[PATCH 0/3] i3c: master: Small fixes for dev_nack_retry_count

[PATCH 0/3] i3c: master: Small fixes for dev_nack_retry_count

[Adrian Hunter]

Hi

Here are some small fixes for dev_nack_retry_count.


Adrian Hunter (3):
      i3c: master: Update dev_nack_retry_count under maintenance lock
      i3c: master: Add missing runtime PM get in dev_nack_retry_count_store()
      i3c: master: Use unsigned int for dev_nack_retry_count consistently

 drivers/i3c/master.c               | 26 ++++++++++++++++++--------
 drivers/i3c/master/dw-i3c-master.c |  4 ++--
 include/linux/i3c/master.h         |  2 +-
 3 files changed, 21 insertions(+), 11 deletions(-)


Regards
Adrian

[PATCH 1/3] i3c: master: Update dev_nack_retry_count under maintenance lock

[Adrian Hunter]

Protect master->dev_nack_retry_count against concurrent sysfs updates
by updating it while holding the bus maintenance lock.

Consequently, combine adjacent return statements into one.

For consistency, read dev_nack_retry_count while holding the bus normaluse
lock.

Fixes: b58f47eb39268 ("i3c: add sysfs entry and attribute for Device NACK Retry count")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/i3c/master.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 367e0d6d4a64..66cf5d3bd987 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -744,7 +744,14 @@ static DEVICE_ATTR_RW(hotjoin);
 static ssize_t dev_nack_retry_count_show(struct device *dev,
 					 struct device_attribute *attr, char *buf)
 {
-	return sysfs_emit(buf, "%u\n", dev_to_i3cmaster(dev)->dev_nack_retry_count);
+	struct i3c_bus *i3cbus = dev_to_i3cbus(dev);
+	ssize_t ret;
+
+	i3c_bus_normaluse_lock(i3cbus);
+	ret = sysfs_emit(buf, "%u\n", dev_to_i3cmaster(dev)->dev_nack_retry_count);
+	i3c_bus_normaluse_unlock(i3cbus);
+
+	return ret;
 }
 
 static ssize_t dev_nack_retry_count_store(struct device *dev,
@@ -762,14 +769,11 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
 
 	i3c_bus_maintenance_lock(i3cbus);
 	ret = master->ops->set_dev_nack_retry(master, val);
+	if (!ret)
+		master->dev_nack_retry_count = val;
 	i3c_bus_maintenance_unlock(i3cbus);
 
-	if (ret)
-		return ret;
-
-	master->dev_nack_retry_count = val;
-
-	return count;
+	return ret ?: count;
 }
 
 static DEVICE_ATTR_RW(dev_nack_retry_count);
-- 
2.51.0

Re: [PATCH 1/3] i3c: master: Update dev_nack_retry_count under maintenance lock

[Frank Li]

On Tue, Jun 16, 2026 at 02:37:50PM +0300, Adrian Hunter wrote:
> Protect master->dev_nack_retry_count against concurrent sysfs updates
> by updating it while holding the bus maintenance lock.
>
> Consequently, combine adjacent return statements into one.
>
> For consistency, read dev_nack_retry_count while holding the bus normaluse
> lock.
>
> Fixes: b58f47eb39268 ("i3c: add sysfs entry and attribute for Device NACK Retry count")
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/i3c/master.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 367e0d6d4a64..66cf5d3bd987 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -744,7 +744,14 @@ static DEVICE_ATTR_RW(hotjoin);
>  static ssize_t dev_nack_retry_count_show(struct device *dev,
>  					 struct device_attribute *attr, char *buf)
>  {
> -	return sysfs_emit(buf, "%u\n", dev_to_i3cmaster(dev)->dev_nack_retry_count);
> +	struct i3c_bus *i3cbus = dev_to_i3cbus(dev);
> +	ssize_t ret;
> +
> +	i3c_bus_normaluse_lock(i3cbus);
> +	ret = sysfs_emit(buf, "%u\n", dev_to_i3cmaster(dev)->dev_nack_retry_count);
> +	i3c_bus_normaluse_unlock(i3cbus);
> +
> +	return ret;
>  }
>
>  static ssize_t dev_nack_retry_count_store(struct device *dev,
> @@ -762,14 +769,11 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
>
>  	i3c_bus_maintenance_lock(i3cbus);
>  	ret = master->ops->set_dev_nack_retry(master, val);
> +	if (!ret)
> +		master->dev_nack_retry_count = val;
>  	i3c_bus_maintenance_unlock(i3cbus);
>
> -	if (ret)
> -		return ret;
> -
> -	master->dev_nack_retry_count = val;
> -
> -	return count;
> +	return ret ?: count;
>  }
>
>  static DEVICE_ATTR_RW(dev_nack_retry_count);
> --
> 2.51.0
>

