[PATCH v2 0/2] serdev: bus-code clean ups

[PATCH v2 0/2] serdev: bus-code clean ups

[Johan Hovold]

As noted by Hans, we currently fail to generate uevents for ACPI serdev
controller as they do not have any ACPI companions from which ACPI
modaliases are constructed.

In fact, we should not have been generating modaliases for controllers
in the first place as controllers are not bound to drivers.

This series applies on top of Hans's minimal fix which suppresses the
uevent errors for ACPI controllers (even though it could replace it
entirely if preferred).

Johan


v2
 - add the missing static keyword for the modalias attribute when moving
   the definition (noted by Greg)


Johan Hovold (2):
  serdev: do not generate modaliases for controllers
  serdev: only match serdev devices

 drivers/tty/serdev/core.c | 80 +++++++++++++++++++++++++----------------------
 1 file changed, 42 insertions(+), 38 deletions(-)

-- 
2.15.1

[PATCH v2 1/2] serdev: do not generate modaliases for controllers

[Johan Hovold]

Serdev controllers are not bound to any drivers and it therefore makes
no sense to generate modaliases for them.

This has already been fixed separately for ACPI controllers for which
uevent errors were also being logged during probe due to the missing
ACPI companions (from which ACPI modaliases are generated).

This patch moves the modalias handling from the bus type to the client
device type. Specifically, this means that only serdev devices (a.k.a.
clients or slaves) will have have MODALIAS fields in their uevent
environments and corresponding modalias sysfs attributes.

Also add the missing static keyword for the modalias device attribute
when moving the definition.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/serdev/core.c | 72 ++++++++++++++++++++++-------------------------
 1 file changed, 34 insertions(+), 38 deletions(-)

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 5dc88f61f506..c8c43834477b 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -19,6 +19,38 @@
 static bool is_registered;
 static DEFINE_IDA(ctrl_ida);
 
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+	if (len != -ENODEV)
+		return len;
+
+	return of_device_modalias(dev, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *serdev_device_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(serdev_device);
+
+static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	int rc;
+
+	/* TODO: platform modalias */
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
+
+	return of_device_uevent_modalias(dev, env);
+}
+
 static void serdev_device_release(struct device *dev)
 {
 	struct serdev_device *serdev = to_serdev_device(dev);
@@ -26,6 +58,8 @@ static void serdev_device_release(struct device *dev)
 }
 
 static const struct device_type serdev_device_type = {
+	.groups		= serdev_device_groups,
+	.uevent		= serdev_device_uevent,
 	.release	= serdev_device_release,
 };
 
@@ -49,23 +83,6 @@ static int serdev_device_match(struct device *dev, struct device_driver *drv)
 	return of_driver_match_device(dev, drv);
 }
 
-static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
-{
-	int rc;
-
-	/* TODO: platform modalias */
-
-	/* ACPI enumerated controllers do not have a modalias */
-	if (!dev->of_node && dev->type == &serdev_ctrl_type)
-		return 0;
-
-	rc = acpi_device_uevent_modalias(dev, env);
-	if (rc != -ENODEV)
-		return rc;
-
-	return of_device_uevent_modalias(dev, env);
-}
-
 /**
  * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
  * @serdev:	serdev_device to be added
@@ -305,32 +322,11 @@ static int serdev_drv_remove(struct device *dev)
 	return 0;
 }
 
-static ssize_t modalias_show(struct device *dev,
-			     struct device_attribute *attr, char *buf)
-{
-	int len;
-
-	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
-	if (len != -ENODEV)
-		return len;
-
-	return of_device_modalias(dev, buf, PAGE_SIZE);
-}
-DEVICE_ATTR_RO(modalias);
-
-static struct attribute *serdev_device_attrs[] = {
-	&dev_attr_modalias.attr,
-	NULL,
-};
-ATTRIBUTE_GROUPS(serdev_device);
-
 static struct bus_type serdev_bus_type = {
 	.name		= "serial",
 	.match		= serdev_device_match,
 	.probe		= serdev_drv_probe,
 	.remove		= serdev_drv_remove,
-	.uevent		= serdev_uevent,
-	.dev_groups	= serdev_device_groups,
 };
 
 /**
-- 
2.15.1

[PATCH v2 2/2] serdev: only match serdev devices

[Johan Hovold]

Only serdev devices (a.k.a. clients or slaves) are bound to drivers so
bail out early from match() in case the device is not a serdev device
(i.e. if it's a serdev controller).

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/serdev/core.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index c8c43834477b..f710862f5c06 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -63,6 +63,11 @@ static const struct device_type serdev_device_type = {
 	.release	= serdev_device_release,
 };
 
+static bool is_serdev_device(const struct device *dev)
+{
+	return dev->type == &serdev_device_type;
+}
+
 static void serdev_ctrl_release(struct device *dev)
 {
 	struct serdev_controller *ctrl = to_serdev_controller(dev);
@@ -76,6 +81,9 @@ static const struct device_type serdev_ctrl_type = {
 
 static int serdev_device_match(struct device *dev, struct device_driver *drv)
 {
+	if (!is_serdev_device(dev))
+		return 0;
+
 	/* TODO: platform matching */
 	if (acpi_driver_match_device(dev, drv))
 		return 1;
-- 
2.15.1

Re: [PATCH v2 1/2] serdev: do not generate modaliases for controllers

[Sebastian Reichel]

