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: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2010-01-16 01:33:03 +01:00 committed by Greg Kroah-Hartman
parent 5d3987796c
commit ef955341f6
2 changed files with 42 additions and 0 deletions

View File

@ -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

View File

@ -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,