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

Tomi Valkeinen tomi.valkeinen at ti.com
Wed Dec 19 10:30:03 CET 2018

On 18/12/18 20:09, H. Nikolaus Schaller wrote:

>> Comparing it to the (mostly) working kernel, I found out that the bus
>> flags are again broken. I attached a quick hack patch that seems to fix
>> them, and with that I get a working 400x400 plane, but underflows with
>> full-screen plane.
>> I couldn't quite figure out how to fix the bus-flags correctly, though.
> Hm. For me this patch does not make a difference.
> But I think we are close to a solution.

Ok... Well, the VC stuff works ok for me, as far as I see.

I pushed my hacky test branch to:


It has one additional fix "fix dsi depopulate", which is needed if you
want to unload modules.

The panel r63311 driver probes fine, and can read something via DSI (I
get a proper reply for MIPI_DCS_GET_PIXEL_FORMAT), and everything seems
to be ok.

The only problem with my branch are FIFO underflows. Apparently these
were present on older kernels too, and is probably somehow related to
horizontal blanking. 1080x1920 plane causes underflows, but 1000x1920
does not.

Maybe you can compare your driver to the r63311 driver in my branch
(although the r63311 driver is a total mess =).


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