[PATCH v1] usb: typec: tcpm: clear pd_event queue in PORT_RESET

[PATCH v1] usb: typec: tcpm: clear pd_event queue in PORT_RESET

[RD Babiera]

When a Fast Role Swap control message attempt results in a transition
to ERROR_RECOVERY, the TCPC can still queue a TCPM_SOURCING_VBUS event.

If the event is queued but processed after the tcpm_reset_port() call
in the PORT_RESET state, then the following occurs:
1. tcpm_reset_port() calls tcpm_init_vbus() to reset the vbus sourcing and
sinking state
2. tcpm_pd_event_handler() turns VBUS on before the port is in the default
state.
3. The port resolves as a sink. In the SNK_DISCOVERY state,
tcpm_set_charge() cannot set vbus to charge.

Clear pd events within PORT_RESET to get rid of non-applicable events.

Fixes: b17dd57118fe ("staging: typec: tcpm: Improve role swap with non PD capable partners")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index c26fb70c3ec6..6dcafbaf10a2 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -5605,6 +5605,7 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case PORT_RESET:
 		tcpm_reset_port(port);
+		port->pd_events = 0;
 		if (port->self_powered)
 			tcpm_set_cc(port, TYPEC_CC_OPEN);
 		else

base-commit: 684e9f5f97eb4b7831298ffad140d5c1d426ff27
-- 
2.44.0.769.g3c40516874-goog

Re: [PATCH v1] usb: typec: tcpm: clear pd_event queue in PORT_RESET

[Heikki Krogerus]

On Tue, Apr 23, 2024 at 08:27:16PM +0000, RD Babiera wrote:
> When a Fast Role Swap control message attempt results in a transition
> to ERROR_RECOVERY, the TCPC can still queue a TCPM_SOURCING_VBUS event.
> 
> If the event is queued but processed after the tcpm_reset_port() call
> in the PORT_RESET state, then the following occurs:
> 1. tcpm_reset_port() calls tcpm_init_vbus() to reset the vbus sourcing and
> sinking state
> 2. tcpm_pd_event_handler() turns VBUS on before the port is in the default
> state.
> 3. The port resolves as a sink. In the SNK_DISCOVERY state,
> tcpm_set_charge() cannot set vbus to charge.
> 
> Clear pd events within PORT_RESET to get rid of non-applicable events.
> 
> Fixes: b17dd57118fe ("staging: typec: tcpm: Improve role swap with non PD capable partners")
> Cc: stable@vger.kernel.org
> Signed-off-by: RD Babiera <rdbabiera@google.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/tcpm/tcpm.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index c26fb70c3ec6..6dcafbaf10a2 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -5605,6 +5605,7 @@ static void run_state_machine(struct tcpm_port *port)
>  		break;
>  	case PORT_RESET:
>  		tcpm_reset_port(port);
> +		port->pd_events = 0;
>  		if (port->self_powered)
>  			tcpm_set_cc(port, TYPEC_CC_OPEN);
>  		else
> 
> base-commit: 684e9f5f97eb4b7831298ffad140d5c1d426ff27
> -- 
> 2.44.0.769.g3c40516874-goog

-- 
heikki