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piglet
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Setting up DVI-D output [solved]

Sat May 26, 2012 4:25 pm

I bought a 1M HDMI Male to DVI-D 24+1 dual link cable from ebay.

It arrived this morning, and I was concerned to see it was "Pluscom" branded. The two "Pluscom 7 port USB 2 hub"s I'd bought had turned out to be utter rubbish.

When plugged into either of my two DVI-D monitors they see no signal from the Pi at boot. I tried setting the /boot/config.txt to hdmi_group=2 and hdmi_mode=4 for a lower resolution (confirmed working on HDMI lead). Still no signal seen by either monitor.

The only other HDMI device I have is a digial camera. No signal seen from that either when using this cable.

Am I doing something wrong or is this Pluscom cable as big a pile of poo as the USB hubs?

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piglet
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Re: Setting up DVI-D output

Sat May 26, 2012 9:16 pm

Ok - after a lot of hassle & partition resizing to allow firmware update I got edid output:

Now...to work out what this means for setting up correct config.txt settings...
Parsing edid.dat...
HDMI:EDID version 1.3, 0 extensions, screen size 47x30 cm
HDMI:EDID features - videodef 0x80 standby suspend active off; colour encoding:RGB444|YCbCr422; sRGB is not default colourspace; preferred format is native; does not support GTF
HDMI:EDID found monitor range descriptor tag 0xfd
HDMI:EDID monitor range offsets: V min=0, V max=0, H min=0, H max=0
HDMI:EDID monitor range: vertical is 56-75 Hz, horizontal is 30-81 kHz, max pixel clock is 170 MHz
HDMI:EDID monitor range does not support GTF
HDMI:EDID found monitor name descriptor tag 0xfc
HDMI:EDID monitor name is ZM-M220W_D_
HDMI:EDID ignored unknown descriptor tag 0x0
HDMI:EDID found preferred DMT detail timing format: 1680x1050p @ 60 Hz (58)
HDMI:EDID established timing I/II bytes are BF EF 80
HDMI:EDID found DMT format: code 4, 640x480p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 5, 640x480p @ 72 Hz in established timing I/II
HDMI:EDID found DMT format: code 6, 640x480p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 8, 800x600p @ 56 Hz in established timing I/II
HDMI:EDID found DMT format: code 9, 800x600p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 10, 800x600p @ 72 Hz in established timing I/II
HDMI:EDID found DMT format: code 11, 800x600p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 16, 1024x768p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 17, 1024x768p @ 70 Hz in established timing I/II
HDMI:EDID found DMT format: code 18, 1024x768p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 36, 1280x1024p @ 75 Hz in established timing I/II
HDMI:EDID standard timings block x 8: 0xB300 8180 8140 714F 0101 0101 0101 0101
HDMI:EDID found DMT format: code 58, 1680x1050p @ 60 Hz (16:10) in standard timing 0
HDMI:EDID found DMT format: code 35, 1280x1024p @ 60 Hz (5:4) in standard timing 1
HDMI:EDID found DMT format: code 32, 1280x960p @ 60 Hz (4:3) in standard timing 2
HDMI:EDID found DMT format: code 21, 1152x864p @ 75 Hz (4:3) in standard timing 3
HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
HDMI:EDID best score mode is now DMT (5) 640x480 @ 72 MHz with pixel clock 31 Hz (score 44236)
HDMI:EDID best score mode is now DMT (6) 640x480 @ 75 MHz with pixel clock 31 Hz (score 46080)
HDMI:EDID best score mode is now DMT (8) 800x600 @ 56 MHz with pixel clock 36 Hz (score 53760)
HDMI:EDID best score mode is now DMT (9) 800x600 @ 60 MHz with pixel clock 40 Hz (score 57600)
HDMI:EDID best score mode is now DMT (10) 800x600 @ 72 MHz with pixel clock 50 Hz (score 69120)
HDMI:EDID best score mode is now DMT (11) 800x600 @ 75 MHz with pixel clock 49 Hz (score 72000)
HDMI:EDID best score mode is now DMT (16) 1024x768 @ 60 MHz with pixel clock 65 Hz (score 94370)
HDMI:EDID best score mode is now DMT (17) 1024x768 @ 70 MHz with pixel clock 75 Hz (score 110100)
HDMI:EDID best score mode is now DMT (18) 1024x768 @ 75 MHz with pixel clock 78 Hz (score 117964)
HDMI:EDID best score mode is now DMT (21) 1152x864 @ 75 MHz with pixel clock 108 Hz (score 249298)
HDMI:EDID DMT mode (32) 1280x960p @ 60 Hz with pixel clock 108 MHz has a score of 247456
HDMI:EDID best score mode is now DMT (35) 1280x1024 @ 60 MHz with pixel clock 108 Hz (score 257286)
HDMI:EDID DMT mode (36) 1280x1024p @ 75 Hz with pixel clock 135 MHz has a score of 196608
HDMI:EDID best score mode is now DMT (58) 1680x1050 @ 60 MHz with pixel clock 146 Hz (score 5311680)
HDMI:EDID preferred mode remained as DMT (58) 1680x1050p @ 60 Hz with pixel clock 146 MHz
HDMI:EDID has only DVI support and no audio support
edid_parser exited with code 0

