diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c index 7b959fa2351e..f07a8a3d5c25 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c @@ -242,6 +242,16 @@ static void disable_vga( REG_WRITE(D2VGA_CONTROL, 0); REG_WRITE(D3VGA_CONTROL, 0); REG_WRITE(D4VGA_CONTROL, 0); + + /* 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. + */ + REG_UPDATE(VGA_TEST_CONTROL, VGA_TEST_ENABLE, 1); + REG_UPDATE(VGA_TEST_CONTROL, VGA_TEST_RENDER_START, 1); } static void dpp_pg_control( |