Bluetooth: Make hidp_get_raw_report abort if the session is terminating

After linux 3.2 the hid_destroy_device call in hidp_session
cleaning up invokes a hook to the power_supply code which
in turn tries to read the battery capacity. This read will
trigger a call to hidp_get_raw_report which is bound to fail
because the device is being taken away - so rather than
wait for the 5 second timeout failure this changes enables
it to fail straight away.
Signed-off-by: Karl Relton <karllinuxtest.relton@ntlworld.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/hidp/core.c

@@ -311,6 +311,9 @@ static int hidp_get_raw_report(struct hid_device *hid,
 	int numbered_reports = hid->report_enum[report_type].numbered;
 	int ret;
 
+	if (atomic_read(&session->terminate))
+		return -EIO;
+
 	switch (report_type) {
 	case HID_FEATURE_REPORT:
 		report_type = HIDP_TRANS_GET_REPORT | HIDP_DATA_RTYPE_FEATURE;
@@ -722,6 +725,7 @@ static int hidp_session(void *arg)
 		set_current_state(TASK_INTERRUPTIBLE);
 	}
 	set_current_state(TASK_RUNNING);
+	atomic_inc(&session->terminate);
 	remove_wait_queue(sk_sleep(intr_sk), &intr_wait);
 	remove_wait_queue(sk_sleep(ctrl_sk), &ctrl_wait);