This is only a bug in the Sputnik kamal13 and kamal14 kernels; Not a bug in standard Ubuntu kernels (standard Quantal doesn't support XPS13 backlight at all, and it works properly in standard Raring).
This is only a bug in the Sputnik kamal13 and kamal14 kernels; Not a bug in standard Ubuntu kernels (standard Quantal doesn't support XPS13 backlight at all, and it works properly in standard Raring).