[PATCH v4] usb: typec: tcpm: fix create duplicate source-capabilities file

[Xu Yang <xu.yang_2@nxp.com>]

The kernel will dump in the below cases:
sysfs: cannot create duplicate filename
'/devices/virtual/usb_power_delivery/pd1/source-capabilities'

1. After soft reset has completed, an Explicit Contract negotiation occurs.
The sink device will receive source capabilitys again. This will cause
a duplicate source-capabilities file be created.
2. Power swap twice on a device that is initailly sink role.

This will unregister existing capabilities when above cases occurs.

Fixes: 8203d26905ee ("usb: typec: tcpm: Register USB Power Delivery Capabilities")
cc: <stable@vger.kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
changelogs:
v2: unregister existing capabilities on specific cases
v3: add changelog and modify commit message
v4: reset port->partner_source_caps to NULL
---
 drivers/usb/typec/tcpm/tcpm.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index a0d943d78580..7f39cb9b3429 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4570,6 +4570,9 @@ static void run_state_machine(struct tcpm_port *port)
 	case SOFT_RESET:
 		port->message_id = 0;
 		port->rx_msgid = -1;
+		/* remove existing capabilities */
+		usb_power_delivery_unregister_capabilities(port->partner_source_caps);
+		port->partner_source_caps = NULL;
 		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
 		tcpm_ams_finish(port);
 		if (port->pwr_role == TYPEC_SOURCE) {
@@ -4589,6 +4592,9 @@ static void run_state_machine(struct tcpm_port *port)
 	case SOFT_RESET_SEND:
 		port->message_id = 0;
 		port->rx_msgid = -1;
+		/* remove existing capabilities */
+		usb_power_delivery_unregister_capabilities(port->partner_source_caps);
+		port->partner_source_caps = NULL;
 		if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET))
 			tcpm_set_state_cond(port, hard_reset_state(port), 0);
 		else
@@ -4718,6 +4724,9 @@ static void run_state_machine(struct tcpm_port *port)
 		tcpm_set_state(port, SNK_STARTUP, 0);
 		break;
 	case PR_SWAP_SNK_SRC_SINK_OFF:
+		/* will be source, remove existing capabilities */
+		usb_power_delivery_unregister_capabilities(port->partner_source_caps);
+		port->partner_source_caps = NULL;
 		/*
 		 * Prevent vbus discharge circuit from turning on during PR_SWAP
 		 * as this is not a disconnect.
-- 
2.34.1