TLC59108 backlight with ulcd7 moves the display resolution

Hi,

I have built 3.4.7 zImage with CONFIG_BACKLIGHT_TLC59108 set to y. Also the stable kernel applies patches for the beagle board to enable the backlight control.
After booting, the display resolution gets shifted. Has any one faced such issue?

I am using beagle board xm revc with ulcd7 and developed zimage and modules using stable-kernel https://github.com/RobertCNelson/stable-kernel/tree/v3.4.x.

Any help on this will be appreciated.

Regards,
Ketan

Noticed that too.. The default u-boot in the images I push out has a
patch(1) to automatically recenter the image, makes you wonder if the
backlight driver is shifting it again after that.. Can you rebuild
u-boot mainline and copy the u-boot.img over the one on your sd card
to see if that's causing it..

1: https://github.com/RobertCNelson/Bootloader-Builder/blob/master/patches/v2012.04/0001-beagle-ulcd-passthru-support.patch#L66

Regards,

Hi Robert,

Tried building the u-boot-2012.07 with only change in include/configs/omap3_beagle.h (for enabling the CONFIG_CMD_BOOTZ and CONFIG_SUPPORT_RAW_INITRD). Still its getting shifted.

Regards,
Ketan

Hi Robert,

The following line in linux drivers/video/backlight/tlc59108.c causes this issue:
line 121: i2c_smbus_write_byte_data(data->client, TLC59108_LEDOUT1, 0x15);

After commenting this, the issues is fixed.

Thanks and Regards,
Ketan