PERFORCE change 36743 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=36743

Change 36743 by marcel at marcel_nfs on 2003/08/23 00:17:44

	Only allocate a new softc if the derived softc is larger
	than the generic (base) softc. Why do all the work if the
	end result is the same.
	While on the subject, set the softc to NULL on detach and
	make sure we free the softc if we allocated one. I expect
	that reattachment is preceeded by probing and that the bus
	layer will allocate a new softc (especially since there
	isn't one after detach now).

Affected files ...

.. //depot/projects/uart/dev/uart/uart_core.c#21 edit

Differences ...

==== //depot/projects/uart/dev/uart/uart_core.c#21 (text+ko) ====

@@ -439,9 +439,12 @@
 	 * the device.
 	 */
 	sc0 = device_get_softc(dev);
-	sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
-	bcopy(sc0, sc, sizeof(*sc));
-	device_set_softc(dev, sc);
+	if (sc0->sc_class->size > sizeof(*sc)) {
+		sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
+		bcopy(sc0, sc, sizeof(*sc));
+		device_set_softc(dev, sc);
+	} else
+		sc = sc0;
 
 	/*
 	 * Protect ourselves against interrupts while we're not completely
@@ -591,6 +594,12 @@
 	}
 	bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
 
+	if (sc->sc_class->size > sizeof(*sc)) {
+		device_set_softc(dev, NULL);
+		free(sc, M_UART);
+	} else
+		device_set_softc(dev, NULL);
+
 	return (0);
 }