[PATCH v2 1/4] usb: typec: tcpm: Fix up PR_SWAP when vsafe0v is signalled

[Badhri Jagan Sridharan <badhri@google.com>]

During PR_SWAP, When TCPM is in PR_SWAP_SNK_SRC_SINK_OFF, vbus is
expected to reach VSAFE0V when source turns off vbus. Do not move
to SNK_UNATTACHED state when this happens.

Fixes: 28b43d3d746b ("usb: typec: tcpm: Introduce vsafe0v for vbus")
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
Changes since V1:
- Fixed type s/of/off in commit message.
- Added Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/usb/typec/tcpm/tcpm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index c4fdc00a3bc8..b93c4c8d7b15 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -5114,6 +5114,9 @@ static void _tcpm_pd_vbus_vsafe0v(struct tcpm_port *port)
 				tcpm_set_state(port, SNK_UNATTACHED, 0);
 		}
 		break;
+	case PR_SWAP_SNK_SRC_SINK_OFF:
+		/* Do nothing, vsafe0v is expected during transition */
+		break;
 	default:
 		if (port->pwr_role == TYPEC_SINK && port->auto_vbus_discharge_enabled)
 			tcpm_set_state(port, SNK_UNATTACHED, 0);
-- 
2.31.1.751.gd2f1c929bd-goog