[PATCH] usb: typec: tcpm: Fix if vbus before cc, hard_reset_count not reset issue

From: cy_huang
Date: Wed Sep 02 2020 - 11:36:23 EST


From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>

Fix: If vbus event is before cc_event trigger, hard_reset_count
won't bt reset for some case.

Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
---
Below's the flow.

_tcpm_pd_vbus_off() -> run_state_machine to change state to SNK_UNATTACHED
call tcpm_snk_detach() -> tcpm_snk_detach() -> tcpm_detach()
tcpm_port_is_disconnected() will be called.
But port->attached is still true and port->cc1=open and port->cc2=open

It cause tcpm_port_is_disconnected return false, then hard_reset_count won't be reset.
After that, tcpm_reset_port() is called.
port->attached become false.

After that, cc now trigger cc_change event, the hard_reset_count will be kept.
Even tcpm_detach will be called, due to port->attached is false, tcpm_detach()
will directly return.

CC_EVENT will only trigger drp toggling again.
---
drivers/usb/typec/tcpm/tcpm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index a48e3f90..5c73e1d 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -2797,8 +2797,7 @@ static void tcpm_detach(struct tcpm_port *port)
port->tcpc->set_bist_data(port->tcpc, false);
}

- if (tcpm_port_is_disconnected(port))
- port->hard_reset_count = 0;
+ port->hard_reset_count = 0;

tcpm_reset_port(port);
}
--
2.7.4