[PATCH xserver 1/2] modesetting: Fix reverse prime partial update issues on secondary GPU outputs

[Dave Airlie]

On 15 September 2016 at 23:47, Hans de Goede <hdegoede at redhat.com> wrote:
> When using reverse prime we do 2 copies, 1 from the primary GPU's
> framebuffer to a shared pixmap and 1 from the shared pixmap to the
> secondary GPU's framebuffer.
>
> This means that on the primary GPU side the copy MUST be finished,
> before we start the second copy (before the secondary GPU's driver
> starts processing the damage on the shared pixmap).
>
> This fixes secondary outputs sometimes showning (some) old fb contents,
> because of the 2 copies racing with each other, for an example of
> what this looks like see:

Reviewed-by: Dave Airlie <airlied at redhat.com>