drm/amd/display: Disallow enabling CRTC without primary plane with FB
authorHarry Wentland <harry.wentland@amd.com>
Mon, 16 Apr 2018 21:28:11 +0000 (17:28 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Wed, 25 Apr 2018 15:07:49 +0000 (10:07 -0500)
commitf2877656809386d7bc62c2b1c1b4e58404c486d4
treecb168a6df647c3e4e2e553028c5ba8842a9f6b3c
parentad64dc0137968f09800e58174bbfd5eac9fe5418
drm/amd/display: Disallow enabling CRTC without primary plane with FB

The below commit

    "drm/atomic: Try to preserve the crtc enabled state in drm_atomic_remove_fb, v2"

introduces a slight behavioral change to rmfb. Instead of disabling a crtc
when the primary plane is disabled, it now preserves it.

Since DC is currently not equipped to handle this we need to fail such
a commit, otherwise we might see a corrupted screen.

This is based on Shirish's previous approach but avoids adding all
planes to the new atomic state which leads to a full update in DC for
any commit, and is not what we intend.

Theoretically DM should be able to deal with states with fully populated planes,
even for simple updates, such as cursor updates. This should still be
addressed in the future.

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c