From 5a42dc2be09a550777619a29187867d0423c353a Mon Sep 17 00:00:00 2001 From: Zi Yu Liao Date: Thu, 20 Jun 2019 10:55:26 -0400 Subject: [PATCH] drm/amd/display: fix DMCU hang when going into Modern Standby [why] When the system is going into suspend, set_backlight gets called after the eDP got blanked. Since smooth brightness is enabled, the driver will make a call into the DMCU to ramp the brightness. The DMCU would try to enable ABM to do so. But since the display is blanked, this ends up causing ABM1_ACE_DBUF_REG_UPDATE_PENDING to get stuck at 1, which results in a dead lock in the DMCU firmware. [how] Disable brightness ramping when the eDP display is blanked. Signed-off-by: Zi Yu Liao Reviewed-by: Eric Yang Acked-by: Anthony Koo Acked-by: Leo Li Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index d685cde..5852dd5 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -2352,7 +2352,7 @@ bool dc_link_set_backlight_level(const struct dc_link *link, if (core_dc->current_state->res_ctx.pipe_ctx[i].stream) { if (core_dc->current_state->res_ctx. pipe_ctx[i].stream->link - == link) + == link) { /* DMCU -1 for all controller id values, * therefore +1 here */ @@ -2360,6 +2360,13 @@ bool dc_link_set_backlight_level(const struct dc_link *link, core_dc->current_state-> res_ctx.pipe_ctx[i].stream_res.tg->inst + 1; + + /* Disable brightness ramping when the display is blanked + * as it can hang the DMCU + */ + if (core_dc->current_state->res_ctx.pipe_ctx[i].plane_state == NULL) + frame_ramp = 0; + } } } abm->funcs->set_backlight_level_pwm( -- 2.7.4