HDMI out of Range w/ Sakoman build

[Ian]

Hello,

Using a Dell ST2010 LCD display; connected to the HDMI port on my
Panda, and receiving an out of range for the 1600 x 900 @ 60
resolution it defaults to. <-- Is it even possible to support this
resolution? If not, no big deal to get another monitor...

Brought it up on the IRC and was told something would need to be added
to the HDMI driver to enable it; if the Panda can output that rez...

Could someone point me in a direction as to how to patch this, or if
it is possible?

Using a current Sakoman build for my Panda.
This is NOT an issue with the Beagleboard (C4) that I have running a
similar Sakoman build (but for Beagle.)

Thought I would post to the message board so others can benefit from
the results.
Cheers,
Ian

[Steve Sakoman]

On Mon, Dec 6, 2010 at 2:01 PM, Ian <ian.w...@gmail.com> wrote:

> Using a Dell ST2010 LCD display; connected to the HDMI port on my
> Panda, and receiving an out of range for the 1600 x 900 @ 60
> resolution it defaults to. <-- Is it even possible to support this
> resolution? If not, no big deal to get another monitor...

The monitor I typically use is 1920x1080-60, so I don't see why Panda
wouldn't be capable of the lower res 1600x900-60.

It may be that you need to tweak the timings that are used by the
kernel. Your monitor may not like the choices the kernel is making.

> Brought it up on the IRC and was told something would need to be added
> to the HDMI driver to enable it; if the Panda can output that rez...
>
> Could someone point me in a direction as to how to patch this, or if
> it is possible?
>
> Using a current Sakoman build for my Panda.
> This is NOT an issue with the Beagleboard (C4) that I have running a
> similar Sakoman build (but for Beagle.)

So a Beagle using the same monitor doesn't have an issue? Are you
using the default 1024x768 resolution, or have you changed the boot
args to 1600x900-60?

Steve

[Ian Wisbon]

I haven't changed the boot args. Robclark said That particular Res isn't in the HDMI.c driver. And a parse edid shows only that resolution. I will run a few tests and get back to you.

Cheers!
Ian

[Rob Clark]

On Mon, Dec 6, 2010 at 6:30 PM, Steve Sakoman <sak...@gmail.com> wrote:
> On Mon, Dec 6, 2010 at 2:01 PM, Ian <ian.w...@gmail.com> wrote:
>
>> Using a Dell ST2010 LCD display; connected to the HDMI port on my
>> Panda, and receiving an out of range for the 1600 x 900 @ 60
>> resolution it defaults to. <-- Is it even possible to support this
>> resolution? If not, no big deal to get another monitor...
>
> The monitor I typically use is 1920x1080-60, so I don't see why Panda
> wouldn't be capable of the lower res 1600x900-60.
>
> It may be that you need to tweak the timings that are used by the
> kernel.  Your monitor may not like the choices the kernel is making.
>

Currently the hdmi driver has a fixed table of understood resolutions
and timings that are supported, and 1600x900 is not in that table.
That said, I'm not entirely sure what the limitation is when it comes
to adding new timings, or just having a set of contraints about
horiz/vert resolutions and pixel clocks. (But I'm not the display
driver expert, I just happen to be a bit familiar with some of that
code.)

(But, the output from parse-edid only listed one possible timing,
1600x900@60.. which is a slightly strange thing. Usually monitors
advertise a couple resolutions.)

Adding a couple folks from the display team in case they aren't
already on this list.

BR,
-R

[K, Mythri P]

Hi,
There is a list of supported timings in the HDMI driver, If you have validated any other timing you are free to add it.
Yes 1600 * 900 is not in the table. List of timings that are supported can be found in
http://omappedia.org/wiki/Bootargs_for_enabling_display

section "How to read and set EDID timings for HDMI"

You can check with the custom_edid_timing sysfs referred in the link above to find all the timings supported by your TV in the first place to start.

Thanks and regards,
Mythri.