BBB Ubuntu 14.04.2 July 08 HDMI sync, use Kernel 4.1?

I just updated several BBB Rev C to Ubuntu 14.04.2 July 08 and managed to get a simple Flask demo running, which was pretty cool. Apache 2 was also running and serving the default page. Together, with HTOP, that uses less than 15% CPU and less than 35 MB RAM. Next up: installing a full LAMP stack and trying to get some legacy PHP to run.

I’m using the HDMI output to a variety of monitors, some with HDMI and some with only DVI (for development), and also some HDMI LCD touchscreens (what we ultimately want to use in the final product). I don’t want a GUI desktop; rather we will use the HDMI touchscreen as a user-facing interface for a kiosk and environment control system, all custom programmed to relate to that. The sytems will be otherwise headless and remotely administered.

Higher end DVI monitors such as HP ZR24W (1920x1200), or the older HP LP2065 (1600x1200) synch right up in 1280x1024, so does a 1920x1080 HDMI Acer H226HQL. A DVI Samsung 710TM, native 1280x1024, mostly won’t synch, ever. I plan to look at the serial connection while booting and see if I can force it.

Not all LCD panels synch either. 1280x1024 is not a common resolution, but 1366x768 is, and so is 1280x800.

I’ve been reading the online docs about LCD support, and have bought some breakouts so I can sniff the EDID coming from the monitor and see if I can figure out why some work and some don’t.

Would updating to Kernel 4.1 help or should I stay away due to all the reported 4.1 issues with various peripherals?

Is there a kernel version change log? I went to https://github.com/beagleboard/linux but after some blundering around looking for something to do with releases I did not find anything. For example what are the “pm/cpuidle fixes”, where can I read about them, and might the Kernel 4 have some HDMI related improvements? I’m giving it a go, worst case I can go back to the older kernel…

Thanks for all the great work on this awesome little system!

Bruce Boyes

On Tuesday, July 14, 2015 at 7:04:49 AM UTC-6, RobertCNelson wrote:

I just updated several BBB Rev C to Ubuntu 14.04.2 July 08 and managed to
get a simple Flask demo running, which was pretty cool. Apache 2 was also
running and serving the default page. Together, with HTOP, that uses less
than 15% CPU and less than 35 MB RAM. Next up: installing a full LAMP stack
and trying to get some legacy PHP to run.

I'm using the HDMI output to a variety of monitors, some with HDMI and some
with only DVI (for development), and also some HDMI LCD touchscreens (what
we ultimately want to use in the final product). I don't want a GUI desktop;
rather we will use the HDMI touchscreen as a user-facing interface for a
kiosk and environment control system, all custom programmed to relate to
that. The sytems will be otherwise headless and remotely administered.

Higher end DVI monitors such as HP ZR24W (1920x1200), or the older HP LP2065
(1600x1200) synch right up in 1280x1024, so does a 1920x1080 HDMI Acer
H226HQL. A DVI Samsung 710TM, native 1280x1024, mostly won't synch, ever. I
plan to look at the serial connection while booting and see if I can force
it.

Not all LCD panels synch either. 1280x1024 is not a common resolution, but
1366x768 is, and so is 1280x800.

I've been reading the online docs about LCD support, and have bought some
breakouts so I can sniff the EDID coming from the monitor and see if I can
figure out why some work and some don't.

Would updating to Kernel 4.1 help or should I stay away due to all the
reported 4.1 issues with various peripherals?

You can try... If it doesn't work, it's probally out of range..

Is there a kernel version change log? I went to
https://github.com/beagleboard/linux but after some blundering around
looking for something to do with releases I did not find anything. For
example what are the "pm/cpuidle fixes", where can I read about them, and
might the Kernel 4 have some HDMI related improvements? I'm giving it a go,
worst case I can go back to the older kernel...

Look at the top commit of every tag:
https://github.com/beagleboard/linux/tree/4.1.2-ti-r3

https://github.com/beagleboard/linux/commit/3c34b46918cab4eb5dcc7c42173cb743578dbd23

I post the ti delta:

https://github.com/RobertCNelson/ti-linux-kernel/compare/31ae2ddea8e0ef24a8d952d39f47b82c05c51a45...e70ea0c682ff00986715631783d684bee96ffed1

Which gives you the ti changes in every tag..

As we are using:

http://git.ti.com/gitweb/?p=ti-linux-kernel/ti-linux-kernel.git;a=shortlog;h=refs/heads/ti-linux-4.1.y

You can also follow:

https://github.com/RobertCNelson/ti-linux-kernel-dev/commits/ti-linux-4.1.y

as we sync up with:

http://git.ti.com/gitweb/?p=ti-linux-kernel/ti-linux-kernel.git;a=shortlog;h=refs/heads/ti-linux-4.1.y

and include our patches..

Regards,

> Would updating to Kernel 4.1 help or should I stay away due to all the
> reported 4.1 issues with various peripherals?

You can try... If it doesn't work, it's probally out of range..

What do you mean by "out of range" - the monitor I am trying to use has
some frequency requirement not possible with BBB? Or something else?

Thanks for all the links re: change logs to kernel.

Bruce