diff mbox series

[v1,2/2] usb: typec: tcpm: Do not disconnect when receiving VSAFE0V

Message ID 20220122015520.332507-2-badhri@google.com
State Superseded
Headers show
Series [v1,1/2] usb: typec: tcpm: Do not disconnect while receiving VBUS off | expand

Commit Message

Badhri Jagan Sridharan Jan. 22, 2022, 1:55 a.m. UTC
With some chargers, vbus might momentarily raise above VSAFE5V and fall
back to 0V causing VSAFE0V to be triggered. This will
will report a VBUS off event causing TCPM to transition to
SNK_UNATTACHED state where it should be waiting in either SNK_ATTACH_WAIT
or SNK_DEBOUNCED state. This patch makes TCPM avoid VSAFE0V events
while in SNK_ATTACH_WAIT or SNK_DEBOUNCED state.

Stub from the spec:
    "4.5.2.2.4.2 Exiting from AttachWait.SNK State
    A Sink shall transition to Unattached.SNK when the state of both
    the CC1 and CC2 pins is SNK.Open for at least tPDDebounce.
    A DRP shall transition to Unattached.SRC when the state of both
    the CC1 and CC2 pins is SNK.Open for at least tPDDebounce."

[23.194131] CC1: 0 -> 0, CC2: 0 -> 5 [state SNK_UNATTACHED, polarity 0, connected]
[23.201777] state change SNK_UNATTACHED -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
[23.209949] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
[23.300579] VBUS off
[23.300668] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [rev3 NONE_AMS]
[23.301014] VBUS VSAFE0V
[23.301111] Start toggling

Fixes: 28b43d3d746b8 ("usb: typec: tcpm: Introduce vsafe0v for vbus")
Cc: stable@vger.kernel.org
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Guenter Roeck Jan. 25, 2022, 5:44 p.m. UTC | #1
On 1/21/22 17:55, Badhri Jagan Sridharan wrote:
> With some chargers, vbus might momentarily raise above VSAFE5V and fall
> back to 0V causing VSAFE0V to be triggered. This will
> will report a VBUS off event causing TCPM to transition to

s/will will/will/

> SNK_UNATTACHED state where it should be waiting in either SNK_ATTACH_WAIT
> or SNK_DEBOUNCED state. This patch makes TCPM avoid VSAFE0V events
> while in SNK_ATTACH_WAIT or SNK_DEBOUNCED state.
> 
> Stub from the spec:
>      "4.5.2.2.4.2 Exiting from AttachWait.SNK State
>      A Sink shall transition to Unattached.SNK when the state of both
>      the CC1 and CC2 pins is SNK.Open for at least tPDDebounce.
>      A DRP shall transition to Unattached.SRC when the state of both
>      the CC1 and CC2 pins is SNK.Open for at least tPDDebounce."
> 
> [23.194131] CC1: 0 -> 0, CC2: 0 -> 5 [state SNK_UNATTACHED, polarity 0, connected]
> [23.201777] state change SNK_UNATTACHED -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
> [23.209949] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
> [23.300579] VBUS off
> [23.300668] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [rev3 NONE_AMS]
> [23.301014] VBUS VSAFE0V
> [23.301111] Start toggling
> 
> Fixes: 28b43d3d746b8 ("usb: typec: tcpm: Introduce vsafe0v for vbus")
> Cc: stable@vger.kernel.org
> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> ---
>   drivers/usb/typec/tcpm/tcpm.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index b8afe3d8c882..5fce795b69c7 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -5264,6 +5264,10 @@ static void _tcpm_pd_vbus_vsafe0v(struct tcpm_port *port)
>   	case PR_SWAP_SNK_SRC_SOURCE_ON:
>   		/* Do nothing, vsafe0v is expected during transition */
>   		break;
> +	case SNK_ATTACH_WAIT:
> +	case SNK_DEBOUNCED:
> +		/*Do nothing, still waiting for VSAFE5V for connect */

Space before Do

s/for connect/to connect/, maybe ?

Other than that,

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> +		break;
>   	default:
>   		if (port->pwr_role == TYPEC_SINK && port->auto_vbus_discharge_enabled)
>   			tcpm_set_state(port, SNK_UNATTACHED, 0);
diff mbox series

Patch

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index b8afe3d8c882..5fce795b69c7 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -5264,6 +5264,10 @@  static void _tcpm_pd_vbus_vsafe0v(struct tcpm_port *port)
 	case PR_SWAP_SNK_SRC_SOURCE_ON:
 		/* Do nothing, vsafe0v is expected during transition */
 		break;
+	case SNK_ATTACH_WAIT:
+	case SNK_DEBOUNCED:
+		/*Do nothing, still waiting for VSAFE5V for connect */
+		break;
 	default:
 		if (port->pwr_role == TYPEC_SINK && port->auto_vbus_discharge_enabled)
 			tcpm_set_state(port, SNK_UNATTACHED, 0);