From 694d02aab2058ebbae5e44eb00c3af2fa6482988 Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <riastradh@NetBSD.org>
Date: Tue, 7 Apr 2020 02:50:26 +0000
Subject: [PATCH] Fix uhidev detach.

- Omit needless sc_dying.
- Omit needless uhidev_activate.
- Use config_detach_children.
- Don't free anything or take any other destructive actions until
  after config_detach_children has succeeded.
- Move rnd_detach_source into uhidev_childdet where it belongs.
---
 sys/dev/usb/uhidev.c | 45 +++++++++++---------------------------------
 sys/dev/usb/uhidev.h |  1 -
 2 files changed, 11 insertions(+), 35 deletions(-)

diff --git a/sys/dev/usb/uhidev.c b/sys/dev/usb/uhidev.c
index e29616c01f79..8f4679f53f48 100644
--- a/sys/dev/usb/uhidev.c
+++ b/sys/dev/usb/uhidev.c
@@ -89,10 +89,9 @@ static int uhidev_match(device_t, cfdata_t, void *);
 static void uhidev_attach(device_t, device_t, void *);
 static void uhidev_childdet(device_t, device_t);
 static int uhidev_detach(device_t, int);
-static int uhidev_activate(device_t, enum devact);
 
 CFATTACH_DECL2_NEW(uhidev, sizeof(struct uhidev_softc), uhidev_match,
-    uhidev_attach, uhidev_detach, uhidev_activate, NULL, uhidev_childdet);
+    uhidev_attach, uhidev_detach, NULL, NULL, uhidev_childdet);
 
 static int
 uhidev_match(device_t parent, cfdata_t match, void *aux)
@@ -173,7 +172,6 @@ uhidev_attach(device_t parent, device_t self, void *aux)
 		if (ed == NULL) {
 			aprint_error_dev(self,
 			    "could not read endpoint descriptor\n");
-			sc->sc_dying = 1;
 			return;
 		}
 
@@ -204,7 +202,6 @@ uhidev_attach(device_t parent, device_t self, void *aux)
 	 */
 	if (sc->sc_iep_addr == -1) {
 		aprint_error_dev(self, "no input interrupt endpoint\n");
-		sc->sc_dying = 1;
 		return;
 	}
 
@@ -265,7 +262,6 @@ uhidev_attach(device_t parent, device_t self, void *aux)
 	}
 	if (err) {
 		aprint_error_dev(self, "no report descriptor\n");
-		sc->sc_dying = 1;
 		return;
 	}
 
@@ -413,25 +409,12 @@ uhidevprint(void *aux, const char *pnp)
 	return UNCONF;
 }
 
-static int
-uhidev_activate(device_t self, enum devact act)
-{
-	struct uhidev_softc *sc = device_private(self);
-
-	switch (act) {
-	case DVACT_DEACTIVATE:
-		sc->sc_dying = 1;
-		return 0;
-	default:
-		return EOPNOTSUPP;
-	}
-}
-
 static void
 uhidev_childdet(device_t self, device_t child)
 {
 	int i;
 	struct uhidev_softc *sc = device_private(self);
+	struct uhidev *csc = device_private(child);
 
 	for (i = 0; i < sc->sc_nrepid; i++) {
 		if (sc->sc_subdevs[i] == child)
@@ -439,39 +422,33 @@ uhidev_childdet(device_t self, device_t child)
 	}
 	KASSERT(i < sc->sc_nrepid);
 	sc->sc_subdevs[i] = NULL;
+	rnd_detach_source(&csc->rnd_source);
 }
 
 static int
 uhidev_detach(device_t self, int flags)
 {
 	struct uhidev_softc *sc = device_private(self);
-	int i, rv;
-	struct uhidev *csc;
+	int error;
 
 	DPRINTF(("uhidev_detach: sc=%p flags=%d\n", sc, flags));
 
-	sc->sc_dying = 1;
 	if (sc->sc_ipipe != NULL)
 		usbd_abort_pipe(sc->sc_ipipe);
 
-	if (sc->sc_repdesc != NULL)
-		kmem_free(sc->sc_repdesc, sc->sc_repdesc_size);
-
-	rv = 0;
-	for (i = 0; i < sc->sc_nrepid; i++) {
-		if (sc->sc_subdevs[i] != NULL) {
-			csc = device_private(sc->sc_subdevs[i]);
-			rnd_detach_source(&csc->rnd_source);
-			rv |= config_detach(sc->sc_subdevs[i], flags);
-		}
-	}
+	error = config_detach_children(self, flags);
+	if (error)
+		return error;
 
 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev, sc->sc_dev);
 
+	if (sc->sc_repdesc != NULL)
+		kmem_free(sc->sc_repdesc, sc->sc_repdesc_size);
+
 	pmf_device_deregister(self);
 	mutex_destroy(&sc->sc_lock);
 
-	return rv;
+	return 0;
 }
 
 void
diff --git a/sys/dev/usb/uhidev.h b/sys/dev/usb/uhidev.h
index 66f5b5930da5..789b327d97f5 100644
--- a/sys/dev/usb/uhidev.h
+++ b/sys/dev/usb/uhidev.h
@@ -54,7 +54,6 @@ struct uhidev_softc {
 	device_t *sc_subdevs;
 
 	int sc_refcnt;
-	u_char sc_dying;
 
 	kmutex_t sc_lock;		/* protects writes to sc_state */