Comment 5 for bug 899598

The if condition is different, because the code changed upstream to calculate bpp better for all pipes on >= ironlake.

But my backport was wrong, as pixel_clock * 3 == (pixel_clock * 24) / 8, so it wouldn't work for external monitors I expect, only for embedded display port configurations. Which means wouldn't work on your case, in the backport should have accounted for the else condition as well.

I'm attaching an updated patch, and will send to the list for inclusion in the ubuntu oneiric kernel.