usb: typec: tcpm: Do not disconnect while receiving VBUS off

PATCH Superseded Badhri Jagan Sridharan 2 participants 4 messages Jan 26, 2022

Subsystems (4)

Stable branch USB USB Type-C class USB Type-C port controller drivers

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Badhri Jagan Sridharan

author maintainer

2022-01-26 02:00 UTC #0 lore raw

PATCH v2 1/2 usb: typec: tcpm: Do not disconnect while receiving VBUS off

With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V before tcpm gets to read port->tcpc->get_vbus. This will report a VBUS off event causing TCPM to transition to SNK_UNATTACHED where it should be waiting in either SNK_ATTACH_WAIT or SNK_DEBOUNCED state. This patch makes TCPM avoid vbus off 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 f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)")

Cc [email protected]

Signed-off-by Badhri Jagan Sridharan <[email protected]>

---
Changes since v1:
- Fix typos stated by Guenter Roeck.

---
 drivers/usb/typec/tcpm/tcpm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

drivers/usb/typec/tcpm/tcpm.c +2 -1

index 59d4fa2443f2..3bf79f52bd34 100644
@@ -5156,7 +5156,8 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
 	case SNK_TRYWAIT_DEBOUNCE:
 		break;
 	case SNK_ATTACH_WAIT:
-		tcpm_set_state(port, SNK_UNATTACHED, 0);
+	case SNK_DEBOUNCED:
+		/* Do nothing, as TCPM is still waiting for vbus to reach VSAFE5V to connect */
 		break;
 
 	case SNK_NEGOTIATE_CAPABILITIES:

Signature · 1 line

2.35.0.rc0.227.g00780c9af4-goog

Badhri Jagan Sridharan

author maintainer

2022-01-26 02:00 UTC #1 lore raw

PATCH v2 2/2 usb: typec: tcpm: Do not disconnect when receiving VSAFE0V

With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V causing VSAFE0V to be triggered. This 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.

[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 f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)")

Cc [email protected]

Signed-off-by Badhri Jagan Sridharan <[email protected]>

---
Changes since v1:
- Fix typos stated by Guenter Roeck.

---
 drivers/usb/typec/tcpm/tcpm.c | 4 ++++
 1 file changed, 4 insertions(+)

drivers/usb/typec/tcpm/tcpm.c +4 -0

index 3bf79f52bd34..0e0985355a14 100644
@@ -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 to connect */
+		break;
 	default:
 		if (port->pwr_role == TYPEC_SINK && port->auto_vbus_discharge_enabled)
 			tcpm_set_state(port, SNK_UNATTACHED, 0);

Signature · 1 line

2.35.0.rc0.227.g00780c9af4-goog

Guenter Roeck

2022-01-26 03:34 UTC #2 lore raw

In reply to Badhri Jagan Sridharan

Quoted 22 lines · Badhri Jagan Sridharan

With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V before tcpm gets to read port->tcpc->get_vbus. This will report a VBUS off event causing TCPM to transition to SNK_UNATTACHED where it should be waiting in either SNK_ATTACH_WAIT or SNK_DEBOUNCED state. This patch makes TCPM avoid vbus off 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

Quoted 3 lines

Fixes f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)")
Cc [email protected]
Signed-off-by Badhri Jagan Sridharan <[email protected]>

Why did you drop the Reviewed-by/Acked-by tags ?

Guenter

Quoted 21 lines

---
Changes since v1:
- Fix typos stated by Guenter Roeck.

---
  drivers/usb/typec/tcpm/tcpm.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

drivers/usb/typec/tcpm/tcpm.c +2 -1

index 59d4fa2443f2..3bf79f52bd34 100644
@@ -5156,7 +5156,8 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
  	case SNK_TRYWAIT_DEBOUNCE:
  		break;
  	case SNK_ATTACH_WAIT:
-		tcpm_set_state(port, SNK_UNATTACHED, 0);
+	case SNK_DEBOUNCED:
+		/* Do nothing, as TCPM is still waiting for vbus to reach VSAFE5V to connect */
  		break;
 
  	case SNK_NEGOTIATE_CAPABILITIES:

Badhri Jagan Sridharan

author maintainer

2022-01-26 04:08 UTC #3 lore raw

My bad ! Apologies .. fixing it in V3..

Quoted 54 lines · Guenter Roeck

Quoted 22 lines · Badhri Jagan Sridharan
With some chargers, vbus might momentarily raise above VSAFE5V and fall back to 0V before tcpm gets to read port->tcpc->get_vbus. This will report a VBUS off event causing TCPM to transition to SNK_UNATTACHED where it should be waiting in either SNK_ATTACH_WAIT or SNK_DEBOUNCED state. This patch makes TCPM avoid vbus off 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
Quoted 3 lines
Fixes f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)")
Cc [email protected]
Signed-off-by Badhri Jagan Sridharan <[email protected]>
Why did you drop the Reviewed-by/Acked-by tags ?
Guenter
Quoted 21 lines
---
Changes since v1:
- Fix typos stated by Guenter Roeck.
---
  drivers/usb/typec/tcpm/tcpm.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)
drivers/usb/typec/tcpm/tcpm.c +2 -1
index 59d4fa2443f2..3bf79f52bd34 100644
@@ -5156,7 +5156,8 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
      case SNK_TRYWAIT_DEBOUNCE:
              break;
      case SNK_ATTACH_WAIT:
-             tcpm_set_state(port, SNK_UNATTACHED, 0);
+     case SNK_DEBOUNCED:
+             /* Do nothing, as TCPM is still waiting for vbus to reach VSAFE5V to connect */
              break;
 
      case SNK_NEGOTIATE_CAPABILITIES: