On 03/07/12 22:03, the mail apparently from David Cullen included:
Hello, Andy,
On 7/3/2012 2:14 AM, Andy Green wrote:
On 07/03/12 03:47, the mail apparently from David Cullen included:
After running some experiments here, I discovered that the Linaro Ubuntu images only work with displays that have a native resolution of 1920x1080.
I tried to use kernel command line arguments to force the resolution to work with my 1680x1050 monitor, but my changes had no effect. I wanted to look at the kernel source for the Linaro Ubuntu image because I can probably figure out the correct kernel command line arguments from that. However, I could not figure out which git tree to use.
Just to be clear, the kernel is recognizing your monitor and coming up with kms OK at your native resolution?
What's "kms"? But yes, the kernel appears to be driving the monitor at the native resolution.
Kernel Mode Select.
IIUI Xorg starts and you get a pointer you can move around but Xorg chokes somewhere.
If Xorg choked, would I even have a mouse pointer?
Right what I mean is Xorg + display manager and points south, ie, your "desktop" choked somewhere.
Did you have a look at the Xorg logs then, or try to come up in runlevel three and do startx at the terminal?
No. I'm not an expert at troubleshooting Xorg problems, so I didn't even think about doing any of that. I'll give it a shot and post my findings.
You can often hear about problems in the display manager logs, for gdm it's /var/log/gdm/:0-greeter.log I am not sure what it is on Ubuntu.
If you do start X from the commandline, you will get valuable stderr coming quite deep into the whole desktop startup process.
If I did get the idea I am not sure recooking the kernel will change much, it's actually doing its side (as distinct from SGX module perhaps) okay from the sound of it.
After looking at the kernel source for another project, I was able to figure out how to pass LCD panel timings via the kernel command line to get the resolution I needed. So one reason I wanted to look at the Linaro kernel source was to try to figure out how to force the DVI output to use a specific resolution and bit depth.
However, the image from here
http://cdimage.ubuntu.com/releases/12.04/release/ubuntu-12.04-preinstalled-d...
Well that is 12.04, the kernel will be quite different.
does display the GUI properly on my monitor, so I know it can be done. This raises the question, "What are the differences between the Ubuntu image and the Linaro image?" If the primary difference is the kernel, then rebuilding the kernel may fix the problem.
Well, good luck... I think a more certain result will come from finding some evidence from the desktop logs about where it gets stuck.
However, the real reason I need to rebuild the kernel has nothing to do with getting the GUI working. Unfortunately, it is not obvious to me how to acquire the source to the kernel that goes with the image here
http://releases.linaro.org/12.06/ubuntu/leb-panda/Using apt, I can easily get the source for the Ubuntu image mentioned above. So, I will be sticking with the Ubuntu image for now.
Ubuntu's Panda kernel as the Linaro Ubuntu LEB kernel, is based on our LT kernel here
http://git.linaro.org/gitweb?p=landing-teams/working/ti/kernel.git%3Ba=short...
I don't know where they put the exact tree, but they basically set their own config similar to our omap4plus_defconfig and add a bunch of UBUNTU SAUCE patches on top, almost all of which are affecting generic kernel code.
-Andy