Commit ef955341 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
Browse files

USB: Export QUIRK_RESET_MORPHS through sysfs 



Some devices which use mode switching revert to their
primary mode as they are reset. They must not be reset for
error handling. As user spaces makes the switch it also
has to tell the kernel that a device is quirky.

Signed-off-by: default avatarOliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 5d398779

Documentation/ABI/testing/sysfs-bus-usb

+11 −0
Original line number Diff line number Diff line
@@ -159,3 +159,14 @@ Description: 
		device.  This is useful to ensure auto probing won't

		match the driver to the device.  For example:

		# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id



What:		/sys/bus/usb/device/.../avoid_reset

Date:		December 2009

Contact:	Oliver Neukum <oliver@neukum.org>

Description:

		Writing 1 to this file tells the kernel that this

		device will morph into another mode when it is reset.

		Drivers will not use reset for error handling for

		such devices.

Users:

		usb_modeswitch

drivers/usb/core/sysfs.c

+31 −0
Original line number Diff line number Diff line
@@ -190,6 +190,36 @@ show_quirks(struct device *dev, struct device_attribute *attr, char *buf) 
}

static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);



static ssize_t

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

{

	struct usb_device *udev;



	udev = to_usb_device(dev);

	return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET_MORPHS));

}



static ssize_t

set_avoid_reset_quirk(struct device *dev, struct device_attribute *attr,

		const char *buf, size_t count)

{

	struct usb_device	*udev = to_usb_device(dev);

	int			config;



	if (sscanf(buf, "%d", &config) != 1 || config < 0 || config > 1)

		return -EINVAL;

	usb_lock_device(udev);

	if (config)

		udev->quirks |= USB_QUIRK_RESET_MORPHS;

	else

		udev->quirks &= ~USB_QUIRK_RESET_MORPHS;

	usb_unlock_device(udev);

	return count;

}



static DEVICE_ATTR(avoid_reset_quirk, S_IRUGO | S_IWUSR,

		show_avoid_reset_quirk, set_avoid_reset_quirk);



static ssize_t

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

{
@@ -558,6 +588,7 @@ static struct attribute *dev_attrs[] = { 
	&dev_attr_version.attr,

	&dev_attr_maxchild.attr,

	&dev_attr_quirks.attr,

	&dev_attr_avoid_reset_quirk.attr,

	&dev_attr_authorized.attr,

	&dev_attr_remove.attr,

	NULL,

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