The following applies to the graphics corruption seen in Dolphin:

ea5b7de138bb7e9a4e7e4f0c39c4ceb16acae923 is the first bad commit
commit ea5b7de138bb7e9a4e7e4f0c39c4ceb16acae923
Author: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Date:   Wed Jul 3 19:27:12 2019 +0200

    radeonsi: make gl_SampleMaskIn = 0x1 when MSAA is disabled

    gl_SampleMaskIn is 1 when R_028BE0_PA_SC_AA_CONFIG is 0, so this commit
rework the conditions
    controlling this register.

    Before it was set if the sctx->framebuffer had a sample count > 1.

    Now we still require this condition, but we also need either:
      - GL_MULTISAMPLE to be enabled
      - to be executing an operation that doesn't depends on GL state using
u_blitter.

    This fixes the arb_sample_shading/sample_mask piglit tests on radeonsi.

    Signed-off-by: Marek Olšák <marek.olsak@amd.com>

 src/gallium/drivers/radeonsi/si_state.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)