tree 1d7b58e0db4c25934af329c9c74aa555c320455f
parent e59e2c664f3380642138bb27914237380ff778ce
author Nicolai Hähnle <nicolai.haehnle@amd.com> 1487789946 +0100
committer Emil Velikov <emil.l.velikov@gmail.com> 1489604071 +0000

st/mesa: inform the driver of framebuffer changes before compute dispatches

Even though compute shaders cannot access the framebuffer, there is a
synchronization issue when a compute dispatch accesses a texture that
was previously bound and drawn to as a framebuffer.

Section 9.3 (Feedback Loops Between Textures and the Framebuffer) of
the OpenGL 4.5 spec rather implicitly clarifies that undefined behavior
results if the texture is still attached to the currently bound
framebuffer. However, the feedback loop is broken when the application
changes the framebuffer binding before a compute dispatch, and the
state tracker needs to let the driver known about this.

Fixes GL45-CTS.compute_shader.pipeline-post-fs on SI family Radeons.

Cc: mesa-stable@lists.freedesktop.org

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
(cherry picked from commit 40c77bbf83a369f21c5a95f14417348aae2dbe42)