From: TungYu Lu Date: Tue, 15 Jul 2025 08:56:59 +0000 (+0800) Subject: drm/amd/display: Wait until OTG enable state is cleared X-Git-Tag: v6.12.58~374 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ffd2a2cdbbbbca72237f22032535ee8059cd55b;p=thirdparty%2Fkernel%2Fstable.git drm/amd/display: Wait until OTG enable state is cleared [ Upstream commit e7496c15d830689cc4fc666b976c845ed2c5ed28 ] [Why] Customer reported an issue that OS starts and stops device multiple times during driver installation. Frequently disabling and enabling OTG may prevent OTG from being safely disabled and cause incorrect configuration upon the next enablement. [How] Add a wait until OTG_CURRENT_MASTER_EN_STATE is cleared as a short term solution. Reviewed-by: Dillon Varone Signed-off-by: TungYu Lu Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- diff --git a/drivers/gpu/drm/amd/display/dc/optc/dcn401/dcn401_optc.c b/drivers/gpu/drm/amd/display/dc/optc/dcn401/dcn401_optc.c index a5d6a7dca554c..27a9ec55d53ec 100644 --- a/drivers/gpu/drm/amd/display/dc/optc/dcn401/dcn401_optc.c +++ b/drivers/gpu/drm/amd/display/dc/optc/dcn401/dcn401_optc.c @@ -226,6 +226,11 @@ static bool optc401_disable_crtc(struct timing_generator *optc) REG_UPDATE(CONTROL, VTG0_ENABLE, 0); + // wait until CRTC_CURRENT_MASTER_EN_STATE == 0 + REG_WAIT(OTG_CONTROL, + OTG_CURRENT_MASTER_EN_STATE, + 0, 10, 15000); + /* CRTC disabled, so disable clock. */ REG_WAIT(OTG_CLOCK_CONTROL, OTG_BUSY, 0,