[PATCH 2/3] i3c: master: Add missing runtime PM get in dev_nack_retry_count_store()

[Adrian Hunter]

Ensure the device is runtime resumed while updating the retry
configuration to avoid accessing the controller while suspended.

Call i3c_master_rpm_get() before accessing the controller in
dev_nack_retry_count_store() and release it with
i3c_master_rpm_put() afterwards.

Fixes: 990c149c61ee4 ("i3c: master: Introduce optional Runtime PM support")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/i3c/master.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 66cf5d3bd987..903ac01ab413 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -767,12 +767,18 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
 	if (ret)
 		return ret;
 
+	ret = i3c_master_rpm_get(master);
+	if (ret)
+		return ret;
+
 	i3c_bus_maintenance_lock(i3cbus);
 	ret = master->ops->set_dev_nack_retry(master, val);
 	if (!ret)
 		master->dev_nack_retry_count = val;
 	i3c_bus_maintenance_unlock(i3cbus);
 
+	i3c_master_rpm_put(master);
+
 	return ret ?: count;
 }
 
-- 
2.51.0

Re: [PATCH 2/3] i3c: master: Add missing runtime PM get in dev_nack_retry_count_store()

[Frank Li]

On Tue, Jun 16, 2026 at 02:37:51PM +0300, Adrian Hunter wrote:
> Ensure the device is runtime resumed while updating the retry
> configuration to avoid accessing the controller while suspended.
>
> Call i3c_master_rpm_get() before accessing the controller in
> dev_nack_retry_count_store() and release it with
> i3c_master_rpm_put() afterwards.
>
> Fixes: 990c149c61ee4 ("i3c: master: Introduce optional Runtime PM support")
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/i3c/master.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 66cf5d3bd987..903ac01ab413 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -767,12 +767,18 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
>  	if (ret)
>  		return ret;
>
> +	ret = i3c_master_rpm_get(master);
> +	if (ret)
> +		return ret;
> +
>  	i3c_bus_maintenance_lock(i3cbus);
>  	ret = master->ops->set_dev_nack_retry(master, val);
>  	if (!ret)
>  		master->dev_nack_retry_count = val;
>  	i3c_bus_maintenance_unlock(i3cbus);
>
> +	i3c_master_rpm_put(master);
> +
>  	return ret ?: count;
>  }
>
> --
> 2.51.0
>

[PATCH 3/3] i3c: master: Use unsigned int for dev_nack_retry_count consistently

[Adrian Hunter]

Use unsigned int for dev_nack_retry_count across the core and
controller drivers to match the type of master->dev_nack_retry_count.

Update the sysfs store path to use kstrtouint() and adjust the
 ->set_dev_nack_retry() callback prototype and callers accordingly.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/i3c/master.c               | 4 ++--
 drivers/i3c/master/dw-i3c-master.c | 4 ++--
 include/linux/i3c/master.h         | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 903ac01ab413..58d20624ed05 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -760,10 +760,10 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
 {
 	struct i3c_bus *i3cbus = dev_to_i3cbus(dev);
 	struct i3c_master_controller *master = dev_to_i3cmaster(dev);
-	unsigned long val;
+	unsigned int val;
 	int ret;
 
-	ret = kstrtoul(buf, 0, &val);
+	ret = kstrtouint(buf, 0, &val);
 	if (ret)
 		return ret;
 
