usb: Use hub port data to determine whether a port is removable

Hubs have a flag to indicate whether a given port carries removable devices
or not. This is not strictly accurate in that some built-in devices
will be flagged as removable, but followup patches will make use of platform
data to make this more reliable.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a0613d8f9be7..2d773cbe191c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1838,6 +1838,37 @@ fail:
         return err;
 }
 
+static void set_usb_port_removable(struct usb_device *udev)
+{
+        struct usb_device *hdev = udev->parent;
+        struct usb_hub *hub;
+        u8 port = udev->portnum;
+        u16 wHubCharacteristics;
+        bool removable = true;
+
+        if (!hdev)
+                return;
+
+        hub = hdev_to_hub(udev->parent);
+
+        wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
+
+        if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
+                return;
+
+        if (hub_is_superspeed(hdev)) {
+                if (hub->descriptor->u.ss.DeviceRemovable & (1 << port))
+                        removable = false;
+        } else {
+                if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
+                        removable = false;
+        }
+
+        if (removable)
+                udev->removable = USB_DEVICE_REMOVABLE;
+        else
+                udev->removable = USB_DEVICE_FIXED;
+}
 
 /**
  * usb_new_device - perform initial device setup (usbcore-internal)
@@ -1896,6 +1927,15 @@ int usb_new_device(struct usb_device *udev)
         announce_device(udev);
 
         device_enable_async_suspend(&udev->dev);
+
+        /*
+         * check whether the hub marks this port as non-removable. Do it
+         * now so that platform-specific data can override it in
+         * device_add()
+         */
+        if (udev->parent)
+                set_usb_port_removable(udev);
+
         /* Register the device.  The device driver is responsible
          * for configuring the device and invoking the add-device
          * notifier chain (used by usbfs and possibly others).