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authorAlan Stern <stern@rowland.harvard.edu>2006-06-01 13:33:42 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2006-06-21 15:04:15 -0700
commit79efa097e75018a2918155f343f0e08e61ee8a8c (patch)
tree336237ca96191aeb9cac6ed8706bc479545f3108 /drivers/usb/core
parentefcaa20525fde82bbb4fb8cd9e9016f6fabc6509 (diff)
[PATCH] usbcore: port reset for composite devices
This patch (as699) adds usb_reset_composite_device(), a routine for sending a USB port reset to a device with multiple interfaces owned by different drivers. Drivers are notified about impending and completed resets through two new methods in the usb_driver structure. The patch modifieds the usbfs ioctl code to make it use the new routine instead of usb_reset_device(). Follow-up patches will modify the hub, usb-storage, and usbhid drivers so they can utilize this new API. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/devio.c3
-rw-r--r--drivers/usb/core/hub.c84
-rw-r--r--drivers/usb/core/usb.c1
3 files changed, 83 insertions, 5 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index b04ede772f2c..df3fb57d71e6 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -823,8 +823,7 @@ static int proc_connectinfo(struct dev_state *ps, void __user *arg)
static int proc_resetdevice(struct dev_state *ps)
{
- return usb_reset_device(ps->dev);
-
+ return usb_reset_composite_device(ps->dev, NULL);
}
static int proc_setintf(struct dev_state *ps, void __user *arg)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f41c08946a52..37c67d7e8b84 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3007,9 +3007,9 @@ static int config_descriptors_changed(struct usb_device *udev)
* usb_reset_device - perform a USB port reset to reinitialize a device
* @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
*
- * WARNING - don't reset any device unless drivers for all of its
- * interfaces are expecting that reset! Maybe some driver->reset()
- * method should eventually help ensure sufficient cooperation.
+ * WARNING - don't use this routine to reset a composite device
+ * (one with multiple interfaces owned by separate drivers)!
+ * Use usb_reset_composite_device() instead.
*
* Do a port reset, reassign the device's address, and establish its
* former operating configuration. If the reset fails, or the device's
@@ -3125,3 +3125,81 @@ re_enumerate:
hub_port_logical_disconnect(parent_hub, port1);
return -ENODEV;
}
+
+/**
+ * usb_reset_composite_device - warn interface drivers and perform a USB port reset
+ * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
+ * @iface: interface bound to the driver making the request (optional)
+ *
+ * Warns all drivers bound to registered interfaces (using their pre_reset
+ * method), performs the port reset, and then lets the drivers know that
+ * the reset is over (using their post_reset method).
+ *
+ * Return value is the same as for usb_reset_device().
+ *
+ * The caller must own the device lock. For example, it's safe to use
+ * this from a driver probe() routine after downloading new firmware.
+ * For calls that might not occur during probe(), drivers should lock
+ * the device using usb_lock_device_for_reset().
+ *
+ * The interface locks are acquired during the pre_reset stage and released
+ * during the post_reset stage. However if iface is not NULL and is
+ * currently being probed, we assume that the caller already owns its
+ * lock.
+ */
+int usb_reset_composite_device(struct usb_device *udev,
+ struct usb_interface *iface)
+{
+ int ret;
+ struct usb_host_config *config = udev->actconfig;
+
+ if (udev->state == USB_STATE_NOTATTACHED ||
+ udev->state == USB_STATE_SUSPENDED) {
+ dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
+ udev->state);
+ return -EINVAL;
+ }
+
+ if (iface && iface->condition != USB_INTERFACE_BINDING)
+ iface = NULL;
+
+ if (config) {
+ int i;
+ struct usb_interface *cintf;
+ struct usb_driver *drv;
+
+ for (i = 0; i < config->desc.bNumInterfaces; ++i) {
+ cintf = config->interface[i];
+ if (cintf != iface)
+ down(&cintf->dev.sem);
+ if (device_is_registered(&cintf->dev) &&
+ cintf->dev.driver) {
+ drv = to_usb_driver(cintf->dev.driver);
+ if (drv->pre_reset)
+ (drv->pre_reset)(cintf);
+ }
+ }
+ }
+
+ ret = usb_reset_device(udev);
+
+ if (config) {
+ int i;
+ struct usb_interface *cintf;
+ struct usb_driver *drv;
+
+ for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
+ cintf = config->interface[i];
+ if (device_is_registered(&cintf->dev) &&
+ cintf->dev.driver) {
+ drv = to_usb_driver(cintf->dev.driver);
+ if (drv->post_reset)
+ (drv->post_reset)(cintf);
+ }
+ if (cintf != iface)
+ up(&cintf->dev.sem);
+ }
+ }
+
+ return ret;
+}
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index b7fdc1cd134a..515310751303 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -1207,6 +1207,7 @@ EXPORT_SYMBOL(usb_ifnum_to_if);
EXPORT_SYMBOL(usb_altnum_to_altsetting);
EXPORT_SYMBOL(usb_reset_device);
+EXPORT_SYMBOL(usb_reset_composite_device);
EXPORT_SYMBOL(__usb_get_extra_descriptor);