Issue: LCD panels remain dark or turn white on Overo COMs running Linux kernel version prior to 2.6.32 and older version of u-boot.
Update on March 30th 2010:
Resolution:
- The LCD panel should function according to specification if the Overo COM is running Linux 2.6.32 and higher as well as a recent version of U-Boot.
- Customers can update the software on their Overo COM to a recent version of U-Boot and Linux 2.6.32 or higher via the instructions posted here: Downloading pre-built images .
Each customer is reminded to update the software image on their Overo COM to a current release as other issues may have been resolved beyond this LCD panel issue. A quick check to make sure the Overo COM has a recent image would be to note the Linux version that gets printed on the console at boot time.
root@overo:~# uname -a
root@overo:~# ls -l /boot
As usual, please note that the 'defaultdisplay' variable should be correctly set in your U-Boot environment as per instructions here .
A Customer Experience
Here are some testing notes from an engineer who recently performed this update:
I tested this particular feed: http://www.sakoman.com/feeds/omap3/glibc/images/overo/201002031857/
I loaded a new MLO, u-boot, uImage and console rootfs onto my Chestnut43 board with an Overo Air COM using roughly the instructions from this page: http://www.gumstix.net/Setup-and-Programming/view/Overo-Setup-and-Programming/Creating-a-bootable-microSD-card/111.html
Note that is important that MLO is copied onto the card FIRST and that this is a fresh FAT partition! To ensure no problems with U-Boot environment variables, I erased my U-Boot environment variables by interrupting the boot sequence and issuing this command: 'nand erase 0x00240000 0x00040000'
Finally, I set the 'defaultdisplay' variable in U-Boot and booted the board and the display came up with no problems".
