* FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.18-stable tree
@ 2026-05-28 13:50 gregkh
2026-06-01 13:53 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 14:01 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
0 siblings, 2 replies; 8+ messages in thread
From: gregkh @ 2026-05-28 13:50 UTC (permalink / raw)
To: abdurrahman, bartosz.golaszewski, linux; +Cc: stable
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 <stable@vger.kernel.org>.
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 '<stable@vger.kernel.org>' --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 <abdurrahman@nexthop.ai>
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: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-6-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 3e8f2619cb9b..0eef58dd69a6 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -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);
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock
2026-05-28 13:51 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read" failed to apply to 6.18-stable tree gregkh
@ 2026-06-01 12:49 ` Sasha Levin
0 siblings, 0 replies; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 12:49 UTC (permalink / raw)
To: stable; +Cc: Guenter Roeck, Sanman Pradhan, Sasha Levin
From: Guenter Roeck <linux@roeck-us.net>
[ 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 <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: 4e4af55aaca7 ("hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus.h | 5 +++++
drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -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);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock
2026-05-28 13:48 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with" failed to apply to 6.18-stable tree gregkh
@ 2026-06-01 13:51 ` Sasha Levin
2026-06-01 14:46 ` Sasha Levin
1 sibling, 0 replies; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 13:51 UTC (permalink / raw)
To: stable; +Cc: Guenter Roeck, Sanman Pradhan, Sasha Levin
From: Guenter Roeck <linux@roeck-us.net>
[ 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 <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: 9f1dd8f9491e ("hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus.h | 5 +++++
drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -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);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock
2026-05-28 13:50 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.18-stable tree gregkh
@ 2026-06-01 13:53 ` Sasha Levin
2026-06-01 13:53 ` [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
2026-06-01 14:01 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
1 sibling, 1 reply; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 13:53 UTC (permalink / raw)
To: stable; +Cc: Guenter Roeck, Sanman Pradhan, Sasha Levin
From: Guenter Roeck <linux@roeck-us.net>
[ 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 <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: bab8c6fb5af8 ("hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus.h | 5 +++++
drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -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);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock
2026-06-01 13:53 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
@ 2026-06-01 13:53 ` Sasha Levin
0 siblings, 0 replies; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 13:53 UTC (permalink / raw)
To: stable; +Cc: Abdurrahman Hussain, Bartosz Golaszewski, Guenter Roeck,
Sasha Levin
From: Abdurrahman Hussain <abdurrahman@nexthop.ai>
[ Upstream commit bab8c6fb5af8df7e753d196c1262cb78e92ca872 ]
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: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-6-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/adm1266.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index d90f8f80be8e0..e077944ebd6f5 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock
2026-05-28 13:50 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.18-stable tree gregkh
2026-06-01 13:53 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
@ 2026-06-01 14:01 ` Sasha Levin
2026-06-01 14:01 ` [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
1 sibling, 1 reply; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 14:01 UTC (permalink / raw)
To: stable; +Cc: Guenter Roeck, Sanman Pradhan, Sasha Levin
From: Guenter Roeck <linux@roeck-us.net>
[ 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 <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: bab8c6fb5af8 ("hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus.h | 5 +++++
drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -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);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock
2026-06-01 14:01 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
@ 2026-06-01 14:01 ` Sasha Levin
0 siblings, 0 replies; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 14:01 UTC (permalink / raw)
To: stable; +Cc: Abdurrahman Hussain, Bartosz Golaszewski, Guenter Roeck,
Sasha Levin
From: Abdurrahman Hussain <abdurrahman@nexthop.ai>
[ Upstream commit bab8c6fb5af8df7e753d196c1262cb78e92ca872 ]
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: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-6-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/adm1266.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index d90f8f80be8e0..e077944ebd6f5 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock
2026-05-28 13:48 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with" failed to apply to 6.18-stable tree gregkh
2026-06-01 13:51 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
@ 2026-06-01 14:46 ` Sasha Levin
1 sibling, 0 replies; 8+ messages in thread
From: Sasha Levin @ 2026-06-01 14:46 UTC (permalink / raw)
To: stable; +Cc: Guenter Roeck, Sanman Pradhan, Sasha Levin
From: Guenter Roeck <linux@roeck-us.net>
[ 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 <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: 9f1dd8f9491e ("hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus.h | 5 +++++
drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -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);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -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);
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-06-01 14:46 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2026-05-28 13:50 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.18-stable tree gregkh
2026-06-01 13:53 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 13:53 ` [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
2026-06-01 14:01 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 14:01 ` [PATCH 6.18.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
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2026-05-28 13:51 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read" failed to apply to 6.18-stable tree gregkh
2026-06-01 12:49 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-05-28 13:48 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with" failed to apply to 6.18-stable tree gregkh
2026-06-01 13:51 ` [PATCH 6.18.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 14:46 ` Sasha Levin
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