Comment 29 for bug 1173491

Thanks for the advice, Chris! The --newmode/--addmode arguments will be very useful. I do want to use that mode quite badly, as the display represents all other resolutions I tried (of which there were many on the older kernels) very badly.

I presently cannot remember on what basis I concluded that 14x9 was the display's actual native resolution, so I can't claim I'm certain that that is correct. However, I am quite certain that the actual native resolution is not on the list of detected resolutions. I will try to back my claims up with something solid (however, it will have to wait till tomorrow, at least, as I am not presently near the system in question).

I did try analysing the EDID data, using the "read-edid" tools from http://www.polypux.org/projects/read-edid/ . The tools did complain that there was something unexpected about the EDID data and that it was probably bad. Thus I suspect that the EDID data is indeed bad and that something changed about how faulty data is handled between kernel 3.7 and 3.8, causing the previously detected modes (of which there were many more) to no longer be detected.

As for the additional logs of the working 14x9 mode: If you are still interested in them, then I will be happy to try and produce/collect them, when I get back to the affected system. I am not quite clear on what you are after, though. If you are just interested in a set of logs where the system successfully booted with light-dm switching to the 14x9 mode, then the original set of logs I uploaded seems to be what you are looking for. In particular, you can see:

[+1.57s] DEBUG: Connecting to XServer :0
[+1.57s] DEBUG: Launching process 1674: xrandr --output HDMI2 --primary --mode 1440x900
[+2.59s] DEBUG: Process 1674 exited with return value 0
[+2.59s] DEBUG: Exit status of xrandr --output HDMI2 --primary --mode 1440x900: 0
[+2.59s] DEBUG: Starting greeter

That just shows that it didn't mind using the mode in question on kernel 3.7 (at least on RC8). However, I suspect that you were after something more specific. If so, please let me know.

Thanks for all your help, Chris!