From: Fudong Wang Fudong.Wang@amd.com
[ Upstream commit b2a93490201300a749ad261b5c5d05cb50179c44 ]
[Why] After ODM clock off, optc underflow bit will be kept there always and clear not work. We need to clear that before clock off.
[How] Clear that if have when clock off.
Reviewed-by: Alvin Lee alvin.lee2@amd.com Acked-by: Tom Chung chiahsuan.chung@amd.com Signed-off-by: Fudong Wang Fudong.Wang@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c index 800be2693faca..963d72f96dca3 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c @@ -464,6 +464,11 @@ void optc1_enable_optc_clock(struct timing_generator *optc, bool enable) OTG_CLOCK_ON, 1, 1, 1000); } else { + + //last chance to clear underflow, otherwise, it will always there due to clock is off. + if (optc->funcs->is_optc_underflow_occurred(optc) == true) + optc->funcs->clear_optc_underflow(optc); + REG_UPDATE_2(OTG_CLOCK_CONTROL, OTG_CLOCK_GATE_DIS, 0, OTG_CLOCK_EN, 0);