usb: typec: tcpm: Disregard vbus off while in PR_SWAP_SNK_SRC_SOURCE_ON

During PR_SWAP sequence, when TCPM is waiting in PR_SWAP_SNK_SRC_SOURCE_ON
for the vbus source to ramp up, TCPM would prematurely exit
PR_SWAP_SNK_SRC_SOURCE_ON and transition to SNK_UNATTACHED state when a
vbus off notification is received. This should not be the case as vbus
can still be off while in PR_SWAP_SNK_SRC_SOURCE_ON and the vbus source
has PD_T_NEWSRC to ramp up.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20201125020703.1604979-1-badhri@google.com
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 4aac0ef..277b9d4 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4218,6 +4218,14 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
                /* Do nothing, expected */
                break;
 
+       case PR_SWAP_SNK_SRC_SOURCE_ON:
+               /*
+                * Do nothing when vbus off notification is received.
+                * TCPM can wait for PD_T_NEWSRC in PR_SWAP_SNK_SRC_SOURCE_ON
+                * for the vbus source to ramp up.
+                */
+               break;
+
        case PORT_RESET_WAIT_OFF:
                tcpm_set_state(port, tcpm_default_state(port), 0);
                break;