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piglet
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Re: Setting up DVI-D output

Sat May 26, 2012 9:31 pm

Humph! No matter what I do I get absolutely nothing on the monitor.

pi@raspberrypi:/opt/vc/bin$ ./tvservice -m CEA
Group CEA has 0 modes:
pi@raspberrypi:/opt/vc/bin$ ./tvservice -m DMT
Group DMT has 0 modes:
pi@raspberrypi:/opt/vc/bin$ ./tvservice -s
state 0x40001, 720x480 @ 60Hz, interlaced

dom
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Re: Setting up DVI-D output

Sat May 26, 2012 10:24 pm

If Pi is not detecting any modes, then I'd suspect the cable is bad.
You could try
hdmi_force_hotplug=1
and see if you get anything, in case it is just the hotplug signal missing.

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rpdom
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Re: Setting up DVI-D output

Sun May 27, 2012 6:14 am

I also bought a 1m HDMI-DVI-D cable via ebay. I believe it was a Pluscom one.

It has been working fine on with my Pi and Dell monitor - until I did a firmware upgrade using rpi-update. Now I only get composite output.

I did keep a backup of my SD cards though, so was able to go back and check that the cable still worked with the old firmware.

I have both Raspbian and Debian systems for my Pi.

Oh, is there any chance that Hexxeh (or someone) could make rpi-update stop/start vcfiled if required?

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piglet
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Re: Setting up DVI-D output

Sun May 27, 2012 8:08 am

That's interesting - as I couldn't parse the edid output from "tvservice -d" using the deb squeeze image I'd been using I used the updater and then parsed it.

The output from "tvservice -m" was from after the updater had run. I think maybe that output was because it was only outputting composite.

I'll spend more time later using the forcing hotplug option to see if that helps.

I have to say that monitor support being automatic is something that seriously needs addressing before some poor tech in the schools has to try and work out individual settings for each dvi monitor brand they have (lots in most cases)

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piglet
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Re: Setting up DVI-D output

Sun May 27, 2012 10:23 am

Yes. Got it. hdmi_force_hotplug=1 was needed.


For anyone else with similar problems, and getting composite output only:


sudo vi /boot/config.txt
(press i for insert mode, then type in the next line)
hdmi_force_hotplug=1
(press ecs then : then wq then enter to save the file)
sudo reboot

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rpdom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 11:51 am

I just tried hdmi_force_hotplug=1, and it doesn't seem to have helped. I still only get composite output.

