FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.18-stable tree

PATCH New [email protected] 2 participants 5 messages May 28 – Jun 1

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[email protected]

author maintainer

2026-05-28 13:51 UTC #0 lore raw

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x bab8c6fb5af8df7e753d196c1262cb78e92ca872
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026052841-exquisite-attach-1b4c@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bab8c6fb5af8df7e753d196c1262cb78e92ca872 Mon Sep 17 00:00:00 2001
From: Abdurrahman Hussain <[email protected]>
Date: Mon, 18 May 2026 17:52:30 -0700
Subject: [PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with
pmbus_lock

adm1266_gpio_get(), adm1266_gpio_get_multiple(), and adm1266_gpio_dbg_show() all issue PMBus reads against the device but none of them take pmbus_lock. The pmbus_core framework holds pmbus_lock around its own multi-transaction sequences (notably the "set PAGE, then read paged register" pattern used by hwmon attributes), so an unlocked GPIO accessor can land between a PAGE write and the subsequent paged read in another thread and corrupt either side's view of the device state machine.

Take pmbus_lock at the top of each of the three accessors via the scope-based guard(). The lock is uncontended in the common case and adds only a single mutex round-trip per call.

Fixes d98dfad35c38 ("hwmon: (pmbus/adm1266) Add support for GPIOs")

Cc [email protected]

Signed-off-by Abdurrahman Hussain <[email protected]>

Reviewed-by Bartosz Golaszewski <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Guenter Roeck <[email protected]>

drivers/hwmon/pmbus/adm1266.c +6 -0

index 3e8f2619cb9b..0eef58dd69a6 100644
@@ -173,6 +173,8 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
 	if (ret < 0)
 		return ret;

@@ -195,6 +197,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
 	if (ret < 0)
 		return ret;

@@ -236,6 +240,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	guard(pmbus_lock)(data->client);
+
 	for (i = 0; i < ADM1266_GPIO_NR; i++) {
 		write_cmd = adm1266_gpio_mapping[i][1];
 		ret = adm1266_pmbus_block_xfer(data, ADM1266_GPIO_CONFIG, 1, &write_cmd, read_buf);

Sasha Levin

maintainer

2026-06-01 13:53 UTC #1 lore raw

PATCH 1/2 hwmon: (pmbus) Add support for guarded PMBus lock

From: Guenter Roeck <[email protected]>

[ Upstream commit 1814f4d3ff358277a5b6957e7f133c2812dc80ec ]

Add support for guard(pmbus_lock)() and scoped_guard(pmbus_lock)() to be able to simplify the PMBus code.

Also introduce pmbus_lock() as pre-requisite for supporting guard().

Reviewed-by Sanman Pradhan <[email protected]>

Signed-off-by Guenter Roeck <[email protected]>

Stable-dep-of: bab8c6fb5af8 ("hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock")

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/hwmon/pmbus/pmbus.h      | 5 +++++
 drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
 2 files changed, 13 insertions(+)

drivers/hwmon/pmbus/pmbus.h +5 -0

index d2e9bfb5320fc..e499cdae9442c 100644
@@ -10,6 +10,7 @@
 #define PMBUS_H
 
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/regulator/driver.h>
 
 /*

@@ -563,7 +564,11 @@ int pmbus_get_fan_rate_device(struct i2c_client *client, int page, int id,
 int pmbus_get_fan_rate_cached(struct i2c_client *client, int page, int id,
 			      enum pmbus_fan_mode mode);
 int pmbus_lock_interruptible(struct i2c_client *client);
+void pmbus_lock(struct i2c_client *client);
 void pmbus_unlock(struct i2c_client *client);
+
+DEFINE_GUARD(pmbus_lock, struct i2c_client *, pmbus_lock(_T), pmbus_unlock(_T))
+
 int pmbus_update_fan(struct i2c_client *client, int page, int id,
 		     u8 config, u8 mask, u16 command);
 struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client);

drivers/hwmon/pmbus/pmbus_core.c +8 -0

index 572be3ebc03df..7150f12d26300 100644
@@ -3871,6 +3871,14 @@ struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client)
 }
 EXPORT_SYMBOL_NS_GPL(pmbus_get_debugfs_dir, "PMBUS");
 
+void pmbus_lock(struct i2c_client *client)
+{
+	struct pmbus_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+}
+EXPORT_SYMBOL_NS_GPL(pmbus_lock, "PMBUS");
+
 int pmbus_lock_interruptible(struct i2c_client *client)
 {
 	struct pmbus_data *data = i2c_get_clientdata(client);

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-06-01 13:53 UTC #2 lore raw

PATCH 2/2 hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock

From: Abdurrahman Hussain <[email protected]>

[ Upstream commit bab8c6fb5af8df7e753d196c1262cb78e92ca872 ]

Take pmbus_lock at the top of each of the three accessors via the scope-based guard(). The lock is uncontended in the common case and adds only a single mutex round-trip per call.

