hdmi o/p on beagle board

Hi,
I am trying to connect beagle board to a Tv via HDMI cable. I can see the angstrom logo before loading the kernel but once the kernel is loaded the screen shows “no signal”.
I have tried various combinations of u-boot arguments provided by
http://elinux.org/BeagleBoardFAQ#Display_resolutions_.231
but nothing seems to work.
I am using the kernel and filesystem provided by the following link
http://www.angstrom-distribution.org/demo/beagleboard/

can somebody plz help me ?

thanks
Priyanka Sharma

Hi,

you can have a look at [1]. At the moment the only mode that the DSS2
can output on a HDTV (with the right pixclock of 74.25 MHz) set is the
720p@60 mode.
However, as far as I remember the DDS2 does a lookup in modedb.c,
where this mode is not present.
You can pick up the right mode in mansr's patch [2], put it in your
modedb, recompile and this should work.

Hope it helps,
Matthieu.

[1] http://groups.google.com/group/beagleboard/browse_thread/thread/89654a5ac60b82a9#
[1] http://git.mansr.com/?p=linux-omap;a=commitdiff;h=80fe5350fcb8feeae2db01b0173c39077b656ecf

hi,
thanks for the reply. But I think that the patch may not work for all the TV’s. Here I am using LG Xcanvas TV. Is there some way to find out which pixel clock rate the Tv supports ?
Also could you tell us from where we should check out the kernel source code?

thanks

hi,
thanks for the reply. But I think that the patch may not work for all the
TV's. Here I am using LG Xcanvas TV. Is there some way to find out which
pixel clock rate the Tv supports ?
Also could you tell us from where we should check out the kernel source
code?

thanks

Hi, You need to understand that Beagleboard has DVI-D over HDMI
interface. As per my understanding, you either need to HDMI to DVI-D
cable (avaiable in local market too) and DVI-D compatiable monitor. (
I have seen Dell and Benq monitor successfully displaying output
(sorry not having model nos. )
Alternatively, Your TV should support DVI-D signals over HDMI. Suggest
to confirm this in TV Manual.

rgrds,

Viral Sachde

Hi,

HDTV Timings are well standardized, see e.g.:
SMPTE 296M-2001
CEA Standard - A DTV Profile for Uncompressed High Speed Digital
Interfaces - CEA-861-E - March 2008

For kernel developpment, see:
http://elinux.org/BeagleBoard#Linux_kernel

You could also use OE, which is a rewarding experience in the long term:
http://elinux.org/BeagleBoardAndOpenEmbeddedGit

Regards,
Matthieu.

Hi, You need to understand that Beagleboard has DVI-D over HDMI
interface. As per my understanding, you either need to HDMI to DVI-D
cable (avaiable in local market too) and DVI-D compatiable monitor. (
I have seen Dell and Benq monitor successfully displaying output
(sorry not having model nos. )
Alternatively, Your TV should support DVI-D signals over HDMI. Suggest
to confirm this in TV Manual.

rgrds,

Viral Sachde

DVI-D and HDMI is one and the same thing seen from an electrical and video
format point of view.

However there is a difference in supported video modes - Many (if not all?)
monitors support reduced timing (giving shorter blanking intervals, and
thereby better bandwidth utilization), while not all TV's support this.
Unfortunately "full timing" is first supported by the OMAP from ES3.1 (maybe
ES3.0) which is mounted on Rev C (and B7 AFAIK) of the Beagle...

Best regards
  Søren

Viral Sachde <viral@allaboutif.com> writes:

hi,
thanks for the reply. But I think that the patch may not work for all the
TV's. Here I am using LG Xcanvas TV. Is there some way to find out which
pixel clock rate the Tv supports ?
Also could you tell us from where we should check out the kernel source
code?

thanks

Hi, You need to understand that Beagleboard has DVI-D over HDMI
interface. As per my understanding, you either need to HDMI to DVI-D
cable (avaiable in local market too) and DVI-D compatiable monitor.

Please, please stop spreading these misconceptions. HDMI and DVI-D
signals are EXACTLY THE SAME. The only difference is the connector.
The Beagle does not support HDMI audio, but this has *no* impact on
the video signal.

It is true that the driver currently in the linux-omap tree do not
support all possible timings, which does lead to problems with certain
TVs/monitors. This has nothing to do with HDMI vs. DVI; it is purely
a driver limitation that is removed with the new DSS2 drivers.

Mans, Thanks for clarrification.

Hi,
I tried with the patch provided in
http://git.mansr.com/?p=linux-omap;a=commitdiff;h=80fe5350fcb8feeae2db01b0173c39077b656ecf
and it worked for me. However the OTG port doesn’t seems to work . Does the latest 2.6.29 kernel provided by

git://[git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6.git](http://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6.git)

require some changes for OTG support?
thanks
Priyanka