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 6.3-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-6.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0f1588a48c49dc4c7957c8340052ef772b100700 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 b4df540c0c61e..36fa413f8b42e 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 d13e46eeee3c0..6d3f2335b9f1e 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c @@ -285,7 +285,7 @@ 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 823f29c292d05..184310fa52b1a 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c @@ -895,7 +895,7 @@ 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)