From ef955341f692475236f0fbe6853f49337dff77a5 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Sat, 16 Jan 2010 01:33:03 +0100 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-bus-usb | 11 +++++++++ drivers/usb/core/sysfs.c | 31 +++++++++++++++++++++++++ 2 files changed, 42 insertions(+) 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 +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 @@ -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, -- 2.20.1