No longer able to drive VGA monitor

[keylevel]

Up to and including the start.elf file from the 18th April (4712300) I was able to use an HDMI to VGA converter to drive my monitor and I could select the resolution by using a config.txt file with the following contents:

hdmi_drive=2
hdmi_group=2
hdmi_mode=0x10
disable_overscan=1

This doesn't work with any of the later versions - the monitor just stays in standby. It still works with the default configuration (i.e. when there's no config.txt).

Is there something I need to add to config.txt for the later versions?

[popcornmix]

Can you try latest firmware (use Hexxeh's udpater tool)?
Can you then try without a config.txt file?
Can you report output of /opt/vc/bin/tvservice -s

[apramorbis]

I think I've been running into the same issue. Created a forum thread yesterday here with relevant logs and edid dump.

I can confirm that after removing every hdmi related setting from the config.txt I'm now getting all the DMT modes added and my monitor's native resolution is autoselected on boot and works fine.
Trying to define the mode explicitly in config.txt without ignore_edid results in no video.

[popcornmix]

Can you give an example config.txt file that doesn't work? What does:
/opt/vc/bin/tvservice -s
report after booting with that config.txt?

[apramorbis]

Sure

Not working (no video, monitor in standby):

[root@alarmpi ~]# /opt/vc/bin/tvservice -s
state 0x140002, 720x480 @ 60Hz, interlaced
[root@alarmpi ~]# /opt/vc/bin/tvservice -m DMT
Group DMT has 1 modes:
           mode 4: 640x480 @ 60Hz, progressive
[root@alarmpi ~]# /opt/vc/bin/tvservice -m CEA
Group CEA has 4 modes:
           mode 1: 640x480 @ 60Hz, progressive
           mode 2: 720x480 @ 60Hz, progressive
           mode 3: 720x480 @ 60Hz, progressive
  (native) mode 4: 1280x720 @ 60Hz, progressive
[root@alarmpi ~]# cat /boot/config.txt
hdmi_drive=2
hdmi_group=2
hdmi_mode=16
#arm_freq=800
#disable_overscan=1

[root@alarmpi ~]#

Working at monitor's native resolution:

[root@alarmpi ~]# /opt/vc/bin/tvservice -s
state 0x120016, 1024x768 @ 60Hz, progressive
[root@alarmpi ~]# /opt/vc/bin/tvservice -m DMT
Group DMT has 9 modes:
           mode 4: 640x480 @ 60Hz, progressive
           mode 5: 640x480 @ 72Hz, progressive
           mode 6: 640x480 @ 75Hz, progressive
           mode 9: 800x600 @ 60Hz, progressive
           mode 10: 800x600 @ 72Hz, progressive
           mode 11: 800x600 @ 75Hz, progressive
           mode 16: 1024x768 @ 60Hz, progressive
           mode 17: 1024x768 @ 70Hz, progressive
           mode 18: 1024x768 @ 75Hz, progressive
[root@alarmpi ~]# /opt/vc/bin/tvservice -m CEA
Group CEA has 7 modes:
           mode 1: 640x480 @ 60Hz, progressive
           mode 2: 720x480 @ 60Hz, progressive
           mode 3: 720x480 @ 60Hz, progressive
  (native) mode 4: 1280x720 @ 60Hz, progressive
           mode 17: 720x576 @ 50Hz, progressive
           mode 18: 720x576 @ 50Hz, progressive
           mode 19: 1280x720 @ 50Hz, progressive
[root@alarmpi ~]# cat /boot/config.txt
#arm_freq=800
#disable_overscan=1

[root@alarmpi ~]#

[popcornmix]

You don't have very latest firmware (it should decode the state as text with tvservice -s). Can you try updating and see if anything changes.

[apramorbis]

I've just ran the updater tool again after the mirroring of the latest changes to the other repo finished but I'm still getting a hex state code from tvservice -s. Double checked and my tvservice binary is the same as the one in this repo.

[popcornmix]

Good news is I've found a bug. The hdmi_group was used in two places in the code, once as a force this group, and once as a reject this group.

Basically hdmi_group/hdmi_mode would only be accepted if the mode number was valid for the other group.
That should be fixed now. Rebuilding...

Done. Pushed to github. Should be enough to just update start.elf.

[apramorbis]

Thanks! Configured DMT modes work now and all the correct DMT modes show up for tvservice -m DMT but CEA modes appear to have disappeared. Not sure if that's preferred when a DMT mode is set in config or if it's an issue.

[root@alarmpi ~]# /opt/vc/bin/tvservice -s
state 0x12001a, 1024x768 @ 70Hz, progressive
[root@alarmpi ~]# /opt/vc/bin/tvservice -m DMT
Group DMT has 9 modes:
           mode 4: 640x480 @ 60Hz, progressive
           mode 5: 640x480 @ 72Hz, progressive
           mode 6: 640x480 @ 75Hz, progressive
           mode 9: 800x600 @ 60Hz, progressive
           mode 10: 800x600 @ 72Hz, progressive
           mode 11: 800x600 @ 75Hz, progressive
           mode 16: 1024x768 @ 60Hz, progressive
           mode 17: 1024x768 @ 70Hz, progressive
           mode 18: 1024x768 @ 75Hz, progressive
[root@alarmpi ~]# /opt/vc/bin/tvservice -m CEA
Group CEA has 0 modes:
[root@alarmpi ~]# cat /boot/config.txt
hdmi_drive=2
hdmi_group=2
hdmi_mode=17
#arm_freq=800
#disable_overscan=1

[root@alarmpi ~]#

[popcornmix]

hdmi_group actually filters out all non matching entries.
So you can just specify "hmdi_group=1" if you want the best CEA mode.
So what you are seeing is expected (CEA modes will return if your remove config.txt entries).

[apramorbis]

Ah ok, all good then. Thanks! :D

[keylevel]

Confirmed - that's fixed what I was seeing as well.

Thanks, and sorry I didn't get on the case when asked - I've got a day job that gets in the way ;-)

Chris