From 3cdaeb85ed1e2e9962361e9b95142cfa1497d300 Mon Sep 17 00:00:00 2001 From: Badhri Jagan Sridharan Date: Fri, 21 Jan 2022 17:55:20 -0800 Subject: [PATCH] usb: typec: tcpm: Do not disconnect when receiving VSAFE0V 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 Signed-off-by: Badhri Jagan Sridharan Link: https://lore.kernel.org/r/20220122015520.332507-2-badhri@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/tcpm/tcpm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index b8afe3d8c882..5fce795b69c7 100644 --- 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 tcpm_port *port) 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); -- 2.34.1