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Date:   Fri, 10 Jun 2022 09:47:34 +0300
From:   Heikki Krogerus <heikki.krogerus@linux.intel.com>
To:     "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc:     Linux ACPI <linux-acpi@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org
Subject: Re: [PATCH v1 05/16] USB: ACPI: Use acpi_find_child_by_adr()
Message-ID: <YqLpBp0NYhOCCd2X@kuha.fi.intel.com>
References: <1843211.tdWV9SEqCh@kreacher>
 <3459925.iIbC2pHGDl@kreacher>
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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,

-- 
heikki