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Commit 0846e7e9 authored by Matthew Garrett's avatar Matthew Garrett Committed by Greg Kroah-Hartman
Browse files

usb: Add support for indicating whether a port is removable 



Userspace may want to make policy decisions based on whether or not a
given USB device is removable. Add a per-device member and support
for exposing it in sysfs. Information sources to populate it will be
added later.

Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent af74d2da

Documentation/ABI/testing/sysfs-bus-usb

+11 −0
Original line number Diff line number Diff line
@@ -182,3 +182,14 @@ Description: 
		USB2 hardware LPM is enabled for the device. Developer can

		write y/Y/1 or n/N/0 to the file to enable/disable the

		feature.



What:		/sys/bus/usb/devices/.../removable

Date:		February 2012

Contact:	Matthew Garrett <mjg@redhat.com>

Description:

		Some information about whether a given USB device is

		physically fixed to the platform can be inferred from a

		combination of hub decriptor bits and platform-specific data

		such as ACPI. This file will read either "removable" or

		"fixed" if the information is available, and "unknown"

		otherwise.
 
 No newline at end of file

drivers/usb/core/sysfs.c

+23 −0
Original line number Diff line number Diff line
@@ -230,6 +230,28 @@ show_urbnum(struct device *dev, struct device_attribute *attr, char *buf) 
}

static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);



static ssize_t

show_removable(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct usb_device *udev;

	char *state;



	udev = to_usb_device(dev);



	switch (udev->removable) {

	case USB_DEVICE_REMOVABLE:

		state = "removable";

		break;

	case USB_DEVICE_FIXED:

		state = "fixed";

		break;

	default:

		state = "unknown";

	}



	return sprintf(buf, "%s\n", state);

}

static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);



#ifdef	CONFIG_PM
@@ -626,6 +648,7 @@ static struct attribute *dev_attrs[] = { 
	&dev_attr_avoid_reset_quirk.attr,

	&dev_attr_authorized.attr,

	&dev_attr_remove.attr,

	&dev_attr_removable.attr,

	NULL,

};

static struct attribute_group dev_attr_grp = {

include/linux/usb.h

+8 −0
Original line number Diff line number Diff line
@@ -376,6 +376,12 @@ struct usb_bus { 


struct usb_tt;



enum usb_device_removable {

	USB_DEVICE_REMOVABLE_UNKNOWN = 0,

	USB_DEVICE_REMOVABLE,

	USB_DEVICE_FIXED,

};



/**

 * struct usb_device - kernel's representation of a USB device

 * @devnum: device number; address on a USB bus
@@ -432,6 +438,7 @@ struct usb_tt; 
 * @wusb_dev: if this is a Wireless USB device, link to the WUSB

 *	specific data for the device.

 * @slot_id: Slot ID assigned by xHCI

 * @removable: Device can be physically removed from this port

 *

 * Notes:

 * Usbcore drivers should not set usbdev->state directly.  Instead use
@@ -509,6 +516,7 @@ struct usb_device { 
#endif

	struct wusb_dev *wusb_dev;

	int slot_id;

	enum usb_device_removable removable;

};

#define	to_usb_device(d) container_of(d, struct usb_device, dev)