svn commit: r261228 - head/sys/dev/usb/input

[Hans Petter Selasky]

Author: hselasky
Date: Tue Jan 28 09:55:07 2014
New Revision: 261228
URL: http://svnweb.freebsd.org/changeset/base/261228

Log:
  When detaching a [USB] keyboard, keys might still be pressed. Ensure
  that all pressed keys are released before completing the USB keyboard
  detach. This will prevent so-called "ghost-keys" from appearing after
  that the USB device generating the key event(s) has been detached.
  
  MFC after:	1 week

Modified:
  head/sys/dev/usb/input/ukbd.c

Modified: head/sys/dev/usb/input/ukbd.c
==============================================================================
--- head/sys/dev/usb/input/ukbd.c	Tue Jan 28 09:12:04 2014	(r261227)
+++ head/sys/dev/usb/input/ukbd.c	Tue Jan 28 09:55:07 2014	(r261228)
@@ -473,7 +473,8 @@ ukbd_get_key(struct ukbd_softc *sc, uint
 	    || (sc->sc_flags & UKBD_FLAG_POLLING) != 0,
 	    ("not polling in kdb or panic\n"));
 
-	if (sc->sc_inputs == 0) {
+	if (sc->sc_inputs == 0 &&
+	    (sc->sc_flags & UKBD_FLAG_GONE) == 0) {
 		/* start transfer, if not already started */
 		usbd_transfer_start(sc->sc_xfer[UKBD_INTR_DT]);
 	}
@@ -1319,6 +1320,18 @@ ukbd_detach(device_t dev)
 
 	usb_callout_stop(&sc->sc_callout);
 
+	/* kill any stuck keys */
+	if (sc->sc_flags & UKBD_FLAG_ATTACHED) {
+		/* stop receiving events from the USB keyboard */
+		usbd_transfer_stop(sc->sc_xfer[UKBD_INTR_DT]);
+
+		/* release all leftover keys, if any */
+		memset(&sc->sc_ndata, 0, sizeof(sc->sc_ndata));
+
+		/* process releasing of all keys */
+		ukbd_interrupt(sc);
+	}
+
 	ukbd_disable(&sc->sc_kbd);
 
 #ifdef KBD_INSTALL_CDEV