FAILED: patch "[PATCH] power: supply: max17040: drop incorrect I2C functionality" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] power: supply: max17040: drop incorrect I2C functionality" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 4e4b9f5ce9dfb8ed4b8d1262a504b8043ac09d87
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090305-skinhead-nursing-7dcb@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 4e4b9f5ce9dfb8ed4b8d1262a504b8043ac09d87 Mon Sep 17 00:00:00 2001
From: Jianing Li <m13940358460@163.com>
Date: Fri, 31 Jul 2026 16:42:59 +0800
Subject: [PATCH] power: supply: max17040: drop incorrect I2C functionality
 check

max17040_probe() rejects adapters that do not advertise
I2C_FUNC_SMBUS_BYTE. The driver does not issue SMBus byte transactions,
however. Its regmap has 8-bit registers and 16-bit big-endian values, for
which regmap-i2c supports either raw I2C transfers or SMBus word-data
transactions.

Consequently, an adapter providing raw I2C transfers or SMBus word data
but not SMBus byte transactions is rejected even though regmap can access
the device. Conversely, the current check can pass an adapter that regmap
cannot use.

Drop the stale check and let devm_regmap_init_i2c() validate and select
the supported transfer method.

Fixes: 6455a8a84bdfd ("power: supply: max17040: Use regmap i2c")
Cc: stable@vger.kernel.org
Signed-off-by: Jianing Li <m13940358460@163.com>
Link: https://patch.msgid.link/20260731084259.916-1-m13940358460@163.com
[Fixed Fixes tag, so that it points to the regmap introduction instead of the initial driver addition]
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 98d34d5f3c80..b641d7387311 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -470,16 +470,12 @@ static const struct power_supply_desc max17040_battery_desc = {
 static int max17040_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
-	struct i2c_adapter *adapter = client->adapter;
 	struct power_supply_config psy_cfg = {};
 	struct max17040_chip *chip;
 	enum chip_id chip_id;
 	bool enable_irq = false;
 	int ret;
 
-	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
-		return -EIO;
-
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;

[PATCH 6.1.y 1/3] i2c: core: Introduce i2c_client_get_device_id helper function

[Sasha Levin]

From: Angel Iglesias <ang.iglesiasg@gmail.com>

[ Upstream commit 662233731d66cf41e7494e532e702849c8ce18f3 ]

Introduces new helper function to aid in .probe_new() refactors. In order
to use existing i2c_get_device_id() on the probe callback, the device
match table needs to be accessible in that function, which would require
bigger refactors in some drivers using the deprecated .probe callback.

This issue was discussed in more detail in the IIO mailing list.

Link: https://lore.kernel.org/all/20221023132302.911644-11-u.kleine-koenig@pengutronix.de/
Suggested-by: Nuno Sá <noname.nuno@gmail.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 4e4b9f5ce9df ("power: supply: max17040: drop incorrect I2C functionality check")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 14 ++++++++++++++
 include/linux/i2c.h         |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index ade12c0b1006c..588424db22a22 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -2426,6 +2426,20 @@ int i2c_get_device_id(const struct i2c_client *client,
 }
 EXPORT_SYMBOL_GPL(i2c_get_device_id);
 
+/**
+ * i2c_client_get_device_id - get the driver match table entry of a device
+ * @client: the device to query. The device must be bound to a driver
+ *
+ * Returns a pointer to the matching entry if found, NULL otherwise.
+ */
+const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client)
+{
+	const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);
+
+	return i2c_match_id(drv->id_table, client);
+}
+EXPORT_SYMBOL_GPL(i2c_client_get_device_id);
+
 /* ----------------------------------------------------
  * the i2c address scanning function
  * Will not work for 10-bit addresses!
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 87b403a6d7e41..60c5bc674dcce 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -189,6 +189,7 @@ s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
 					      u8 *values);
 int i2c_get_device_id(const struct i2c_client *client,
 		      struct i2c_device_identity *id);
+const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client);
 #endif /* I2C */
 
 /**
-- 
2.53.0

[PATCH 6.1.y 2/3] power: supply: max17040: Convert to i2c's .probe_new()

[Sasha Levin]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ Upstream commit a07fca69378c26ea034826feb0011256e25ad237 ]

.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in the probe function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Stable-dep-of: 4e4b9f5ce9df ("power: supply: max17040: drop incorrect I2C functionality check")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/max17040_battery.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index a9aef1e8b186e..d1075959dd466 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -430,9 +430,9 @@ static const struct power_supply_desc max17040_battery_desc = {
 	.num_properties		= ARRAY_SIZE(max17040_battery_props),
 };
 
-static int max17040_probe(struct i2c_client *client,
-			const struct i2c_device_id *id)
+static int max17040_probe(struct i2c_client *client)
 {
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
 	struct i2c_adapter *adapter = client->adapter;
 	struct power_supply_config psy_cfg = {};
 	struct max17040_chip *chip;
@@ -599,7 +599,7 @@ static struct i2c_driver max17040_i2c_driver = {
 		.of_match_table = max17040_of_match,
 		.pm	= MAX17040_PM_OPS,
 	},
-	.probe		= max17040_probe,
+	.probe_new	= max17040_probe,
 	.id_table	= max17040_id,
 };
 module_i2c_driver(max17040_i2c_driver);
-- 
2.53.0

[PATCH 6.1.y 3/3] power: supply: max17040: drop incorrect I2C functionality check

[Sasha Levin]

From: Jianing Li <m13940358460@163.com>

[ Upstream commit 4e4b9f5ce9dfb8ed4b8d1262a504b8043ac09d87 ]

max17040_probe() rejects adapters that do not advertise
I2C_FUNC_SMBUS_BYTE. The driver does not issue SMBus byte transactions,
however. Its regmap has 8-bit registers and 16-bit big-endian values, for
which regmap-i2c supports either raw I2C transfers or SMBus word-data
transactions.

Consequently, an adapter providing raw I2C transfers or SMBus word data
but not SMBus byte transactions is rejected even though regmap can access
the device. Conversely, the current check can pass an adapter that regmap
cannot use.

Drop the stale check and let devm_regmap_init_i2c() validate and select
the supported transfer method.

Fixes: 6455a8a84bdfd ("power: supply: max17040: Use regmap i2c")
Cc: stable@vger.kernel.org
Signed-off-by: Jianing Li <m13940358460@163.com>
Link: https://patch.msgid.link/20260731084259.916-1-m13940358460@163.com
[Fixed Fixes tag, so that it points to the regmap introduction instead of the initial driver addition]
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/max17040_battery.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index d1075959dd466..29684d922893c 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -433,16 +433,12 @@ static const struct power_supply_desc max17040_battery_desc = {
 static int max17040_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
-	struct i2c_adapter *adapter = client->adapter;
 	struct power_supply_config psy_cfg = {};
 	struct max17040_chip *chip;
 	enum chip_id chip_id;
 	bool enable_irq = false;
 	int ret;
 
-	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
-		return -EIO;
-
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
-- 
2.53.0