On Sun, Aug 20, 2023 at 04:44:48AM +0000, Badhri Jagan Sridharan wrote:
> When partner does not support get_status message, tcpm right now
> responds with soft reset message. This causes PD renegotiation to
> happen and resets PPS link. Avoid soft resetting the link when
> partner does not support get_status message to mitigate PPS resets.
>
> [ 208.926752] Setting voltage/current limit 9500 mV 2450 mA
> [ 208.930407] set_auto_vbus_discharge_threshold mode:3 pps_active:y vbus:9500 ret:0
> [ 208.930418] state change SNK_TRANSITION_SINK -> SNK_READY [rev3 POWER_NEGOTIATION]
> [ 208.930455] AMS POWER_NEGOTIATION finished
>
> // ALERT message from the Source
> [ 213.948442] PD RX, header: 0x19a6 [1]
> [ 213.948451] state change SNK_READY -> GET_STATUS_SEND [rev3 GETTING_SOURCE_SINK_STATUS]
> [ 213.948457] PD TX, header: 0x492
> [ 213.950402] PD TX complete, status: 0
> [ 213.950427] pending state change GET_STATUS_SEND -> GET_STATUS_SEND_TIMEOUT @ 60 ms [rev3 GETTING_SOURCE_SINK_STATUS]
>
> // NOT_SUPPORTED from the Source
> [ 213.959954] PD RX, header: 0xbb0 [1]
>
> // sink sends SOFT_RESET
> [ 213.959958] state change GET_STATUS_SEND -> SNK_SOFT_RESET [rev3 GETTING_SOURCE_SINK_STATUS]
> [ 213.959962] AMS GETTING_SOURCE_SINK_STATUS finished
> [ 213.959964] AMS SOFT_RESET_AMS start
> [ 213.959966] state change SNK_SOFT_RESET -> AMS_START [rev3 SOFT_RESET_AMS]
> [ 213.959969] state change AMS_START -> SOFT_RESET_SEND [rev3 SOFT_RESET_AMS]
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 8dea75e11380 ("usb: typec: tcpm: Protocol Error handling")
> Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 5639b9a1e0bf..280ce1bd7b53 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -2753,6 +2753,13 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
> port->sink_cap_done = true;
> tcpm_set_state(port, ready_state(port), 0);
> break;
> + /*
> + * Some port partners do not support GET_STATUS, avoid soft reset the link to
> + * prevent redundant power re-negotiation
> + */
> + case GET_STATUS_SEND:
> + tcpm_set_state(port, ready_state(port), 0);
> + break;
> case SRC_READY:
> case SNK_READY:
> if (port->vdm_state > VDM_STATE_READY) {
>
> base-commit: bbb9e06d2c6435af9c62074ad7048910eeb2e7bc
> --
> 2.42.0.rc1.204.g551eb34607-goog
--
heikki
