linux-kernel - [PATCH v1] usb: typec: tcpm: Ignore CC and vbus changes in PORT

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Message-Id: <20200402215947.176577-1-badhri@google.com>
Date:   Thu,  2 Apr 2020 14:59:47 -0700
From:   Badhri Jagan Sridharan <badhri@...gle.com>
To:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        Badhri Jagan Sridharan <badhri@...gle.com>
Subject: [PATCH v1] usb: typec: tcpm: Ignore CC and vbus changes in PORT_RESET change

After PORT_RESET, the port is set to the appropriate
default_state. Ignore processing CC changes here as this
could cause the port to be switched into sink states
by default.

echo source > /sys/class/typec/port0/port_type

Before:
[  154.528547] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms
[  154.528560] CC1: 0 -> 0, CC2: 3 -> 0 [state PORT_RESET, polarity 0, disconnected]
[  154.528564] state change PORT_RESET -> SNK_UNATTACHED

After:
[  151.068814] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev3 NONE_AMS]
[  151.072440] CC1: 3 -> 0, CC2: 0 -> 0 [state PORT_RESET, polarity 0, disconnected]
[  151.172117] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms]
[  151.172136] pending state change PORT_RESET_WAIT_OFF -> SRC_UNATTACHED @ 870 ms [rev3 NONE_AMS]
[  152.060106] state change PORT_RESET_WAIT_OFF -> SRC_UNATTACHED [delayed 870 ms]
[  152.060118] Start toggling

Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index de3576e6530ab2..82b19ebd7838e0 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3794,6 +3794,14 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
 		 */
 		break;
 
+	case PORT_RESET:
+	case PORT_RESET_WAIT_OFF:
+		/*
+		 * State set back to default mode once the timer completes.
+		 * Ignore CC changes here.
+		 */
+		break;
+
 	default:
 		if (tcpm_port_is_disconnected(port))
 			tcpm_set_state(port, unattached_state(port), 0);
@@ -3855,6 +3863,15 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port)
 	case SRC_TRY_DEBOUNCE:
 		/* Do nothing, waiting for sink detection */
 		break;
+
+	case PORT_RESET:
+	case PORT_RESET_WAIT_OFF:
+		/*
+		 * State set back to default mode once the timer completes.
+		 * Ignore vbus changes here.
+		 */
+		break;
+
 	default:
 		break;
 	}
@@ -3908,10 +3925,19 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
 	case PORT_RESET_WAIT_OFF:
 		tcpm_set_state(port, tcpm_default_state(port), 0);
 		break;
+
 	case SRC_TRY_WAIT:
 	case SRC_TRY_DEBOUNCE:
 		/* Do nothing, waiting for sink detection */
 		break;
+
+	case PORT_RESET:
+		/*
+		 * State set back to default mode once the timer completes.
+		 * Ignore vbus changes here.
+		 */
+		break;
+
 	default:
 		if (port->pwr_role == TYPEC_SINK &&
 		    port->attached)
-- 
2.26.0.292.g33ef6b2f38-goog