diff options
Diffstat (limited to 'board/nocturne/usb_pd_policy.c')
| -rw-r--r-- | board/nocturne/usb_pd_policy.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/board/nocturne/usb_pd_policy.c b/board/nocturne/usb_pd_policy.c index 1ee6b8a3b6..1c45ee69e8 100644 --- a/board/nocturne/usb_pd_policy.c +++ b/board/nocturne/usb_pd_policy.c @@ -277,6 +277,21 @@ static void svdm_safe_dp_mode(int port) static int svdm_enter_dp_mode(int port, uint32_t mode_caps) { + /* + * Don't enter the mode if the SoC is off. + * + * There's no need to enter the mode while the SoC is off; we'll + * actually enter the mode on the chipset resume hook. Entering DP Alt + * Mode twice will confuse some monitors and require and unplug/replug + * to get them to work again. The DP Alt Mode on USB-C spec says that + * if we don't need to maintain HPD connectivity info in a low power + * mode, then we shall exit DP Alt Mode. (This is why we don't enter + * when the SoC is off as opposed to suspend where adding a display + * could cause a wake up.) + */ + if (chipset_in_state(CHIPSET_STATE_ANY_OFF)) + return -1; + /* Only enter mode if device is DFP_D capable */ if (mode_caps & MODE_DP_SNK) { svdm_safe_dp_mode(port); |