Snowball/Panda: Display does not come up when using HDMI to DVI converter cable

[Abhishek Paliwal]

Description:
==========
Connect HDMI out on Board to DVI input on display(Monitor) Using HDMI-DVI convertor cable.
Board boots up but display does not come up. Issue is not seen with HDMI-HDMI cable connected.

On Pandaboard:
Tried both HDMI and DVI port(next to ethernet port)
With DVI port lot of error messages printed continously:
----------Logs ----------
[ 16.450286] WARNING omaplfb (OMAPLFBPresentSyncAddr 297): Unable to sync with display 2!
[ 16.968536] WARNING omaplfb (OMAPLFBPresentSyncAddr 297): Unable to sync with display 2!
[ 17.489410] WARNING omaplfb (OMAPLFBPresentSyncAddr 297): Unable to sync with display 2!
----------Logs ----------

With HDMI port no error messages seen on Serial port but display does not show anything during/after bootup.

On Snowball:
No error messages seen on Serial port, display remains dark, HDMI data not detected.

Reproducible:
===========
Yes, 5/5

IMPACT:
========
Unable to use HDMI-to-DVI out feature.

Steps:
==========
Precondition: Connect HDMI-to-DVI convertor cable from DUT to Monitor
1. Bootup DUT
2. Observe the display during/after bootup.
Issue: Display never gets any data and does not show anything during/after bootup.

Same cable is checked with another reference phone and it works fine - so its not a cable/monitor issue.

Hardware:
==========
Snowball: V5
HDMI Out to TV - via HDMI-DVI , HDMI Out on DUT and DVI in to Monitor
(Like : http://www.ebay.in/itm/HDMI-DVI-D-DUAL-LINK-GOLD-PLATED-CABLE-1-5-METER-/190575326234?pt=LH_DefaultDomain_203&hash=item2c5f2cb41a)
Serial port connected.

Software:
==========
https://android-build.linaro.org/builds/~linaro-android/staging-panda-11.10-release/
build 1

https://android-build.linaro.org/builds/~linaro-android/staging-snowball-11.10-release/
build 1

Logs:
======
Bootup logs and dmesg attached.

[Frans Gifford (fgiff)]

On Snowball, /sys/devices/av8100_hdmi.1/hdmisdtvswitch controls the video output, 0=HDMI, 1=SDTV or 2=DVI. I'm used to using 'echo 2 > /sys/devices/av8100_hdmi.1/hdmisdtvswitch' to make output work with a HDMI to DVI converter. HDMI and CVBS outputs are mutually exclusive in the driver (and there's an existing bug #837881 about CVBS not working properly).

For Snowball, do we need to get someone within STE to explain why we need to specify if the board is connecting using HDMI or DVI?

[Abhishek Paliwal (abhishek-paliwal)]

Snowball:
-----------
Using Build : https://android-build.linaro.org/builds/~linaro-android/staging-snowball-11.10-release/#build=6
I'm able to get DVI Out working by just connecting HDMI-to-DVI cable from device to DVI input on Monitor.
(No need for "echo 2 > /sys/devices/av8100_hdmi.1/hdmisdtvswitch" )

[Abhishek Paliwal (abhishek-paliwal)]

Fixed in :
https://android-build.linaro.org/builds/~linaro-android/staging-snowball/#build=90