From: Badhri Jagan Sridharan <badhri@google.com>
To: Guenter Roeck <linux@roeck-us.net>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Badhri Jagan Sridharan <badhri@google.com>
Subject: [PATCH v1] usb: typec: tcpm: Update vbus_vsafe0v on init
Date: Thu, 10 Dec 2020 23:19:11 -0800 [thread overview]
Message-ID: <20201211071911.2205197-1-badhri@google.com> (raw)
During init, vbus_vsafe0v does not get updated till the first
connect as a sink. This causes TCPM to be stuck in SRC_ATTACH_WAIT
state while booting with a sink (For instance: a headset) connected.
[ 1.429168] Start toggling
[ 1.439907] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[ 1.445242] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[ 53.358528] CC1: 0 -> 0, CC2: 0 -> 2 [state TOGGLING, polarity 0, connected]
[ 53.358564] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]
Fix this by updating vbus_vsafe0v based on vbus_present status
on boot.
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
drivers/usb/typec/tcpm/tcpm.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index cedc6cf82d61..58a6302c549f 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4794,6 +4794,24 @@ static void tcpm_init(struct tcpm_port *port)
if (port->vbus_present)
port->vbus_never_low = true;
+ /*
+ * 1. When vbus_present is true, voltage on VBUS is already at VSAFE5V.
+ * So implicitly vbus_vsafe0v = false.
+ *
+ * 2. When vbus_present is false and TCPC does NOT support querying
+ * vsafe0v status, then, it's best to assume vbus is at VSAFE0V i.e.
+ * vbus_vsafe0v is true.
+ *
+ * 3. When vbus_present is false and TCPC does support querying vsafe0v,
+ * then, query tcpc for vsafe0v status.
+ */
+ if (port->vbus_present)
+ port->vbus_vsafe0v = false;
+ else if (!port->tcpc->is_vbus_vsafe0v)
+ port->vbus_vsafe0v = true;
+ else
+ port->vbus_vsafe0v = port->tcpc->is_vbus_vsafe0v(port->tcpc);
+
tcpm_set_state(port, tcpm_default_state(port), 0);
if (port->tcpc->get_cc(port->tcpc, &cc1, &cc2) == 0)
--
2.29.2.576.ga3fc446d84-goog
next reply other threads:[~2020-12-11 7:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-11 7:19 Badhri Jagan Sridharan [this message]
2020-12-11 8:43 ` [PATCH v1] usb: typec: tcpm: Update vbus_vsafe0v on init Heikki Krogerus
2020-12-11 15:15 ` Guenter Roeck
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