At Tue, 17 Jun 2014 09:54:07 +1000,
Benjamin Herrenschmidt wrote:

On Mon, 2014-06-16 at 17:35 +1000, Benjamin Herrenschmidt wrote:

quoted

I somewhat doubt that this (and 5:5:5) actually work, do they ? the
green gets split into two separate fields, which we can't express
properly here...

So the conclusion of further investigation is:

 - The right fix is to fix qemu to flip endian

 - There's an open discussion as to whether qemu could do it
automatically when the guest endian changes on powerpc as a quick fix,
the long run approach is to have a register to control it, I'm working
on it. offb can then "learn" to flick it like it does the palette hack
today.

 - If we want to ever support foreign endian offb with X, we need to do
things a bit differently based on the foreign endian bit that is already
there.

 - We must revert the existing cmap swap patch from the kernel, it's
broken and will break things when we fix qemu (and breaks with real HW
in LE mode). I've sent a revert request to Linus and CC'ed stable.

Yeah, I agree.  Both the current palette fix and my patch are really
wrong band-aiding.

(Though, the issue in X is rather a problem of X itself.  X should
 work with the tweaked RGB offsets.)


thanks,

Takashi