linux/drivers/gpu/drm/amd/display
Anthony Koo 44ab1aa84a drm/amd/display: do not power on eDP power rail early
[Why]
Modern Standby may toggle display adapter state between D0
and D3 state unpredictably.
But events that cause transition to D0 are not always resulting
in a display light up scenario.

Modern eDP panels should be able to power on panel logic
quickly upon VDD going high. Based on spec, the T3 time
between VDD on and HPD high can be between 0 and 80 ms.

Doing any tricky sorts of optimization by powering on panel
VDD early during D0 transition on can negatively impact other
features due to unnecessary power drain and toggling when
final system state does not intend for the panel to be lit up.

We need OEMs to source higher end panels that have T3 time
close to 0 if they want quick S3/Modern Standby resume times.

[How]
Remove panel VDD power on in init_hw

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-05-31 10:39:31 -05:00
..
amdgpu_dm drm/amd/display: Ensure DRR triggers in BP 2019-05-31 10:39:30 -05:00
dc drm/amd/display: do not power on eDP power rail early 2019-05-31 10:39:31 -05:00
include drm/amd/display: make clk mgr soc specific 2019-05-31 10:39:29 -05:00
modules drm/amd/display: Don't use ROM for output TF if GAMMA_CS_TFM_1D 2019-05-31 10:39:29 -05:00
Kconfig Merge branch 'drm-next-5.3' of git://people.freedesktop.org/~agd5f/linux into drm-next 2019-05-31 10:04:39 +10:00
Makefile drm/amd/display: move clk_mgr files to right place 2019-05-31 10:39:31 -05:00
TODO drm/amd/display: Convert remaining loggers off dc_logger 2018-07-13 14:48:42 -05:00