This is a note to let you know that I've just added the patch titled drm/amd/display: fixed dcn30+ underflow issue to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-fixed-dcn30-underflow-issue.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b502792d5325ad72089da19248528cab25803e0d Author: Ayush Gupta <ayugupta@xxxxxxx> Date: Thu Mar 16 15:57:30 2023 -0400 drm/amd/display: fixed dcn30+ underflow issue [ Upstream commit 37403ced9f2873fab7f39ab4ac963bbb33fb0bc0 ] [Why] Observing underflow on dcn30+ system config at 4k144hz [How] We set the UCLK hardmax on AC/DC switch if softmax is enabled and also on boot. While booting up the UCLK Hardmax is set to softmax before the init sequence and the init sequence resets the hardmax to UCLK max which enables P-state switching. Just added a conditional check to avoid setting hardmax on init. Reviewed-by: Alvin Lee <Alvin.Lee2@xxxxxxx> Reviewed-by: Martin Leung <Martin.Leung@xxxxxxx> Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx> Signed-off-by: Ayush Gupta <ayugupta@xxxxxxx> Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c index c20e9f76f0213..a1b312483d7f1 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c @@ -629,7 +629,8 @@ void dcn30_init_hw(struct dc *dc) if (dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr); - if (dc->clk_mgr->funcs->set_hard_max_memclk) + //if softmax is enabled then hardmax will be set by a different call + if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr); if (dc->res_pool->hubbub->funcs->force_pstate_change_control) diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c index bdf101547484a..d4ee533deff32 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c @@ -284,7 +284,7 @@ void dcn31_init_hw(struct dc *dc) if (dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr); - if (dc->clk_mgr->funcs->set_hard_max_memclk) + if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr); if (dc->res_pool->hubbub->funcs->force_pstate_change_control) diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c index e9188bce62e0b..2f4afe40f3e68 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c @@ -970,7 +970,7 @@ void dcn32_init_hw(struct dc *dc) if (dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr); - if (dc->clk_mgr->funcs->set_hard_max_memclk) + if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr); if (dc->res_pool->hubbub->funcs->force_pstate_change_control)