Output from tvservice -m is as listed above by piglet.
Output from tvservice -s is slightly different:
state 0x40002, 720x480 @ 60Hz, interlaced

Is there anything else I can try, other than reverting to the old firmware?

dom
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Re: Setting up DVI-D output

Sun May 27, 2012 12:48 pm

rpdom wrote:It has been working fine on with my Pi and Dell monitor - until I did a firmware upgrade using rpi-update. Now I only get composite output.
First please check you don't have a config.txt file that is causing the problem. Rename it if you have, and confirm problem still exists. Asssuming it does:

All past firmware's are stored in github. The start.elf file is the significant one. If you can idendify the exact firmware that broke things for you, we can probably fix the problem.

Go to:
https://github.com/raspberrypi/firmware ... /start.elf

Choose a date, click "browse code", and then "view raw" and you can download a specific start.elf. Put this on boot partition of sdcard and see if display works.
(technically you should update all the firmware files, but just changing start.elf will probably boot far enough to see if display is working).

Repeat until you find the newest start.elf that still worked, and let me know. I can then look at the changes for that version and hopefully produce a new firmware that still works for you.

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rpdom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 1:53 pm

Thanks Dom,

All start.elf files up to and including both 30th April images work ok. The one from 16th May fails as before.

I did move my config.txt to config.old before testing this, as requested, but it only has the one entry "disable_overscan=1".
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 3:51 pm

Thanks rpdom.

There are two checkins to our source tree that affect HDMI between those two binary builds. I've made a build avoiding the second of those. Can you try:
https://dl.dropbox.com/u/3669512/backou ... /start.elf

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rpdom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 4:07 pm

Thanks Dom,

I tried that file and it works ok. Then I put my config.txt back and rebooted and that works too.

Cheers,

Dom (rpdom)
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 4:32 pm

Just to be sure, this is the next checkin:
https://dl.dropbox.com/u/3669512/313976/start.elf

I'd hope that fails for you.

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rpdom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 5:06 pm

Dom,

I'm sorry to say that that file works too. It must be something else that's changed.

just to be sure, I re-downloaded the 16th May file and tried it again. It failed still.
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 6:22 pm

That's a shame. How about this one:
https://dl.dropbox.com/u/3669512/315107/start.elf

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rpdom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 6:51 pm

Strange... that one works too.
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Sun May 27, 2012 10:19 pm

Well this should be the same as 16th May github one:
https://dl.dropbox.com/u/3669512/315110/start.elf

so should fail (although from the changes between this and last one, I'm not sure how it could fail...)

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rpdom
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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 5:02 am

Yes, that one fails.
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 1:16 pm

This should be last one (there is no 315109 in our branch):
https://dl.dropbox.com/u/3669512/315108/start.elf

Should just be a sanity check, as I feel it must fail (but I've said that before).

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rpdom
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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 3:59 pm

Yep, that file failed too. That's good news, yes?
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 6:37 pm

rpdom wrote:Yep, that file failed too. That's good news, yes?
Kind of. You have identified that CL#315107 produces a signal on HDMI.
CL#315108 does not produce a signal on HDMI and falls back to composite (can you confirm it is correctly driving composite?)

Now that CL#315108 initialises the UART. It supports loading a device tree file (only if you request it in config.txt).

It also replaces the fread of the kernel which for some reason was being done in 4K chunks in a loop to a single fread.
I think this is the most likely cause - it possibly loads a little quicker and exposes a race condition.

Now, when moving code around at weekend I did find and fix a race condition that could affect HDMI detection.

I'm going to cross my fingers and hope top of tree fixes the problem for you:
https://dl.dropbox.com/u/3669512/start.elf

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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 7:22 pm

"CL#315108 does not produce a signal on HDMI and falls back to composite (can you confirm it is correctly driving composite?)"

Yes, composite output worked in all cases (from what I can recall). I have a composite to VGA adapter plugged into the monitor's VGA input, so could easily check by switching inputs.

And, your latest file works perfectly. Thank you for all your hard work on this awesome project and your patience. :D
Unreadable squiggle

dom
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Re: Setting up DVI-D output [solved]

Mon May 28, 2012 8:14 pm

I'm very relieved to hear that. Thanks for your help in testing.

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