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Fix some VDM AMS handling

PATCH In review Kyle Tso 2 participants 5 messages May 23, 2021 – May 24, 2021

Subsystems (3)
USB USB Type-C class USB Type-C port controller drivers
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Kyle Tso

author
#0 lore raw

v2 cover Fix some VDM AMS handling

Changes since v1:
-----------------
usb: typec: tcpm: Properly interrupt VDM AMS
- fix the bug reported by "kernel test robot <[email protected]>"
- add Reviewed-by: tag from Guenter

usb: typec: tcpm: Respond Not_Supported if no snk_vdo
- no changes in code
- add Reviewed-by: tag from Guenter

v1 cover letter:
----------------
usb: typec: tcpm: Properly interrupt VDM AMS
- If VDM AMS is interrupted by Messages other than VDM, the current VDM AMS should be finished before handling the just arrived request. I add intercept code in the beginning of the handler of the three types of requests (control/data/extended) to ensure that the AMS is finished first.

usb: typec: tcpm: Respond Not_Supported if no snk_vdo
- The snk_vdo is for the responses to incoming VDM Discover Identity. If there is no data in snk_vdo, it means that the port doesn't even support it. According to PD3 Spec "Table 6-64 Response to an incoming VDM", the port should send Not_Supported Message as the response. For PD2 cases, it is defined in PD2 Spec "Table 6-41 Applicability of Structured VDM Commands - Note 3" that the port should "Ignore" the command.

Kyle Tso (2):
usb: typec: tcpm: Properly interrupt VDM AMS
usb: typec: tcpm: Respond Not_Supported if no snk_vdo

 drivers/usb/typec/tcpm/tcpm.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)
Signature · 1 line
2.31.1.818.g46aad6cb9e-goog
author
#1 lore raw

PATCH v2 1/2 usb: typec: tcpm: Properly interrupt VDM AMS

When a VDM AMS is interrupted by Messages other than VDM, the AMS needs to be finished properly. Also start a VDM AMS if receiving SVDM Commands from the port partner to complement the functionality of tcpm_vdm_ams().

Fixes 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance")
Signed-off-by Kyle Tso <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
---
 drivers/usb/typec/tcpm/tcpm.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
drivers/usb/typec/tcpm/tcpm.c +30 -0
index 3feaf5d6419e..7db6ae3e9c0b 100644
@@ -1578,6 +1578,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
 				typec_partner_set_svdm_version(port->partner,
 							       PD_VDO_SVDM_VER(p[0]));
+
+			tcpm_ams_start(port, DISCOVER_IDENTITY);
 			/* 6.4.4.3.1: Only respond as UFP (device) */
 			if (port->data_role == TYPEC_DEVICE &&
 			    port->nr_snk_vdo) {

@@ -1596,14 +1598,19 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			}
 			break;
 		case CMD_DISCOVER_SVID:
+			tcpm_ams_start(port, DISCOVER_SVIDS);
 			break;
 		case CMD_DISCOVER_MODES:
+			tcpm_ams_start(port, DISCOVER_MODES);
 			break;
 		case CMD_ENTER_MODE:
+			tcpm_ams_start(port, DFP_TO_UFP_ENTER_MODE);
 			break;
 		case CMD_EXIT_MODE:
+			tcpm_ams_start(port, DFP_TO_UFP_EXIT_MODE);
 			break;
 		case CMD_ATTENTION:
+			tcpm_ams_start(port, ATTENTION);
 			/* Attention command does not have response */
 			*adev_action = ADEV_ATTENTION;
 			return 0;

@@ -2315,6 +2322,12 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 	bool frs_enable;
 	int ret;
 
+	if (tcpm_vdm_ams(port) && type != PD_DATA_VENDOR_DEF) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	switch (type) {
 	case PD_DATA_SOURCE_CAP:
 		for (i = 0; i < cnt; i++)

@@ -2487,6 +2500,16 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 	enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
 	enum tcpm_state next_state;
 
+	/*
+	 * Stop VDM state machine if interrupted by other Messages while NOT_SUPP is allowed in
+	 * VDM AMS if waiting for VDM responses and will be handled later.
+	 */
+	if (tcpm_vdm_ams(port) && type != PD_CTRL_NOT_SUPP && type != PD_CTRL_GOOD_CRC) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	switch (type) {
 	case PD_CTRL_GOOD_CRC:
 	case PD_CTRL_PING:

@@ -2745,6 +2768,13 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 	enum pd_ext_msg_type type = pd_header_type_le(msg->header);
 	unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);
 
+	/* stopping VDM state machine if interrupted by other Messages */
+	if (tcpm_vdm_ams(port)) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	if (!(msg->ext_msg.header & PD_EXT_HDR_CHUNKED)) {
 		tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		tcpm_log(port, "Unchunked extended messages unsupported");
Signature · 1 line
2.31.1.818.g46aad6cb9e-goog
maintainer Acked-by on v2 1/2
#2 lore raw

Re: [PATCH v2 1/2] usb: typec: tcpm: Properly interrupt VDM AMS

Quoted 7 lines · Kyle Tso

When a VDM AMS is interrupted by Messages other than VDM, the AMS needs to be finished properly. Also start a VDM AMS if receiving SVDM Commands from the port partner to complement the functionality of tcpm_vdm_ams().

