From: Badhri Jagan Sridharan badhri@google.com
commit 746f96e7d6f7a276726860f696671766bfb24cf0 upstream.
With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V causing VSAFE0V to be triggered. This will will report a VBUS off event causing TCPM to transition to SNK_UNATTACHED state where it should be waiting in either SNK_ATTACH_WAIT or SNK_DEBOUNCED state. This patch makes TCPM avoid VSAFE0V events while in SNK_ATTACH_WAIT or SNK_DEBOUNCED state.
Stub from the spec: "4.5.2.2.4.2 Exiting from AttachWait.SNK State A Sink shall transition to Unattached.SNK when the state of both the CC1 and CC2 pins is SNK.Open for at least tPDDebounce. A DRP shall transition to Unattached.SRC when the state of both the CC1 and CC2 pins is SNK.Open for at least tPDDebounce."
[23.194131] CC1: 0 -> 0, CC2: 0 -> 5 [state SNK_UNATTACHED, polarity 0, connected] [23.201777] state change SNK_UNATTACHED -> SNK_ATTACH_WAIT [rev3 NONE_AMS] [23.209949] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS] [23.300579] VBUS off [23.300668] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [rev3 NONE_AMS] [23.301014] VBUS VSAFE0V [23.301111] Start toggling
Fixes: 28b43d3d746b8 ("usb: typec: tcpm: Introduce vsafe0v for vbus") Cc: stable@vger.kernel.org Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com Signed-off-by: Badhri Jagan Sridharan badhri@google.com Link: https://lore.kernel.org/r/20220122015520.332507-2-badhri@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/tcpm/tcpm.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -5264,6 +5264,10 @@ static void _tcpm_pd_vbus_vsafe0v(struct case PR_SWAP_SNK_SRC_SOURCE_ON: /* Do nothing, vsafe0v is expected during transition */ break; + case SNK_ATTACH_WAIT: + case SNK_DEBOUNCED: + /*Do nothing, still waiting for VSAFE5V for connect */ + break; default: if (port->pwr_role == TYPEC_SINK && port->auto_vbus_discharge_enabled) tcpm_set_state(port, SNK_UNATTACHED, 0);