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authorOliver Neukum <oliver@neukum.org>2010-01-16 01:33:03 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-03-02 14:53:23 -0800
commitef955341f692475236f0fbe6853f49337dff77a5 (patch)
tree782c8677ba375ada558578fefe5321c84c5b4dff
parent5d3987796c7a747e5ed3ded1eb64a9632d52a1a4 (diff)
downloadlinux-ef955341f692475236f0fbe6853f49337dff77a5.tar.bz2
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>
-rw-r--r--Documentation/ABI/testing/sysfs-bus-usb11
-rw-r--r--drivers/usb/core/sysfs.c31
2 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index a07c0f366f91..a986e9bbba3d 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -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
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 5f3908f6e2dc..b1725abf6c7b 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -191,6 +191,36 @@ 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)
{
struct usb_device *udev;
@@ -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,