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index c7030d0cd8a6..e4f6d6f29ed5 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1481,7 +1481,7 @@ static irqreturn_t dw_i3c_master_irq_handler(int irq, void *dev_id)
 }
 
 static int dw_i3c_master_set_dev_nack_retry(struct i3c_master_controller *m,
-					    unsigned long dev_nack_retry_cnt)
+					    unsigned int dev_nack_retry_cnt)
 {
 	struct dw_i3c_master *master = to_dw_i3c_master(m);
 	u32 reg;
@@ -1489,7 +1489,7 @@ static int dw_i3c_master_set_dev_nack_retry(struct i3c_master_controller *m,
 
 	if (dev_nack_retry_cnt > DW_I3C_DEV_NACK_RETRY_CNT_MAX) {
 		dev_err(&master->base.dev,
-			"Value %ld exceeds maximum %d\n",
+			"Value %u exceeds maximum %d\n",
 			dev_nack_retry_cnt, DW_I3C_DEV_NACK_RETRY_CNT_MAX);
 		return -ERANGE;
 	}
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index f73cede87d36..6f0379bdbb6d 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -494,7 +494,7 @@ struct i3c_master_controller_ops {
 	int (*disable_hotjoin)(struct i3c_master_controller *master);
 	int (*set_speed)(struct i3c_master_controller *master, enum i3c_open_drain_speed speed);
 	int (*set_dev_nack_retry)(struct i3c_master_controller *master,
-				  unsigned long dev_nack_retry_cnt);
+				  unsigned int dev_nack_retry_cnt);
 };
 
 /**
-- 
2.51.0

Re: [PATCH 3/3] i3c: master: Use unsigned int for dev_nack_retry_count consistently

[Frank Li]

On Tue, Jun 16, 2026 at 02:37:52PM +0300, Adrian Hunter wrote:
> Use unsigned int for dev_nack_retry_count across the core and
> controller drivers to match the type of master->dev_nack_retry_count.
>
> Update the sysfs store path to use kstrtouint() and adjust the
>  ->set_dev_nack_retry() callback prototype and callers accordingly.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
Reviewed-by: Frank Li <Frank.Li@nxp.com>
>  drivers/i3c/master.c               | 4 ++--
>  drivers/i3c/master/dw-i3c-master.c | 4 ++--
>  include/linux/i3c/master.h         | 2 +-
>  3 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 903ac01ab413..58d20624ed05 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -760,10 +760,10 @@ static ssize_t dev_nack_retry_count_store(struct device *dev,
>  {
>  	struct i3c_bus *i3cbus = dev_to_i3cbus(dev);
>  	struct i3c_master_controller *master = dev_to_i3cmaster(dev);
> -	unsigned long val;
> +	unsigned int val;
>  	int ret;
>
> -	ret = kstrtoul(buf, 0, &val);
> +	ret = kstrtouint(buf, 0, &val);
>  	if (ret)
>  		return ret;
>
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index c7030d0cd8a6..e4f6d6f29ed5 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -1481,7 +1481,7 @@ static irqreturn_t dw_i3c_master_irq_handler(int irq, void *dev_id)
>  }
>
>  static int dw_i3c_master_set_dev_nack_retry(struct i3c_master_controller *m,
> -					    unsigned long dev_nack_retry_cnt)
> +					    unsigned int dev_nack_retry_cnt)
>  {
>  	struct dw_i3c_master *master = to_dw_i3c_master(m);
>  	u32 reg;
> @@ -1489,7 +1489,7 @@ static int dw_i3c_master_set_dev_nack_retry(struct i3c_master_controller *m,
>
>  	if (dev_nack_retry_cnt > DW_I3C_DEV_NACK_RETRY_CNT_MAX) {
>  		dev_err(&master->base.dev,
> -			"Value %ld exceeds maximum %d\n",
> +			"Value %u exceeds maximum %d\n",
>  			dev_nack_retry_cnt, DW_I3C_DEV_NACK_RETRY_CNT_MAX);
>  		return -ERANGE;
>  	}
> diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
> index f73cede87d36..6f0379bdbb6d 100644
> --- a/include/linux/i3c/master.h
> +++ b/include/linux/i3c/master.h
> @@ -494,7 +494,7 @@ struct i3c_master_controller_ops {
>  	int (*disable_hotjoin)(struct i3c_master_controller *master);
>  	int (*set_speed)(struct i3c_master_controller *master, enum i3c_open_drain_speed speed);
>  	int (*set_dev_nack_retry)(struct i3c_master_controller *master,
> -				  unsigned long dev_nack_retry_cnt);
> +				  unsigned int dev_nack_retry_cnt);
>  };
>
>  /**
> --
> 2.51.0
>