linux-kernel - [PATCH 5.6 151/167] usb: typec: tcpm: Ignore CC and vbus changes in PORT

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Date:   Tue, 28 Apr 2020 20:25:27 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Badhri Jagan Sridharan <badhri@...gle.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 5.6 151/167] usb: typec: tcpm: Ignore CC and vbus changes in PORT_RESET change

From: Badhri Jagan Sridharan <badhri@...gle.com>

commit 901789745a053286e0ced37960d44fa60267b940 upstream.

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>
Cc: stable <stable@...r.kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Reviewed-by: Guenter Roeck <linux@...ck-us.net>
Link: https://lore.kernel.org/r/20200402215947.176577-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/usb/typec/tcpm/tcpm.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3759,6 +3759,14 @@ static void _tcpm_cc_change(struct tcpm_
 		 */
 		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);
@@ -3820,6 +3828,15 @@ static void _tcpm_pd_vbus_on(struct tcpm
 	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;
 	}
@@ -3873,10 +3890,19 @@ static void _tcpm_pd_vbus_off(struct tcp
 	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)