From: Fudong Wang <Fudong.Wang@amd.com> stable inclusion from stable-v4.19.257 commit 443687798d6f094412b7312b64b3bb4d99aedff7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICG9B8 CVE: CVE-2022-49969 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Lin Ruifeng <linruifeng4@huawei.com> --- 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 411f89218e01..cb5c44b339e0 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c @@ -452,6 +452,11 @@ 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); -- 2.22.0