Fixes 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance")
Signed-off-by Kyle Tso <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
Acked-by Heikki Krogerus <[email protected]>
Quoted 83 lines
---
 drivers/usb/typec/tcpm/tcpm.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
drivers/usb/typec/tcpm/tcpm.c +30 -0
index 3feaf5d6419e..7db6ae3e9c0b 100644
@@ -1578,6 +1578,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
 				typec_partner_set_svdm_version(port->partner,
 							       PD_VDO_SVDM_VER(p[0]));
+
+			tcpm_ams_start(port, DISCOVER_IDENTITY);
 			/* 6.4.4.3.1: Only respond as UFP (device) */
 			if (port->data_role == TYPEC_DEVICE &&
 			    port->nr_snk_vdo) {

@@ -1596,14 +1598,19 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			}
 			break;
 		case CMD_DISCOVER_SVID:
+			tcpm_ams_start(port, DISCOVER_SVIDS);
 			break;
 		case CMD_DISCOVER_MODES:
+			tcpm_ams_start(port, DISCOVER_MODES);
 			break;
 		case CMD_ENTER_MODE:
+			tcpm_ams_start(port, DFP_TO_UFP_ENTER_MODE);
 			break;
 		case CMD_EXIT_MODE:
+			tcpm_ams_start(port, DFP_TO_UFP_EXIT_MODE);
 			break;
 		case CMD_ATTENTION:
+			tcpm_ams_start(port, ATTENTION);
 			/* Attention command does not have response */
 			*adev_action = ADEV_ATTENTION;
 			return 0;

@@ -2315,6 +2322,12 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 	bool frs_enable;
 	int ret;
 
+	if (tcpm_vdm_ams(port) && type != PD_DATA_VENDOR_DEF) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	switch (type) {
 	case PD_DATA_SOURCE_CAP:
 		for (i = 0; i < cnt; i++)

@@ -2487,6 +2500,16 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 	enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
 	enum tcpm_state next_state;
 
+	/*
+	 * Stop VDM state machine if interrupted by other Messages while NOT_SUPP is allowed in
+	 * VDM AMS if waiting for VDM responses and will be handled later.
+	 */
+	if (tcpm_vdm_ams(port) && type != PD_CTRL_NOT_SUPP && type != PD_CTRL_GOOD_CRC) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	switch (type) {
 	case PD_CTRL_GOOD_CRC:
 	case PD_CTRL_PING:

@@ -2745,6 +2768,13 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 	enum pd_ext_msg_type type = pd_header_type_le(msg->header);
 	unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);
 
+	/* stopping VDM state machine if interrupted by other Messages */
+	if (tcpm_vdm_ams(port)) {
+		port->vdm_state = VDM_STATE_ERR_BUSY;
+		tcpm_ams_finish(port);
+		mod_vdm_delayed_work(port, 0);
+	}
+
 	if (!(msg->ext_msg.header & PD_EXT_HDR_CHUNKED)) {
 		tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		tcpm_log(port, "Unchunked extended messages unsupported");
Signature · 1 line
2.31.1.818.g46aad6cb9e-goog
Signature · 1 line
heikki
author
#3 lore raw

PATCH v2 2/2 usb: typec: tcpm: Respond Not_Supported if no snk_vdo

In reply to Kyle Tso

If snk_vdo is not populated from fwnode, it implies the port does not support responding to SVDM commands. Not_Supported Message shall be sent if the contract is in PD3. And for PD2, the port shall ignore the commands.

Fixes 193a68011fdc ("staging: typec: tcpm: Respond to Discover Identity commands")
Signed-off-by Kyle Tso <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
---
 drivers/usb/typec/tcpm/tcpm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/usb/typec/tcpm/tcpm.c +4 -1
index 7db6ae3e9c0b..a56bc71f4eb5 100644
@@ -2458,7 +2458,10 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 					   NONE_AMS);
 		break;
 	case PD_DATA_VENDOR_DEF:
-		tcpm_handle_vdm_request(port, msg->payload, cnt);
+		if (tcpm_vdm_ams(port) || port->nr_snk_vdo)
+			tcpm_handle_vdm_request(port, msg->payload, cnt);
+		else if (port->negotiated_rev > PD_REV20)
+			tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		break;
 	case PD_DATA_BIST:
 		port->bist_request = le32_to_cpu(msg->payload[0]);
Signature · 1 line
2.31.1.818.g46aad6cb9e-goog
maintainer Acked-by on v2 2/2
#4 lore raw

Re: [PATCH v2 2/2] usb: typec: tcpm: Respond Not_Supported if no snk_vdo

Quoted 8 lines · Kyle Tso

If snk_vdo is not populated from fwnode, it implies the port does not support responding to SVDM commands. Not_Supported Message shall be sent if the contract is in PD3. And for PD2, the port shall ignore the commands.

Fixes 193a68011fdc ("staging: typec: tcpm: Respond to Discover Identity commands")
Signed-off-by Kyle Tso <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
Acked-by Heikki Krogerus <[email protected]>
Quoted 22 lines
---
 drivers/usb/typec/tcpm/tcpm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/usb/typec/tcpm/tcpm.c +4 -1
index 7db6ae3e9c0b..a56bc71f4eb5 100644
@@ -2458,7 +2458,10 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 					   NONE_AMS);
 		break;
 	case PD_DATA_VENDOR_DEF:
-		tcpm_handle_vdm_request(port, msg->payload, cnt);
+		if (tcpm_vdm_ams(port) || port->nr_snk_vdo)
+			tcpm_handle_vdm_request(port, msg->payload, cnt);
+		else if (port->negotiated_rev > PD_REV20)
+			tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		break;
 	case PD_DATA_BIST:
 		port->bist_request = le32_to_cpu(msg->payload[0]);
Signature · 1 line
2.31.1.818.g46aad6cb9e-goog
Signature · 1 line
heikki