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Hi,

On Tue, Jan 09, 2018 at 05:09:16PM +0100, Johan Hovold wrote:
> Serdev controllers are not bound to any drivers and it therefore makes
> no sense to generate modaliases for them.
> 
> This has already been fixed separately for ACPI controllers for which
> uevent errors were also being logged during probe due to the missing
> ACPI companions (from which ACPI modaliases are generated).
> 
> This patch moves the modalias handling from the bus type to the client
> device type. Specifically, this means that only serdev devices (a.k.a.
> clients or slaves) will have have MODALIAS fields in their uevent
> environments and corresponding modalias sysfs attributes.
> 
> Also add the missing static keyword for the modalias device attribute
> when moving the definition.
> 
> Reported-by: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

>  drivers/tty/serdev/core.c | 72 ++++++++++++++++++++++-------------------------
>  1 file changed, 34 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
> index 5dc88f61f506..c8c43834477b 100644
> --- a/drivers/tty/serdev/core.c
> +++ b/drivers/tty/serdev/core.c
> @@ -19,6 +19,38 @@
>  static bool is_registered;
>  static DEFINE_IDA(ctrl_ida);
>  
> +static ssize_t modalias_show(struct device *dev,
> +			     struct device_attribute *attr, char *buf)
> +{
> +	int len;
> +
> +	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
> +	if (len != -ENODEV)
> +		return len;
> +
> +	return of_device_modalias(dev, buf, PAGE_SIZE);
> +}
> +static DEVICE_ATTR_RO(modalias);
> +
> +static struct attribute *serdev_device_attrs[] = {
> +	&dev_attr_modalias.attr,
> +	NULL,
> +};
> +ATTRIBUTE_GROUPS(serdev_device);
> +
> +static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
> +{
> +	int rc;
> +
> +	/* TODO: platform modalias */
> +
> +	rc = acpi_device_uevent_modalias(dev, env);
> +	if (rc != -ENODEV)
> +		return rc;
> +
> +	return of_device_uevent_modalias(dev, env);
> +}
> +
>  static void serdev_device_release(struct device *dev)
>  {
>  	struct serdev_device *serdev = to_serdev_device(dev);
> @@ -26,6 +58,8 @@ static void serdev_device_release(struct device *dev)
>  }
>  
>  static const struct device_type serdev_device_type = {
> +	.groups		= serdev_device_groups,
> +	.uevent		= serdev_device_uevent,
>  	.release	= serdev_device_release,
>  };
>  
> @@ -49,23 +83,6 @@ static int serdev_device_match(struct device *dev, struct device_driver *drv)
>  	return of_driver_match_device(dev, drv);
>  }
>  
> -static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
> -{
> -	int rc;
> -
> -	/* TODO: platform modalias */
> -
> -	/* ACPI enumerated controllers do not have a modalias */
> -	if (!dev->of_node && dev->type == &serdev_ctrl_type)
> -		return 0;
> -
> -	rc = acpi_device_uevent_modalias(dev, env);
> -	if (rc != -ENODEV)
> -		return rc;
> -
> -	return of_device_uevent_modalias(dev, env);
> -}
> -
>  /**
>   * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
>   * @serdev:	serdev_device to be added
> @@ -305,32 +322,11 @@ static int serdev_drv_remove(struct device *dev)
>  	return 0;
>  }
>  
> -static ssize_t modalias_show(struct device *dev,
> -			     struct device_attribute *attr, char *buf)
> -{
> -	int len;
> -
> -	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
> -	if (len != -ENODEV)
> -		return len;
> -
> -	return of_device_modalias(dev, buf, PAGE_SIZE);
> -}
> -DEVICE_ATTR_RO(modalias);
> -
> -static struct attribute *serdev_device_attrs[] = {
> -	&dev_attr_modalias.attr,
> -	NULL,
> -};
> -ATTRIBUTE_GROUPS(serdev_device);
> -
>  static struct bus_type serdev_bus_type = {
>  	.name		= "serial",
>  	.match		= serdev_device_match,
>  	.probe		= serdev_drv_probe,
>  	.remove		= serdev_drv_remove,
> -	.uevent		= serdev_uevent,
> -	.dev_groups	= serdev_device_groups,
>  };
>  
>  /**
> -- 
> 2.15.1
> 

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Re: [PATCH v2 2/2] serdev: only match serdev devices

[Sebastian Reichel]

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Hi,

On Tue, Jan 09, 2018 at 05:09:17PM +0100, Johan Hovold wrote:
> Only serdev devices (a.k.a. clients or slaves) are bound to drivers so
> bail out early from match() in case the device is not a serdev device
> (i.e. if it's a serdev controller).
> 
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

>  drivers/tty/serdev/core.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
> index c8c43834477b..f710862f5c06 100644
> --- a/drivers/tty/serdev/core.c
> +++ b/drivers/tty/serdev/core.c
> @@ -63,6 +63,11 @@ static const struct device_type serdev_device_type = {
>  	.release	= serdev_device_release,
>  };
>  
> +static bool is_serdev_device(const struct device *dev)
> +{
> +	return dev->type == &serdev_device_type;
> +}
> +
>  static void serdev_ctrl_release(struct device *dev)
>  {
>  	struct serdev_controller *ctrl = to_serdev_controller(dev);
> @@ -76,6 +81,9 @@ static const struct device_type serdev_ctrl_type = {
>  
>  static int serdev_device_match(struct device *dev, struct device_driver *drv)
>  {
> +	if (!is_serdev_device(dev))
> +		return 0;
> +
>  	/* TODO: platform matching */
>  	if (acpi_driver_match_device(dev, drv))
>  		return 1;
> -- 
> 2.15.1
> 

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