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>

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 0a1f2b52a12f..a34e0f098f63 100644
--- 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)