From: Dale Zhao <dale.zhao@amd.com> stable inclusion from stable-5.10.56 commit 63570e578094b4f0b6b8c6ac4a68195455733e31 bugzilla: 176004 https://gitee.com/openeuler/kernel/issues/I4DYZ4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit b53e041d8e4308f7324999398aec092dbcb130f5 upstream. [Why] We don't check DENTIST_DISPCLK_CHG_DONE to ensure dentist display clockis updated to target value. In some scenarios with large display clock margin, it will deliver unfinished display clock and cause issues like display black screen. [How] Checking DENTIST_DISPCLK_CHG_DONE to ensure display clock has been update to target value before driver do other clock related actions. Reviewed-by: Cyr Aric <aric.cyr@amd.com> Acked-by: Solomon Chiu <solomon.chiu@amd.com> Signed-off-by: Dale Zhao <dale.zhao@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c index f2114bc910bf..6b744edcd75f 100644 --- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c +++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c @@ -135,7 +135,7 @@ void dcn20_update_clocks_update_dentist(struct clk_mgr_internal *clk_mgr) REG_UPDATE(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_WDIVIDER, dispclk_wdivider); -// REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 5, 100); + REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 50, 1000); REG_UPDATE(DENTIST_DISPCLK_CNTL, DENTIST_DPPCLK_WDIVIDER, dppclk_wdivider); REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DPPCLK_CHG_DONE, 1, 5, 100); -- 2.20.1