resolution issue

[Dhoti Walla]

Hi,

I have a Pandaboard ES running Ubuntu 11.10. When I connect to a HDMI
monitor with a resolution of 1920x1080 it works fine.

When I connect to a HDMI monitor with a resolution of 1366x768 there is
no display.

But if I first connect the 1920x1080 display, boot the Pandaboard then
switch the HDMI cable to the 1366x768 monitor, the latter works fine.

What can I do to get the 1366x768 HDMI monitor to work directly?

thanks for your help
Dhoti

[Linux777]

> What can I do to get the 1366x768 HDMI monitor to work directly?

Did you tried this?

http://omappedia.org/wiki/PandaBoard_FAQ#How_do_I_set_the_resolution_for_my_Screen.3F

omapfb.mode=dvi:1280x1024MR-24@60

[pavel sadowsky]

Dhoti,

I think the screen detection does not work properly during boot. Did
you check why your second monitor is blanking? Maybe the Omap driver
sets the resolution too high, as in my case? You could also check my
bug in Launchpad, and mark the "This bug affects you" if you think you
have the same problem:
https://bugs.launchpad.net/ubuntu/+source/linux-meta-ti-omap4/+bug/964901

@Linux777: I tried with various bootargs - they did not show any
effect in my case. What worked though was directly writing the timing
into sysfs as shown here:
http://omappedia.org/wiki/Bootargs_for_enabling_display#How_to_read_and_set_EDID_timings_for_HDMI

[Dhoti Walla]

Thank you, this is very helpful information.

Dhoti

[pavel sadowsky]

> this is very helpful information.

Dhoti, did you succeed with the bootargs on Ubuntu 11.10? And, do you
use the HDMI connector next to the USB ports (P2) or the other one
(P1)?

[Linux777-Russia/Moscow]

> @Linux777: I tried with various bootargs - they did not show any
> effect in my case. What worked though was directly writing the timing

> into sysfs as shown here:http://omappedia.org/wiki/Bootargs_for_enabling_display#How_to_read_a...

it's probably because of you're changed bootargs on FAT32 partition,
but how about ext* partition? I'm not sure that ubuntu getting it's
bootargs from FAT32 and not from ext* in /boot...

Anyway please post "more /proc/cmdline" output to ensure - this will
show you the truth about your bootargs ^_^

[pavel sadowsky]

Thanks for the hint. I vaguely remember that I had checked /proc/
cmdline, but I'll double-check and play some more with various
options. But the EDID detection of the graphics driver at boot is
definitely broken.

[dmitry pervushin]

On 04/18/2012 06:48 PM, Linux777-Russia/Moscow wrote:
>> @Linux777: I tried with various bootargs - they did not show any
>> effect in my case. What worked though was directly writing the timing
>> into sysfs as shown here:http://omappedia.org/wiki/Bootargs_for_enabling_display#How_to_read_a...
>
> it's probably because of you're changed bootargs on FAT32 partition,
> but how about ext* partition? I'm not sure that ubuntu getting it's
> bootargs from FAT32 and not from ext* in /boot...

Just FYI - there is how-to about editing bootargs:
http://www.omappedia.com/wiki/PandaBoard_FAQ#How_do_I_saveenv_for_boot_args_on_a_PandaBoard.3F
They are loaded from boot.scr from the 1st (FAT) partition.

Taking the /boot/boot.script from ext2 partition as a starting point is
a good way to go :)

> Anyway please post "more /proc/cmdline" output to ensure - this will
> show you the truth about your bootargs ^_^

--
Sincerely yours,
dmitry pervushin

Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve Loubet. 036 420 040 R.C.S Antibes. Capital de EUR 753.920

[Dhoti Walla]

I have not yet tried out your suggestions coz I had to move to another project. I will be moving back to pandaboard on Monday and will let  you know how it goes. I'm using the HDMI next to the USB.

thanks
Dhoti

[aaron visser]

Dhoti Walla <dhotiwalla@...> writes:

>
>
> I have not yet tried out your suggestions coz I had to move to another
> project. I will be moving back to pandaboard on Monday and will let 
> you know how it goes. I'm using the HDMI next to the USB.
> thanks
> Dhoti
> pavel sadowsky wrote:
>
>

Did you get this working? I'm doing the exact same thing. Changes to the
/boot/boot.script don't seem to help at all.