On Sun, Sep 26, 2021 at 06:14:15PM +0800, Xu Yang wrote:
> USB TCPCI Spec, 4.4.3 Mask Registers:
> "A masked register will still indicate in the ALERT register, but shall
> not set the Alert# pin low."
>
> Thus, the Extended Status will still indicate in ALERT register if vSafe0V
> is detected by TCPC even though being masked. In current code, howerer,
> this event will not be handled in detection time. Rather it will be
> handled when next ALERT event coming(CC evnet, PD event, etc).
>
> Tcpm might transition to a wrong state in this situation. Thus, the vSafe0V
> event should not be handled when it's masked.
>
> Fixes: 766c485b86ef ("usb: typec: tcpci: Add support to report vSafe0V")
> cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 9858716698df..c15eec9cc460 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -696,7 +696,7 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
> tcpm_pd_receive(tcpci->port, &msg);
> }
>
> - if (status & TCPC_ALERT_EXTENDED_STATUS) {
> + if (tcpci->data->vbus_vsafe0v && (status & TCPC_ALERT_EXTENDED_STATUS)) {
> ret = regmap_read(tcpci->regmap, TCPC_EXTENDED_STATUS, &raw);
> if (!ret && (raw & TCPC_EXTENDED_STATUS_VSAFE0V))
> tcpm_vbus_change(tcpci->port);
> --
> 2.25.1
--
heikki
