From 7c70e60fbf4bff1123f0e8d5cb1ae71df6164d7f Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Wed, 29 May 2024 12:12:09 -0400 Subject: [PATCH] drm/amd/display: Disable DMCUB timeout for DCN35 [Why] DMCUB can intermittently take longer than expected to process commands. Old ASIC policy was to continue while logging a diagnostic error - which works fine for ASIC without IPS, but with IPS this could lead to a race condition where we attempt to access DCN state while it's inaccessible, leading to a system hang when the NIU port is not disabled or register accesses that timeout and the display configuration in an undefined state. [How] We need to investigate why these accesses take longer than expected, but for now we should disable the timeout on DCN35 to avoid this race condition. Since the waits happen only at lower interrupt levels the risk of taking too long at higher IRQ and causing a system watchdog timeout are minimal. Reviewed-by: Ovidiu Bunea Acked-by: Zaeem Mohamed Signed-off-by: Nicholas Kazlauskas Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c index 391f9f69a923..5edccd565b05 100644 --- a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c @@ -785,6 +785,7 @@ static const struct dc_debug_options debug_defaults_drv = { .ips2_entry_delay_us = 800, .disable_dmub_reallow_idle = false, .static_screen_wait_frames = 2, + .disable_timeout = true, }; static const struct dc_panel_config panel_config_defaults = { -- 2.50.1