From: Zi Yu Liao ziyu.liao@amd.com

[ Upstream commit 1ca068ed34d6b39d336c1b0d618ed73ba8f04548 ]

[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 ziyu.liao@amd.com Reviewed-by: Eric Yang eric.yang2@amd.com Acked-by: Anthony Koo Anthony.Koo@amd.com Acked-by: Leo Li sunpeng.li@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a3ff33ff6da16..adf39e3b8d29d 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -2284,7 +2284,7 @@ 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 */ @@ -2292,6 +2292,13 @@ 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(