Working with a customer trying to determine what is going on with their LCD Panel with Linux:
Board is a EMB-BT1, AAEON Mini ITX Baytrail, with E3845 Processor.
Panel is a AUO G156XW01 1366x768 24bit Panel
We have built the cable correctly because we can boot into Windows 8.1 and the LCD Panel looks good see picture:
We have tried Ubuntu 14.04 64bit, Lubuntu 14 64bit, Fedora 20 64bit, all three of these display this "fuzzy/noisy" image.
We downloaded the Timesys 18 Fedora Remix image and booted it up on the board and the LCD Panel looks perfect.
So there is something going on with the Intel Graphics driver when using the standard ISO files for Ubuntu and Fedora.
Please help me figure this out. I have attached different pictures in this discussion.
Those are our POR and the EMGD Linux driver for Baytrail is ported, provided, and supported by Timesys for us. For the other distributions, did you try to install EMGD manually? It may or may not install depending on the Kernel Version and X version in your particular distribution. If you have not installed then it is likely the i915 OTC driver is being used and that is not very Baytrail aware.
For EMGD, if the X versions do not match one that we provide in the release, it is unlikely to work unless you get lucky and the version we provide is backward or forward compatible with the X your distro uses.
If the kernel does not match, you will likely need to make the GART changes manually to your kernel source as we have in the install patches we provide for the POR kernels. That will take a bit of work but it is possible to port EMGD to a kernel it was not originally provided for in a release. The bigger issue IS the X version due to the version specific libraries we link into the X interface modules we provide.
If you DID successfully port EMGD, then I would take a look at the DTD you are using for your panel IF it does provide its own EDID. Did you also tune up the T1 through T5 timing values? AUO and Chi Mei panels are VERY particular about their power sequencing timing and if you are off, you can get distortion like that also.
Hope this helps.
I found the answer to my problem. I had to update the kernel to 3.15 Linux.
Now a new problem came up. When I only have the LVDS Panel connected I get no output from the LVDS connector. The LVDS comes up with HDMI or VGA plugged in.
Thank you for posting your question in Intel Embedded Community. Sorry for reply so late.
The issue description seems a bit unclear and I would like to have a better understanding before we start working on it. I would really appreciate if you could answer the following questions:
1. Is this the first LVDS panel you have used?
2. Does the LVDS work on another system?
3. Does the LVDS work if you go back to the original kernel you are using?
4. Does the vbios work, i.e. when you boot with i915.modeset=0?
If so please try to install the latest intel-gpultools and grab the out of intel_reg_dumper for both the working case and the broken case.
Please provide us more information about the exact issue to help you fix it as soon as possible.
Your reply is very important for us to ensure a proper resolution. Please get back to us with the above information in order to assist you accordingly.
I have figured out the answer, please see this bug report: https://bugs.freedesktop.org/show_bug.cgi?id=78795 https://bugs.freedesktop.org/show_bug.cgi?id=78795
I worked with Jesse Barnes and compiled a new kernel for our motherboard, and it worked. You can close this topic