HID: minimal autosuspend support for USB HID devices

Autosuspend for USB HID devices remains problematic as far as mice
and keyboards are concerned. While I am working on a grand solution,
here's a minimalist patch that works for those devices not continously
in use.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 0a1f2b52a12fa4bab847f905e8f5069e87cb5944..a34e0f098f63e90d78a2a442601ae2793b464999 100644 (file)
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -512,7 +512,16 @@ static int hid_get_class_descriptor(struct usb_device *dev, int ifnum,
 
 int usbhid_open(struct hid_device *hid)
 {
-       ++hid->open;
+       struct usbhid_device *usbhid = hid->driver_data;
+       int res;
+
+       if (!hid->open++) {
+               res = usb_autopm_get_interface(usbhid->intf);
+               if (res < 0) {
+                       hid->open--;
+                       return -EIO;
+               }
+       }
        if (hid_start_in(hid))
                hid_io_error(hid);
        return 0;
@@ -522,8 +531,10 @@ void usbhid_close(struct hid_device *hid)
 {
        struct usbhid_device *usbhid = hid->driver_data;
 
-       if (!--hid->open)
+       if (!--hid->open) {
                usb_kill_urb(usbhid->urbin);
+               usb_autopm_put_interface(usbhid->intf);
+       }
 }
 
 /*
@@ -1048,6 +1059,7 @@ static struct usb_driver hid_driver = {
        .pre_reset =    hid_pre_reset,
        .post_reset =   hid_post_reset,
        .id_table =     hid_usb_ids,
+       .supports_autosuspend = 1,
 };
 
 static int __init hid_init(void)