Fixes d98dfad35c38 ("hwmon: (pmbus/adm1266) Add support for GPIOs")

Cc [email protected]

Signed-off-by Abdurrahman Hussain <[email protected]>

Reviewed-by Bartosz Golaszewski <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Guenter Roeck <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/hwmon/pmbus/adm1266.c | 6 ++++++
 1 file changed, 6 insertions(+)

drivers/hwmon/pmbus/adm1266.c +6 -0

index d90f8f80be8e0..e077944ebd6f5 100644
@@ -172,6 +172,8 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
 	if (ret < 0)
 		return ret;

@@ -192,6 +194,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
 	if (ret < 0)
 		return ret;

@@ -230,6 +234,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	guard(pmbus_lock)(data->client);
+
 	for (i = 0; i < ADM1266_GPIO_NR; i++) {
 		write_cmd = adm1266_gpio_mapping[i][1];
 		ret = adm1266_pmbus_block_xfer(data, ADM1266_GPIO_CONFIG, 1, &write_cmd, read_buf);

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-06-01 14:01 UTC #3 lore raw

PATCH 1/2 hwmon: (pmbus) Add support for guarded PMBus lock

In reply to [email protected]

From: Guenter Roeck <[email protected]>

[ Upstream commit 1814f4d3ff358277a5b6957e7f133c2812dc80ec ]

Add support for guard(pmbus_lock)() and scoped_guard(pmbus_lock)() to be able to simplify the PMBus code.

Also introduce pmbus_lock() as pre-requisite for supporting guard().

Reviewed-by Sanman Pradhan <[email protected]>

Signed-off-by Guenter Roeck <[email protected]>

Stable-dep-of: bab8c6fb5af8 ("hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock")

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/hwmon/pmbus/pmbus.h      | 5 +++++
 drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
 2 files changed, 13 insertions(+)

drivers/hwmon/pmbus/pmbus.h +5 -0

index d2e9bfb5320fc..e499cdae9442c 100644
@@ -10,6 +10,7 @@
 #define PMBUS_H
 
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/regulator/driver.h>
 
 /*

@@ -563,7 +564,11 @@ int pmbus_get_fan_rate_device(struct i2c_client *client, int page, int id,
 int pmbus_get_fan_rate_cached(struct i2c_client *client, int page, int id,
 			      enum pmbus_fan_mode mode);
 int pmbus_lock_interruptible(struct i2c_client *client);
+void pmbus_lock(struct i2c_client *client);
 void pmbus_unlock(struct i2c_client *client);
+
+DEFINE_GUARD(pmbus_lock, struct i2c_client *, pmbus_lock(_T), pmbus_unlock(_T))
+
 int pmbus_update_fan(struct i2c_client *client, int page, int id,
 		     u8 config, u8 mask, u16 command);
 struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client);

drivers/hwmon/pmbus/pmbus_core.c +8 -0

index 572be3ebc03df..7150f12d26300 100644
@@ -3871,6 +3871,14 @@ struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client)
 }
 EXPORT_SYMBOL_NS_GPL(pmbus_get_debugfs_dir, "PMBUS");
 
+void pmbus_lock(struct i2c_client *client)
+{
+	struct pmbus_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+}
+EXPORT_SYMBOL_NS_GPL(pmbus_lock, "PMBUS");
+
 int pmbus_lock_interruptible(struct i2c_client *client)
 {
 	struct pmbus_data *data = i2c_get_clientdata(client);

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-06-01 14:01 UTC #4 lore raw

PATCH 2/2 hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock

From: Abdurrahman Hussain <[email protected]>

[ Upstream commit bab8c6fb5af8df7e753d196c1262cb78e92ca872 ]

Take pmbus_lock at the top of each of the three accessors via the scope-based guard(). The lock is uncontended in the common case and adds only a single mutex round-trip per call.

Fixes d98dfad35c38 ("hwmon: (pmbus/adm1266) Add support for GPIOs")

Cc [email protected]

Signed-off-by Abdurrahman Hussain <[email protected]>

Reviewed-by Bartosz Golaszewski <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Guenter Roeck <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/hwmon/pmbus/adm1266.c | 6 ++++++
 1 file changed, 6 insertions(+)

drivers/hwmon/pmbus/adm1266.c +6 -0

index d90f8f80be8e0..e077944ebd6f5 100644
@@ -172,6 +172,8 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
 	if (ret < 0)
 		return ret;

@@ -192,6 +194,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
 	if (ret < 0)
 		return ret;

@@ -230,6 +234,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	guard(pmbus_lock)(data->client);
+
 	for (i = 0; i < ADM1266_GPIO_NR; i++) {
 		write_cmd = adm1266_gpio_mapping[i][1];
 		ret = adm1266_pmbus_block_xfer(data, ADM1266_GPIO_CONFIG, 1, &write_cmd, read_buf);

Signature · 1 line

2.53.0