diff mbox series

[v2,05/16] USB: ACPI: Replace usb_acpi_find_port() with acpi_find_child_by_adr()

Message ID 23334378.ouqheUzb2q@kreacher
State New
Headers show
Series ACPI: Get rid of the list of children in struct acpi_device | expand

Commit Message

Rafael J. Wysocki June 13, 2022, 6:39 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of walking the list of children of an ACPI device directly
in order to find the child matching a given bus address, use
acpi_find_child_by_adr() for this purpose.

Also notice that if acpi_find_child_by_adr() doesn't find a matching
child, acpi_find_child_device() will not find it too, so directly
replace usb_acpi_find_port() in usb_acpi_get_companion_for_port() with
acpi_find_child_by_adr() and drop it entirely.

Apart from simplifying the code, this will help to eliminate the
children list head from struct acpi_device as it is redundant and it
is used in questionable ways in some places (in particular, locking is
needed for walking the list pointed to it safely, but it is often
missing).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2:
   * Drop usb_acpi_find_port() (Heikki, Andy).
   * Change the subject accordingly.

---
 drivers/usb/core/usb-acpi.c |   18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

Comments

Heikki Krogerus June 14, 2022, 7:37 a.m. UTC | #1 
On Mon, Jun 13, 2022 at 08:39:37PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Instead of walking the list of children of an ACPI device directly
> in order to find the child matching a given bus address, use
> acpi_find_child_by_adr() for this purpose.
> 
> Also notice that if acpi_find_child_by_adr() doesn't find a matching
> child, acpi_find_child_device() will not find it too, so directly
> replace usb_acpi_find_port() in usb_acpi_get_companion_for_port() with
> acpi_find_child_by_adr() and drop it entirely.
> 
> Apart from simplifying the code, this will help to eliminate the
> children list head from struct acpi_device as it is redundant and it
> is used in questionable ways in some places (in particular, locking is
> needed for walking the list pointed to it safely, but it is often
> missing).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
> 
> v1 -> v2:
>    * Drop usb_acpi_find_port() (Heikki, Andy).
>    * Change the subject accordingly.
> 
> ---
>  drivers/usb/core/usb-acpi.c |   18 +-----------------
>  1 file changed, 1 insertion(+), 17 deletions(-)
> 
> Index: linux-pm/drivers/usb/core/usb-acpi.c
> ===================================================================
> --- linux-pm.orig/drivers/usb/core/usb-acpi.c
> +++ linux-pm/drivers/usb/core/usb-acpi.c
> @@ -124,22 +124,6 @@ out:
>   */
>  #define USB_ACPI_LOCATION_VALID (1 << 31)
>  
> -static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
> -					      int raw)
> -{
> -	struct acpi_device *adev;
> -
> -	if (!parent)
> -		return NULL;
> -
> -	list_for_each_entry(adev, &parent->children, node) {
> -		if (acpi_device_adr(adev) == raw)
> -			return adev;
> -	}
> -
> -	return acpi_find_child_device(parent, raw, false);
> -}
> -
>  static struct acpi_device *
>  usb_acpi_get_companion_for_port(struct usb_port *port_dev)
>  {
> @@ -170,7 +154,7 @@ usb_acpi_get_companion_for_port(struct u
>  		port1 = port_dev->portnum;
>  	}
>  
> -	return usb_acpi_find_port(adev, port1);
> +	return acpi_find_child_by_adr(adev, port1);
>  }
>  
>  static struct acpi_device *
> 
>
diff mbox series

Patch

Index: linux-pm/drivers/usb/core/usb-acpi.c
===================================================================
--- linux-pm.orig/drivers/usb/core/usb-acpi.c
+++ linux-pm/drivers/usb/core/usb-acpi.c
@@ -124,22 +124,6 @@  out:
  */
 #define USB_ACPI_LOCATION_VALID (1 << 31)
 
-static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
-					      int raw)
-{
-	struct acpi_device *adev;
-
-	if (!parent)
-		return NULL;
-
-	list_for_each_entry(adev, &parent->children, node) {
-		if (acpi_device_adr(adev) == raw)
-			return adev;
-	}
-
-	return acpi_find_child_device(parent, raw, false);
-}
-
 static struct acpi_device *
 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
 {
@@ -170,7 +154,7 @@  usb_acpi_get_companion_for_port(struct u
 		port1 = port_dev->portnum;
 	}
 
-	return usb_acpi_find_port(adev, port1);
+	return acpi_find_child_by_adr(adev, port1);
 }
 
 static struct acpi_device *