Android 11.12 on pandaboard

Andy Green andy.green at linaro.org
Mon Jan 23 10:21:09 UTC 2012


On 01/23/2012 04:40 PM, Somebody in the thread at some point said:
> Hi all,
> 
> We have both tried all the builds on the pandaboard 4430 but we have
> encountered some problems.
> It seems like those builds are depending on the screen on how they will
> behave.
> 
> The problem at my side is that the display doesn't want to show something.
> I have tried all the builds on my Asus computer screen (HDMI 1920x1080)
> and my Sony Bravia
> <http://store.sony.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&partNumber=KDL40NX700#features>
> (HDMI 1920x1080).
> But every time the screen stayed black. This was all tested with the
> HDMI port to HDMI in the screen.
> 
> At Mark, the builds worked on his tv at 720p (also Sony Bravia but
> older) through HDMI.
> But when he connected the pandaboard from HDMI to DVI (with an
> converter) it started in phone mode with a low resolution.
> 
> We followed the instructions of the links you send to us carefully and
> we can confirm that Android was running.
> 
> Could there be a problem with the EDID protocol in combination with our
> screens? And is there a way to override it when the screen doesn't
> support the EDID protocol?

Yeah there seems to be a race between connector presence detect and edid
fetch, vs when your TV is ready to give edid.  As it stands it seems to
work for most TVs OK.  The problem's exacerbated by hotplug not working
as it should so getting the EDID later is not the same as getting it at
the start.

In 3.3-rc1, Rob Clark has gotten some improved DRM-based stuff building
on Tomi's previous upstream patches so all this is getting better.

For Android, the video stuff is stuck in a 3.0 kernel timewarp.  We have
forwardported the special version of dss and other pieces from 3.0 aosp
kernel to make accelerated graphics work, but that approach means all
the dss pieces are from 3.0 status and are not benefiting from gradual
upstream improvements.

-Andy

-- 
Andy Green | TI Landing Team Leader
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