From 3e7a3e4b4e77f55e14a15158e046215e1a0e5ba1 Mon Sep 17 00:00:00 2001 From: Badhri Jagan Sridharan Date: Fri, 21 Jan 2022 17:55:19 -0800 Subject: [PATCH] usb: typec: tcpm: Do not disconnect while receiving VBUS off commit 90b8aa9f5b09edae6928c0561f933fec9f7a9987 upstream. With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V before tcpm gets to read port->tcpc->get_vbus. This will will report a VBUS off event causing TCPM to transition to SNK_UNATTACHED where it should be waiting in either SNK_ATTACH_WAIT or SNK_DEBOUNCED state. This patch makes TCPM avoid vbus off 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: f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)") Cc: stable@vger.kernel.org Acked-by: Heikki Krogerus Signed-off-by: Badhri Jagan Sridharan Link: https://lore.kernel.org/r/20220122015520.332507-1-badhri@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/typec/tcpm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c index 4fff829b00aa..04734a827593 100644 --- a/drivers/staging/typec/tcpm.c +++ b/drivers/staging/typec/tcpm.c @@ -3103,7 +3103,8 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port) case SNK_TRYWAIT_DEBOUNCE: break; case SNK_ATTACH_WAIT: - tcpm_set_state(port, SNK_UNATTACHED, 0); + case SNK_DEBOUNCED: + /* Do nothing, as TCPM is still waiting for vbus to reaach VSAFE5V to connect */ break; case SNK_NEGOTIATE_CAPABILITIES: -- 2.20.1