On 18 Jun 04:11 PM, Sebastian Hesselbarth wrote:

On 06/15/2014 05:25 PM, Russell King - ARM Linux wrote:

quoted

As for DT, I should probably state that I'm far from happy with the DT
situation on Dove.  When I've tried it, I've encountered problems with
the HDMI output - the picture spends more time blanked than displaying.
I've no idea what is causing that, I've been through the SI5351
registers, the TDA998x registers, the LCD controller registers, and I
can't find any reason for it.  Yet, boot the same kernel without DT
and it works fine.  Boot back using DT, and it's unstable again.

I can't detect any difference on the actual HDMI signals themselves
either.  The HDMI clock seems stable and of the correct frequency.

There is definitely some difference between booting with DT and booting
with legacy stuff that seems to upset HDMI.

For me, the /only/ reliably working system is one where DT is not
involved.  This means I remain opposed to any solutions which can't
be used in a non-DT environment - at least until the HDMI issue can
be resolved.

Russell,

as said on IRC, I really want this to be sorted out. I prepared a Dove
DT HDMI quick-hack and pushed it to

https://github.com/shesselba/linux-dove.git dove-drm-v3.16-rc1

I can probably give a quick test to this using Qt over FB, or just
plain fb-test / libdrm tests. But you are already doing a more involved
test, so maybe my tests are too simple.

Using your libdrm-armada and xf86-video-armada on Ubuntu raring armhf,
I can run Xfce4 on 1920x1080p60 on Dove Cubox without any blanking
issues. Using xrandr -s <mode> will fail after 2-3 times but that
shouldn't be related to the issues you see.

Please test above branch with kernel config at
https://dl.dropboxusercontent.com/u/59928252/config-dove-v3.16-rc1-hdmi
and report back if issues are still there.

Anyone having a Dove CuBox ready, please also test. Russell has a git
branch for the required video lib and drivers.

Can you point me at those?
-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com