diff mbox series

[v1,05/16] USB: ACPI: Use acpi_find_child_by_adr()

Message ID 3459925.iIbC2pHGDl@kreacher (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Rafael J. Wysocki June 9, 2022, 1:56 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.

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>
---
 drivers/usb/core/usb-acpi.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

Comments

Andy Shevchenko June 9, 2022, 3:27 p.m. UTC | #1
On Thu, Jun 09, 2022 at 03:56:42PM +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.

...

>  	if (!parent)
>  		return NULL;

Can be removed because it's embedded in the call below, no?

> +	return acpi_find_child_by_adr(parent, raw);
Rafael J. Wysocki June 9, 2022, 3:37 p.m. UTC | #2
On Thu, Jun 9, 2022 at 5:27 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Thu, Jun 09, 2022 at 03:56:42PM +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.
>
> ...
>
> >       if (!parent)
> >               return NULL;
>
> Can be removed because it's embedded in the call below, no?

Yes, it can, in analogy with the thunderbolt code.  Will update.

> > +     return acpi_find_child_by_adr(parent, raw);
>
> --
Heikki Krogerus June 10, 2022, 6:47 a.m. UTC | #3
On Thu, Jun 09, 2022 at 03:56:42PM +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.
> 
> 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>
> ---
>  drivers/usb/core/usb-acpi.c |    9 +--------
>  1 file changed, 1 insertion(+), 8 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
> @@ -127,17 +127,10 @@ out:
>  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);
> +	return acpi_find_child_by_adr(parent, raw);
>  }
>  
>  static struct acpi_device *

I think usb_acpi_find_port() can also be dropped now.

thanks,
Rafael J. Wysocki June 10, 2022, 1:14 p.m. UTC | #4
On Fri, Jun 10, 2022 at 8:47 AM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> On Thu, Jun 09, 2022 at 03:56:42PM +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.
> >
> > 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>
> > ---
> >  drivers/usb/core/usb-acpi.c |    9 +--------
> >  1 file changed, 1 insertion(+), 8 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
> > @@ -127,17 +127,10 @@ out:
> >  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);
> > +     return acpi_find_child_by_adr(parent, raw);
> >  }
> >
> >  static struct acpi_device *
>
> I think usb_acpi_find_port() can also be dropped now.

Yes, it can.

I'm dropping it in the new version of the patch to be posted.
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
@@ -127,17 +127,10 @@  out:
 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);
+	return acpi_find_child_by_adr(parent, raw);
 }
 
 static struct acpi_device *