Trying 1080p, dropping to 640x480

Hey there,

Just got my Pi.

I am using it with a 20" Hannspree HDMI screen that works fine with my iPad and with a PC I've got on a switch. Trying to go via HDMI to 1080p, which the display supports. Whenever I choose this mode (group 2 mode 82), or many other modes of particularly high res, the system just boots into 640x480.

Any ideas? Here's my config.txt:

- - - - -
#hdmi_safe=1

disable_overscan=1

#overscan_left=0
#overscan_right=0
#overscan_top=0
#overscan_bottom=0

hdmi_force_hotplug=1

hdmi_group=2
hdmi_mode=34

#hdmi_drive=1

config_hdmi_boost=4

#sdtv_mode=2

#arm_freq=800
- - - - -

The highest I've gotten is group 2 mode 47 -- 1400x900. Thanks.



bp

Have you tried http://elinux.org/RPi_config.txt#Which_values_are_valid_for_my_monitor.3F to see which specific settings are possible?

Try ignoring the EDID. Also you say group 2 (DMT) maybe CEA would be better?

Code: Select all

 hdmi_ignore_edid=0xa5000080
hdmi_group=1
hdmi_mode=16

^ What I would try in config.txt

Those last settings work, but I get occasional blanking and no setting I try for overscan correction will get me a "native" match for my 1920x1080 display.

I don't understand why it would jump to 640x480 when I set group 2 mode 82. Is it detecting the screen can't handle it? Is there a way to tweak the dot clock? I had to do this to get my SAM 440 (PPC Amiga thing) working at 1920x1080 (on the Amiga vidcard side). ?

Thanks. Frustrated...



bp

[dom]

@blakespot
The blanking may be fixed with config_hdmi_boost here:
http://elinux.org/R-Pi_Troubleshooting# ... VI_monitor

Yes, if you select a mode the monitor doesn't report it supprots in the EDID, it will be ignores and it falls back to 640x480 (a manditory mode).
You need the hdmi_ignore_edid to force a mode that is not reported as supported.

Hmmm, it drops to 640x480 even with the hdmi_ignore_edid=0xa5000080 added.

Shouldn't it just display nothing if my screen does not support it? Why would it jump to 640 in that force situation? Something else going on here, I wonder?



bp

Hi,

did you have check the setting of your screen ?

For example, on my TV, i have to use the mode "Fit screen" to have a full size screen show without overscan. If i use the mode "Original", "16:9", "4:3", "zoom", etc... my TV don't use all the screen or overscan.


PS: I'm French, so sorry for my bad English

@blakespot - so how is that going? Is there a way or isn't there one to make it work in native 1080p? The fact that its ignoring the HDMI auto detect _ignore option is laughable - who knows how many other settings that the "experts" claim to exist are total gibberish....

[dom]

Hmmm, it drops to 640x480 even with the hdmi_ignore_edid=0xa5000080 added.

Please post output of:
cat /boot/config.txt
/opt/vc/bin/tvservice -s
/opt/vc/bin/tvservice -m CEA
/opt/vc/bin/tvservice -m DMT

Here you go:


http://pastebin.com/C3nVCFyQ
http://pastebin.com/3EFXb8M5
http://pastebin.com/JGRC9ME2

Thanks for trying to help.




bp

[dom]

http://pastebin.com/C3nVCFyQ
http://pastebin.com/3EFXb8M5
http://pastebin.com/JGRC9ME2

It looks like you are at 1440x900:
state: HPD high|DVI mode|HDCP off|composite off (0x120016), 1440x900 @ 60Hz, progressive

Where are you seeing 640x480?

Sorry -- here it is in mode 82 = 1080p and the ignore is set...


http://pastebin.com/5Xzy4qAQ
http://pastebin.com/1WSWQh0f

Hmm...



bp

[dom]

Can you attach your edid.dat. You will have to zip it for forum to accept it.

My edid.dat is 0 bytes when /opt/vc/bin/tvservice -d edid.dat is executed in this gfx mode...


bp

Sorry, I didn't sudo generate the file. Disregard my last comment.

Here: http://pastebin.com/BaaMZU36

Thanks!



bp

[dom]

Sorry, I didn't sudo generate the file. Disregard my last comment.

Here: http://pastebin.com/BaaMZU36

Thanks!



bp

Could you attach the binary edit.dat file (zipped up).

Here it is.

[dom]

@blakespot
Thanks. I see the issue you are seeing. I've tweaked the behaviour of hdmi_ignore_edid, can you test it:
https://dl.dropbox.com/u/3669512/temp/start.elf

Note: this is 128M memory split. If testing is okay (and hdmi guy agrees the change is okay), I'll push out an updated firmware in next day or two.

Yes - that works! Thanks so much!

I still have occasional blanking issues with this mode and some others. I have boost set to 7 -- it showed a blank display at 4. This is a pretty cheapo HANNspree 20" wide display.



bp

[dom]

I still have occasional blanking issues with this mode and some others. I have boost set to 7 -- it showed a blank display at 4. This is a pretty cheapo HANNspree 20" wide display.

Can you try a different HDMI lead?
While we've listed 7 as the maximum, I believe you can go up to 11.
This would not be generally recommended, as that is way above the spec, and a "sensitive" monitor might react badly.
However your combination of cable and monitor seems rather "insensitive", so you might get away with it.