1 files changed, 184 insertions, 0 deletions

diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index fa6f34a12b4b..1522195de715 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -21,24 +21,208 @@
 #include <linux/usb.h>
 #include "usb.h"
 
+static inline const char *plural(int n)
+{
+        return (n == 1 ? "" : "s");
+}
+
+static int choose_configuration(struct usb_device *udev)
+{
+        int i;
+        int num_configs;
+        int insufficient_power = 0;
+        struct usb_host_config *c, *best;
+
+        best = NULL;
+        c = udev->config;
+        num_configs = udev->descriptor.bNumConfigurations;
+        for (i = 0; i < num_configs; (i++, c++)) {
+                struct usb_interface_descriptor *desc = NULL;
+
+                /* It's possible that a config has no interfaces! */
+                if (c->desc.bNumInterfaces > 0)
+                        desc = &c->intf_cache[0]->altsetting->desc;
+
+                /*
+                 * HP's USB bus-powered keyboard has only one configuration
+                 * and it claims to be self-powered; other devices may have
+                 * similar errors in their descriptors.  If the next test
+                 * were allowed to execute, such configurations would always
+                 * be rejected and the devices would not work as expected.
+                 * In the meantime, we run the risk of selecting a config
+                 * that requires external power at a time when that power
+                 * isn't available.  It seems to be the lesser of two evils.
+                 *
+                 * Bugzilla #6448 reports a device that appears to crash
+                 * when it receives a GET_DEVICE_STATUS request!  We don't
+                 * have any other way to tell whether a device is self-powered,
+                 * but since we don't use that information anywhere but here,
+                 * the call has been removed.
+                 *
+                 * Maybe the GET_DEVICE_STATUS call and the test below can
+                 * be reinstated when device firmwares become more reliable.
+                 * Don't hold your breath.
+                 */
+#if 0
+                /* Rule out self-powered configs for a bus-powered device */
+                if (bus_powered && (c->desc.bmAttributes &
+                                        USB_CONFIG_ATT_SELFPOWER))
+                        continue;
+#endif
+
+                /*
+                 * The next test may not be as effective as it should be.
+                 * Some hubs have errors in their descriptor, claiming
+                 * to be self-powered when they are really bus-powered.
+                 * We will overestimate the amount of current such hubs
+                 * make available for each port.
+                 *
+                 * This is a fairly benign sort of failure.  It won't
+                 * cause us to reject configurations that we should have
+                 * accepted.
+                 */
+
+                /* Rule out configs that draw too much bus current */
+                if (c->desc.bMaxPower * 2 > udev->bus_mA) {
+                        insufficient_power++;
+                        continue;
+                }
+
+                /* If the first config's first interface is COMM/2/0xff
+                 * (MSFT RNDIS), rule it out unless Linux has host-side
+                 * RNDIS support. */
+                if (i == 0 && desc
+                                && desc->bInterfaceClass == USB_CLASS_COMM
+                                && desc->bInterfaceSubClass == 2
+                                && desc->bInterfaceProtocol == 0xff) {
+#ifndef CONFIG_USB_NET_RNDIS_HOST
+                        continue;
+#else
+                        best = c;
+#endif
+                }
+
+                /* From the remaining configs, choose the first one whose
+                 * first interface is for a non-vendor-specific class.
+                 * Reason: Linux is more likely to have a class driver
+                 * than a vendor-specific driver. */
+                else if (udev->descriptor.bDeviceClass !=
+                                                USB_CLASS_VENDOR_SPEC &&
+                                (!desc || desc->bInterfaceClass !=
+                                                USB_CLASS_VENDOR_SPEC)) {
+                        best = c;
+                        break;
+                }
+
+                /* If all the remaining configs are vendor-specific,
+                 * choose the first one. */
+                else if (!best)
+                        best = c;
+        }
+
+        if (insufficient_power > 0)
+                dev_info(&udev->dev, "rejected %d configuration%s "
+                        "due to insufficient available bus power\n",
+                        insufficient_power, plural(insufficient_power));
+
+        if (best) {
+                i = best->desc.bConfigurationValue;
+                dev_info(&udev->dev,
+                        "configuration #%d chosen from %d choice%s\n",
+                        i, num_configs, plural(num_configs));
+        } else {
+                i = -1;
+                dev_warn(&udev->dev,
+                        "no configuration chosen from %d choice%s\n",
+                        num_configs, plural(num_configs));
+        }
+        return i;
+}
+
 static int generic_probe(struct usb_device *udev)
 {
+        int err, c;
+
+        /* put device-specific files into sysfs */
+        usb_create_sysfs_dev_files(udev);
+
+        /* Choose and set the configuration.  This registers the interfaces
+         * with the driver core and lets interface drivers bind to them.
+         */
+        c = choose_configuration(udev);
+        if (c >= 0) {
+                err = usb_set_configuration(udev, c);
+                if (err) {
+                        dev_err(&udev->dev, "can't set config #%d, error %d\n",
+                                        c, err);
+                        /* This need not be fatal.  The user can try to
+                         * set other configurations. */
+                }
+        }
+
+        /* USB device state == configured ... usable */
+        usb_notify_add_device(udev);
+
         return 0;
 }
+
 static void generic_disconnect(struct usb_device *udev)
 {
+        usb_notify_remove_device(udev);
+
         /* if this is only an unbind, not a physical disconnect, then
          * unconfigure the device */
         if (udev->state == USB_STATE_CONFIGURED)
                 usb_set_configuration(udev, 0);
 
+        usb_remove_sysfs_dev_files(udev);
+
         /* in case the call failed or the device was suspended */
         if (udev->state >= USB_STATE_CONFIGURED)
                 usb_disable_device(udev, 0);
 }
 
+#ifdef  CONFIG_PM
+
+static int verify_suspended(struct device *dev, void *unused)
+{
+        if (dev->driver == NULL)
+                return 0;
+        return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0;
+}
+
+static int generic_suspend(struct usb_device *udev, pm_message_t msg)
+{
+        int     status;
+
+        /* rule out bogus requests through sysfs */
+        status = device_for_each_child(&udev->dev, NULL, verify_suspended);
+        if (status)
+                return status;
+
+        /* USB devices enter SUSPEND state through their hubs, but can be
+         * marked for FREEZE as soon as their children are already idled.
+         * But those semantics are useless, so we equate the two (sigh).
+         */
+        return usb_port_suspend(udev);
+}
+
+static int generic_resume(struct usb_device *udev)
+{
+        if (udev->state == USB_STATE_NOTATTACHED)
+                return 0;
+
+        return usb_port_resume(udev);
+}
+
+#endif  /* CONFIG_PM */
+
 struct usb_device_driver usb_generic_driver = {
         .name = "usb",
         .probe = generic_probe,
         .disconnect = generic_disconnect,
+#ifdef  CONFIG_PM
+        .suspend = generic_suspend,
+        .resume = generic_resume,
+#endif
 };