should get their own series,
> > > once this patchset has landed.
> > 
> > The big omapdrm bridge/panel series from Laurent has been merged to
> > drm-next. I think this series can now be rebased and merged.
> > 
> > However, all this needs to be changed to DRM bridge/panel model sooner
> > or later (sooner, please!), but perhaps it's best to first go with the
> > legacy way.
> 
> I would be OK with that, but I'd like to understand what we still need
> to do to convert DSI support to DRM bridge and panel. Sebastian, if
> you've looked into it, could you provide some insight ?

I have a rebased & tested version of the patches getting the Droid 4
panel working in this branch (together with 2 patches adding
backlight support for testing purposes). I will send it as a patch
series in a few minutes.

https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-n900.git/log/?h=omapdrm-5.2-with-dsi

I also had a look at converting to DRM bridge/panel model and
started working on it in the following branch. It's completley
untested and probably not working at all. Also the most recent
patches are not yet properly splitted / formated. But they show
my idea of how this can be achieved:

1. Add DSI transfer() function
2. Convert custom functions to use transfer() instead
3. Convert to use mipi_dsi_host
4. Get rid of custom DSI related omapdss functions
5. at this point panel conversion can hopefully happen the
   same way as for the other modules

https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-n900.git/log/?h=omapdrm-5.2-with-dsi-untested-work-branch

P.S.: I will continue to work on this, but probably not in
the next 4 weeks. I'm currently very busy with non-kernel
tasks and still have to review > 200 power-supply patches.

-- Sebastian