USB: set default y for CONFIG_USB_DEVICE_CLASS

USB: set default y for CONFIG_USB_DEVICE_CLASS

[Kay Sievers]

From: Kay Sievers <kay.sievers@vrfy.org>
Subject: USB: set default y for CONFIG_USB_DEVICE_CLASS

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
---

diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index f493fb1..346fc03 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -40,21 +40,25 @@ config USB_DEVICEFS
 config USB_DEVICE_CLASS
 	bool "USB device class-devices (DEPRECATED)"
 	depends on USB
-	default n
+	default y
 	---help---
 	  Userspace access to USB devices is granted by device-nodes exported
 	  directly from the usbdev in sysfs. Old versions of the driver
 	  core and udev needed additional class devices to export device nodes.
 
 	  These additional devices are difficult to handle in userspace, if
-	  information about USB interfaces must be available. One device contains
-	  the device node, the other device contains the interface data. Both
-	  devices are at the same level in sysfs (siblings) and one can't access
-	  the other. The device node created directly by the usbdev is the parent
-	  device of the interface and therefore easily accessible from the interface
-	  event.
-
-	  This option provides backward compatibility if needed.
+	  information about USB interfaces must be available. One device
+	  contains the device node, the other device contains the interface
+	  data. Both devices are at the same level in sysfs (siblings) and one
+	  can't access the other. The device node created directly by the
+	  usb device is the parent device of the interface and therefore
+	  easily accessible from the interface event.
+
+	  This option provides backward compatibility for libusb device
+	  nodes (lsusb) when usbfs is not used, and the following udev rule
+	  doesn't exist:
+	    SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \
+	    NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644"
 
 config USB_DYNAMIC_MINORS
 	bool "Dynamic USB minor allocation (EXPERIMENTAL)"

Re: USB: set default y for CONFIG_USB_DEVICE_CLASS

[Jesper Juhl]

On 27/05/07, Kay Sievers <kay.sievers@vrfy.org> wrote:
> From: Kay Sievers <kay.sievers@vrfy.org>
> Subject: USB: set default y for CONFIG_USB_DEVICE_CLASS
>
> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
> ---
>
> diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
> index f493fb1..346fc03 100644
> --- a/drivers/usb/core/Kconfig
> +++ b/drivers/usb/core/Kconfig
> @@ -40,21 +40,25 @@ config USB_DEVICEFS
>  config USB_DEVICE_CLASS
>         bool "USB device class-devices (DEPRECATED)"
>         depends on USB
> -       default n
> +       default y

It puzzles me why a deprecated option should be default 'Y'...

-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
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Re: USB: set default y for CONFIG_USB_DEVICE_CLASS

[bert hubert]

On Sun, May 27, 2007 at 06:10:41PM +0200, Jesper Juhl wrote:
> >        bool "USB device class-devices (DEPRECATED)"
> >        depends on USB
> >-       default n
> >+       default y
> 
> It puzzles me why a deprecated option should be default 'Y'...

Because if it defaults to 'n', a 'make oldconfig' will break unmodified
userspace on reboot, which is something we don't want to do in a 'stable'
series, without announcing it first for a serious length of time.

	Bert

-- 
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http://netherlabs.nl              Open and Closed source services

Re: USB: set default y for CONFIG_USB_DEVICE_CLASS

[Kay Sievers]

On Sun, 2007-05-27 at 18:10 +0200, Jesper Juhl wrote:
> On 27/05/07, Kay Sievers <kay.sievers@vrfy.org> wrote:
> > From: Kay Sievers <kay.sievers@vrfy.org>
> > Subject: USB: set default y for CONFIG_USB_DEVICE_CLASS
> >
> > Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
> > ---
> >
> > diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
> > index f493fb1..346fc03 100644
> > --- a/drivers/usb/core/Kconfig
> > +++ b/drivers/usb/core/Kconfig
> > @@ -40,21 +40,25 @@ config USB_DEVICEFS
> >  config USB_DEVICE_CLASS
> >         bool "USB device class-devices (DEPRECATED)"
> >         depends on USB
> > -       default n
> > +       default y
> 
> It puzzles me why a deprecated option should be default 'Y'...

Because usb_device class devices are kind of broken regarding the event
timing, and should not be used anymore. They are replaced by
device-nodes created by the real usb-device, but some systems still
depend on the class devices:
   http://lkml.org/lkml/2007/5/27/56

We better default to y for a while until the users have switched over.

Kay