On Thu, 2018-03-15 at 10:11 +0100, Lucas Stach wrote:
Right now the vblank event completion is racing with the atomic update, which is especially bad when the PRE is in use, as one of the hardware issue workaround might extend the atomic commit for quite some time.
If the vblank IRQ happens to trigger during that time, we will prematurely signal the atomic commit completion to userspace, which causes tearing when userspace re-uses a framebuffer we haven't managed to flip away from yet.
Signed-off-by: Lucas Stach l.stach@pengutronix.de
This trades the tiny (on i.MX6Q) or not so tiny (on i.MX6QP) risk of returning a vblank event completion too early for the tiny risk to miss a vsync interrupt, and to return a vblank event completion a frame too late. Applied to imx-drm/fixes.
regards Philipp