FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.6-stable tree

stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed

* FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.6-stable tree
@ 2026-05-28 13:39 gregkh
  2026-06-01 20:28 ` [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
  2026-06-02  2:06 ` Sasha Levin
  0 siblings, 2 replies; 4+ messages in thread
From: gregkh @ 2026-05-28 13:39 UTC (permalink / raw)
  To: abdurrahman, bartosz.golaszewski, linux; +Cc: stable

The patch below does not apply to the 6.6-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-6.6.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 '2026052831-abreast-slurp-dabc@gregkh' --subject-prefix 'PATCH 6.6.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] 4+ messages in thread

* [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock
  2026-05-28 13:39 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.6-stable tree gregkh
@ 2026-06-01 20:28 ` Sasha Levin
  2026-06-02  2:06 ` Sasha Levin
  1 sibling, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2026-06-01 20:28 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>
[ open-coded each `guard(pmbus_lock)(data->client)` as explicit `pmbus_lock_interruptible()`/`pmbus_unlock()` ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/pmbus/adm1266.c | 40 +++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index a8690d6c9b9cb0..518eaf07a123de 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -173,7 +173,12 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	ret = pmbus_lock_interruptible(data->client);
+	if (ret)
+		return ret;
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
+	pmbus_unlock(data->client);
 	if (ret < 0)
 		return ret;
 	if (ret < 2)
@@ -195,11 +200,19 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	ret = pmbus_lock_interruptible(data->client);
+	if (ret)
+		return ret;
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
-	if (ret < 0)
+	if (ret < 0) {
+		pmbus_unlock(data->client);
 		return ret;
-	if (ret < 2)
+	}
+	if (ret < 2) {
+		pmbus_unlock(data->client);
 		return -EIO;
+	}
 
 	status = read_buf[0] + (read_buf[1] << 8);
 
@@ -210,10 +223,14 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	}
 
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_PDIO_STATUS, read_buf);
-	if (ret < 0)
+	if (ret < 0) {
+		pmbus_unlock(data->client);
 		return ret;
-	if (ret < 2)
+	}
+	if (ret < 2) {
+		pmbus_unlock(data->client);
 		return -EIO;
+	}
 
 	status = read_buf[0] + (read_buf[1] << 8);
 
@@ -222,6 +239,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 			set_bit(gpio_nr, bits);
 	}
 
+	pmbus_unlock(data->client);
+
 	return 0;
 }
 
@@ -236,11 +255,16 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	if (pmbus_lock_interruptible(data->client))
+		return;
+
 	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);
-		if (ret != 2)
+		if (ret != 2) {
+			pmbus_unlock(data->client);
 			return;
+		}
 
 		gpio_config = read_buf[0];
 		seq_puts(s, adm1266_names[i]);
@@ -262,8 +286,10 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 	write_cmd = 0xFF;
 	ret = adm1266_pmbus_block_xfer(data, ADM1266_PDIO_CONFIG, 1, &write_cmd, read_buf);
-	if (ret != 32)
+	if (ret != 32) {
+		pmbus_unlock(data->client);
 		return;
+	}
 
 	for (i = 0; i < ADM1266_PDIO_NR; i++) {
 		seq_puts(s, adm1266_names[ADM1266_GPIO_NR + i]);
@@ -286,6 +312,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 		seq_puts(s, ")\n");
 	}
+
+	pmbus_unlock(data->client);
 }
 
 static int adm1266_config_gpio(struct adm1266_data *data)
-- 
2.53.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock
  2026-05-28 13:39 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.6-stable tree gregkh
  2026-06-01 20:28 ` [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
@ 2026-06-02  2:06 ` Sasha Levin
  2026-06-04  0:05   ` Sasha Levin
  1 sibling, 1 reply; 4+ messages in thread
From: Sasha Levin @ 2026-06-02  2:06 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>
[ open-coded `guard(pmbus_lock)()` as explicit `pmbus_lock_interruptible()`/`pmbus_unlock()` ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/pmbus/adm1266.c | 40 +++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index a8690d6c9b9cb0..518eaf07a123de 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -173,7 +173,12 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	ret = pmbus_lock_interruptible(data->client);
+	if (ret)
+		return ret;
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
+	pmbus_unlock(data->client);
 	if (ret < 0)
 		return ret;
 	if (ret < 2)
@@ -195,11 +200,19 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	ret = pmbus_lock_interruptible(data->client);
+	if (ret)
+		return ret;
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
-	if (ret < 0)
+	if (ret < 0) {
+		pmbus_unlock(data->client);
 		return ret;
-	if (ret < 2)
+	}
+	if (ret < 2) {
+		pmbus_unlock(data->client);
 		return -EIO;
+	}
 
 	status = read_buf[0] + (read_buf[1] << 8);
 
@@ -210,10 +223,14 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	}
 
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_PDIO_STATUS, read_buf);
-	if (ret < 0)
+	if (ret < 0) {
+		pmbus_unlock(data->client);
 		return ret;
-	if (ret < 2)
+	}
+	if (ret < 2) {
+		pmbus_unlock(data->client);
 		return -EIO;
+	}
 
 	status = read_buf[0] + (read_buf[1] << 8);
 
@@ -222,6 +239,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 			set_bit(gpio_nr, bits);
 	}
 
+	pmbus_unlock(data->client);
+
 	return 0;
 }
 
@@ -236,11 +255,16 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	if (pmbus_lock_interruptible(data->client))
+		return;
+
 	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);
-		if (ret != 2)
+		if (ret != 2) {
+			pmbus_unlock(data->client);
 			return;
+		}
 
 		gpio_config = read_buf[0];
 		seq_puts(s, adm1266_names[i]);
@@ -262,8 +286,10 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 	write_cmd = 0xFF;
 	ret = adm1266_pmbus_block_xfer(data, ADM1266_PDIO_CONFIG, 1, &write_cmd, read_buf);
-	if (ret != 32)
+	if (ret != 32) {
+		pmbus_unlock(data->client);
 		return;
+	}
 
 	for (i = 0; i < ADM1266_PDIO_NR; i++) {
 		seq_puts(s, adm1266_names[ADM1266_GPIO_NR + i]);
@@ -286,6 +312,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 		seq_puts(s, ")\n");
 	}
+
+	pmbus_unlock(data->client);
 }
 
 static int adm1266_config_gpio(struct adm1266_data *data)
-- 
2.53.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock
  2026-06-02  2:06 ` Sasha Levin
@ 2026-06-04  0:05   ` Sasha Levin
  0 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2026-06-04  0:05 UTC (permalink / raw)
  To: stable; +Cc: Sasha Levin, Abdurrahman Hussain, Bartosz Golaszewski,
	Guenter Roeck

> [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with
> pmbus_lock
> [ open-coded each guard(pmbus_lock)(data->client) as explicit
>   pmbus_lock_interruptible()/pmbus_unlock() ]

Queued for 6.6.y and 6.1.y, thanks.

-- 
Thanks,
Sasha

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2026-06-04  0:05 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-28 13:39 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 6.6-stable tree gregkh
2026-06-01 20:28 ` [PATCH 6.6.y] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
2026-06-02  2:06 ` Sasha Levin
2026-06-04  0:05   ` Sasha Levin

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).