drm/amd/display: Fix takover from VGA mode
HW Engineer's Notes:
During switch from vga->extended, if we set the VGA_TEST_ENABLE and then
hit the VGA_TEST_RENDER_START, then the DCHUBP timing gets updated correctly.
Then vBIOS will have it poll for the VGA_TEST_RENDER_DONE and unset
VGA_TEST_ENABLE, to leave it in the same state as before.
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2 files changed