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usb: typec: tcpci: clear the fault status bit

PATCH In review Fabio Estevam 4 participants 4 messages Aug 16, 2023 – Aug 22, 2023

Subsystems (4)
Stable branch USB USB Type-C class USB Type-C port controller drivers
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Fabio Estevam

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#0 lore raw

PATCH v3 1/1 usb: typec: tcpci: clear the fault status bit

From: Marco Felsch <[email protected]>

According the "USB Type-C Port Controller Interface Specification v2.0" the TCPC sets the fault status register bit-7 (AllRegistersResetToDefault) once the registers have been reset to their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the fault-irq, which may cause a kernel hang. Fix this generically by writing a one to the corresponding bit-7.

Cc [email protected]
Fixes 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by Angus Ainslie (Purism) <[email protected]>
Closes https://lore.kernel.org/all/[email protected]/ open here
Reported-by Christian Bach <[email protected]>
Closes https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/ open here
Signed-off-by Marco Felsch <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>

---
Changes since v2:
- Submitted it as a standalone patch.
- Explain that it may cause a kernel hang.
- Fixed typos in the commit log. (Guenter)
- Check the tcpci_write16() return value. (Guenter)
- Write to TCPC_FAULT_STATUS unconditionally. (Guenter)
- Added Fixes, Reported-by and Closes tags.
- CCed stable

 drivers/usb/typec/tcpm/tcpci.c | 4 ++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 5 insertions(+)
drivers/usb/typec/tcpm/tcpci.c +4 -0
index fc708c289a73..0ee3e6e29bb1 100644
@@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+	if (ret < 0)
+		return ret;
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
include/linux/usb/tcpci.h +1 -0
index 85e95a3251d3..83376473ac76 100644
@@ -103,6 +103,7 @@
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21
Signature · 1 line
2.34.1
Reviewed-by on v3 1/1
#1 lore raw
Quoted 11 lines · Fabio Estevam

From: Marco Felsch <[email protected]>

According the "USB Type-C Port Controller Interface Specification v2.0" the TCPC sets the fault status register bit-7 (AllRegistersResetToDefault) once the registers have been reset to their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the fault-irq, which may cause a kernel hang. Fix this generically by writing a one to the corresponding bit-7.

Quoted 8 lines
Cc [email protected]
Fixes 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by Angus Ainslie (Purism) <[email protected]>
Closes https://lore.kernel.org/all/[email protected]/ open here
Reported-by Christian Bach <[email protected]>
Closes https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/ open here
Signed-off-by Marco Felsch <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>
Reviewed-by Guenter Roeck <[email protected]>
Quoted 44 lines

---
Changes since v2:
- Submitted it as a standalone patch.
- Explain that it may cause a kernel hang.
- Fixed typos in the commit log. (Guenter)
- Check the tcpci_write16() return value. (Guenter)
- Write to TCPC_FAULT_STATUS unconditionally. (Guenter)
- Added Fixes, Reported-by and Closes tags.
- CCed stable

 drivers/usb/typec/tcpm/tcpci.c | 4 ++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 5 insertions(+)
drivers/usb/typec/tcpm/tcpci.c +4 -0
index fc708c289a73..0ee3e6e29bb1 100644
@@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+	if (ret < 0)
+		return ret;
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
include/linux/usb/tcpci.h +1 -0
index 85e95a3251d3..83376473ac76 100644
@@ -103,6 +103,7 @@
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21
Signature · 1 line
2.34.1
#2 lore raw
In reply to Fabio Estevam
Quoted 19 lines · Fabio Estevam

From: Marco Felsch <[email protected]>

According the "USB Type-C Port Controller Interface Specification v2.0" the TCPC sets the fault status register bit-7 (AllRegistersResetToDefault) once the registers have been reset to their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the fault-irq, which may cause a kernel hang. Fix this generically by writing a one to the corresponding bit-7.

Cc [email protected]
Fixes 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by Angus Ainslie (Purism) <[email protected]>
Closes https://lore.kernel.org/all/[email protected]/ open here
Reported-by Christian Bach <[email protected]>
Closes https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/ open here
Signed-off-by Marco Felsch <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>
Quoted 9 lines

---
Changes since v2:
- Submitted it as a standalone patch.
- Explain that it may cause a kernel hang.
- Fixed typos in the commit log. (Guenter)
- Check the tcpci_write16() return value. (Guenter)
- Write to TCPC_FAULT_STATUS unconditionally. (Guenter)
- Added Fixes, Reported-by and Closes tags.
- CCed stable

thanks for the work Fabio :)

Regards,
Marco

Quoted 36 lines
 drivers/usb/typec/tcpm/tcpci.c | 4 ++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 5 insertions(+)
drivers/usb/typec/tcpm/tcpci.c +4 -0
index fc708c289a73..0ee3e6e29bb1 100644
@@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+	if (ret < 0)
+		return ret;
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
include/linux/usb/tcpci.h +1 -0
index 85e95a3251d3..83376473ac76 100644
@@ -103,6 +103,7 @@
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21
Signature · 1 line
2.34.1
maintainer Reviewed-by on v3 1/1
#3 lore raw
In reply to Fabio Estevam
Quoted 11 lines · Fabio Estevam

From: Marco Felsch <[email protected]>

According the "USB Type-C Port Controller Interface Specification v2.0" the TCPC sets the fault status register bit-7 (AllRegistersResetToDefault) once the registers have been reset to their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the fault-irq, which may cause a kernel hang. Fix this generically by writing a one to the corresponding bit-7.

Quoted 8 lines
Cc [email protected]
Fixes 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by Angus Ainslie (Purism) <[email protected]>
Closes https://lore.kernel.org/all/[email protected]/ open here
Reported-by Christian Bach <[email protected]>
Closes https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/ open here
Signed-off-by Marco Felsch <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>
Reviewed-by Heikki Krogerus <[email protected]>
Quoted 43 lines

---
Changes since v2:
- Submitted it as a standalone patch.
- Explain that it may cause a kernel hang.
- Fixed typos in the commit log. (Guenter)
- Check the tcpci_write16() return value. (Guenter)
- Write to TCPC_FAULT_STATUS unconditionally. (Guenter)
- Added Fixes, Reported-by and Closes tags.
- CCed stable

 drivers/usb/typec/tcpm/tcpci.c | 4 ++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 5 insertions(+)
drivers/usb/typec/tcpm/tcpci.c +4 -0
index fc708c289a73..0ee3e6e29bb1 100644
@@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+	if (ret < 0)
+		return ret;
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
include/linux/usb/tcpci.h +1 -0
index 85e95a3251d3..83376473ac76 100644
@@ -103,6 +103,7 @@
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21
Signature · 1 line
2.34.1
Signature · 1 line
heikki