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tcpm: Avoid soft reset when partner does not support get_status

PATCH In review Badhri Jagan Sridharan 3 participants 3 messages Aug 20, 2023 – Aug 23, 2023

Subsystems (4)
Stable branch USB USB Type-C class USB Type-C port controller drivers
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Badhri Jagan Sridharan

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#0 lore raw

PATCH 1/1 tcpm: Avoid soft reset when partner does not support get_status

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 [email protected]
Fixes 8dea75e11380 ("usb: typec: tcpm: Protocol Error handling")
Signed-off-by Badhri Jagan Sridharan <[email protected]>
---
 drivers/usb/typec/tcpm/tcpm.c | 7 +++++++
 1 file changed, 7 insertions(+)
drivers/usb/typec/tcpm/tcpm.c +7 -0
index 5639b9a1e0bf..280ce1bd7b53 100644
@@ -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

Signature · 1 line
2.42.0.rc1.204.g551eb34607-goog
maintainer Acked-by on v1 1/1
#1 lore raw
Quoted 27 lines · Badhri Jagan Sridharan

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]
Quoted 3 lines
Cc [email protected]
Fixes 8dea75e11380 ("usb: typec: tcpm: Protocol Error handling")
Signed-off-by Badhri Jagan Sridharan <[email protected]>
Acked-by Heikki Krogerus <[email protected]>
Quoted 26 lines
---
 drivers/usb/typec/tcpm/tcpm.c | 7 +++++++
 1 file changed, 7 insertions(+)
drivers/usb/typec/tcpm/tcpm.c +7 -0
index 5639b9a1e0bf..280ce1bd7b53 100644
@@ -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

Signature · 1 line
2.42.0.rc1.204.g551eb34607-goog
Signature · 1 line
heikki
Reviewed-by on v1 1/1
#2 lore raw
In reply to Badhri Jagan Sridharan
Quoted 27 lines · Badhri Jagan Sridharan

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]
Quoted 3 lines
Cc [email protected]
Fixes 8dea75e11380 ("usb: typec: tcpm: Protocol Error handling")
Signed-off-by Badhri Jagan Sridharan <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
Quoted 27 lines
---
 drivers/usb/typec/tcpm/tcpm.c | 7 +++++++
 1 file changed, 7 insertions(+)
drivers/usb/typec/tcpm/tcpm.c +7 -0
index 5639b9a1e0bf..280ce1bd7b53 100644
@@ -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

Signature · 1 line
2.42.0.rc1.204.g551eb34607-goog