[PATCH 6/6] prime: add rotation support for offloaded outputs

[Chris Wilson]

On Mon, Jun 15, 2015 at 09:25:01AM +1000, Dave Airlie wrote:
> One of the lacking features with output offloading was
> that screen rotation didn't work at all.
> 
> This patch makes 0/90/180/270 rotation work with USB output
> and GPU outputs.
> 
> When it allocates the shared pixmap it allocates it rotated,
> and any updates to the shared pixmap are done using a composite
> path that does the rotation. The slave GPU then doesn't need
> to know about the rotation and just displays the pixmap.

This doesn't seem right. The slaved output already has the transform
details and currently the ability to apply HW transformation when
possible. It also needs to know the transform for applying the HW
cursor. I guess the problem you face is that you want the host GPU to
accelerate the rotation for a slaved USB device?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre