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 <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>
This commit is contained in:
Zi Yu Liao 2019-06-20 10:55:26 -04:00 committed by Alex Deucher
parent 1d0610bc26
commit 5a42dc2be0

View File

@ -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(