[PATCH] usb: typec: tcpm: always rediscover when swapping DR
From: Icenowy Zheng
Date: Fri Aug 13 2021 - 00:32:31 EST
Currently, TCPM code omits discover when swapping to gadget, and assume
that no altmodes are available when swapping from gadget. However, we do
send discover when we get attached as gadget -- this leads to modes to be
discovered twice when attached as gadget and then swap to host.
Always re-send discover when swapping DR, regardless of what change is
being made; and because of this, the assumption that no altmodes are
registered with gadget role is broken, and altmodes de-registeration is
always needed now.
Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index b9bb63d749ec..ab6d0d51ee1c 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4495,15 +4495,14 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, ready_state(port), 0);
break;
case DR_SWAP_CHANGE_DR:
- if (port->data_role == TYPEC_HOST) {
- tcpm_unregister_altmodes(port);
+ tcpm_unregister_altmodes(port);
+ if (port->data_role == TYPEC_HOST)
tcpm_set_roles(port, true, port->pwr_role,
TYPEC_DEVICE);
- } else {
+ else
tcpm_set_roles(port, true, port->pwr_role,
TYPEC_HOST);
- port->send_discover = true;
- }
+ port->send_discover = true;
tcpm_ams_finish(port);
tcpm_set_state(port, ready_state(port), 0);
break;
--
2.30.2