Re: [PATCH v1] usb: typec: tcpm: Update vbus_vsafe0v on init
From: Heikki Krogerus
Date: Fri Dec 11 2020 - 03:45:49 EST
On Thu, Dec 10, 2020 at 11:19:11PM -0800, Badhri Jagan Sridharan wrote:
> During init, vbus_vsafe0v does not get updated till the first
> connect as a sink. This causes TCPM to be stuck in SRC_ATTACH_WAIT
> state while booting with a sink (For instance: a headset) connected.
>
> [ 1.429168] Start toggling
> [ 1.439907] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 1.445242] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 53.358528] CC1: 0 -> 0, CC2: 0 -> 2 [state TOGGLING, polarity 0, connected]
> [ 53.358564] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]
>
> Fix this by updating vbus_vsafe0v based on vbus_present status
> on boot.
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
One nitpick bellow, but it's so minor that you can ignore it if you
like. FWIW:
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index cedc6cf82d61..58a6302c549f 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -4794,6 +4794,24 @@ static void tcpm_init(struct tcpm_port *port)
> if (port->vbus_present)
> port->vbus_never_low = true;
>
> + /*
> + * 1. When vbus_present is true, voltage on VBUS is already at VSAFE5V.
> + * So implicitly vbus_vsafe0v = false.
> + *
> + * 2. When vbus_present is false and TCPC does NOT support querying
> + * vsafe0v status, then, it's best to assume vbus is at VSAFE0V i.e.
> + * vbus_vsafe0v is true.
> + *
> + * 3. When vbus_present is false and TCPC does support querying vsafe0v,
> + * then, query tcpc for vsafe0v status.
> + */
> + if (port->vbus_present)
> + port->vbus_vsafe0v = false;
> + else if (!port->tcpc->is_vbus_vsafe0v)
> + port->vbus_vsafe0v = true;
> + else
> + port->vbus_vsafe0v = port->tcpc->is_vbus_vsafe0v(port->tcpc);
Couldn't that be the other way around?
...
else if (port->tcpc->is_vbus_vsafe0v)
port->vbus_vsafe0v = port->tcpc->is_vbus_vsafe0v(port->tcpc);
else
port->vbus_vsafe0v = true;
...
> tcpm_set_state(port, tcpm_default_state(port), 0);
>
> if (port->tcpc->get_cc(port->tcpc, &cc1, &cc2) == 0)
> --
> 2.29.2.576.ga3fc446d84-goog
thanks,
--
heikki