Re: Panic with ugen

From: Jay Cornwall <jay_at_evilrealms.net>
Date: Thu, 27 Nov 2003 14:24:53 +0000
Martin wrote:

> panic()
> destroy_dev()
> ugen_destroy_devnodes()
> ugen_set_config()

Could you try the attached patch, to see if it fixes the panic on the second 
run of your program?

-- 
Cheers,
Jay

http://www.evilrealms.net/ - Systems Administrator & Developer
http://www.imperial.ac.uk/ - 3rd year CS student

Index: sys/dev/usb/ugen.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/ugen.c,v
retrieving revision 1.81
diff -u -3 -p -r1.81 ugen.c
--- sys/dev/usb/ugen.c	9 Nov 2003 09:17:22 -0000	1.81
+++ sys/dev/usb/ugen.c	27 Nov 2003 14:06:25 -0000
_at__at_ -1014,8 +1014,8 _at__at_ ugen_set_interface(struct ugen_softc *sc
 	usbd_interface_handle iface;
 	usb_endpoint_descriptor_t *ed;
 	usbd_status err;
-	struct ugen_endpoint *sce;
-	u_int8_t niface, nendpt, endptno, endpt;
+	struct ugen_endpoint *sce, **sce_cache;
+	u_int8_t niface, nendpt, nendpt_cache, endptno, endpt;
 	int dir;
 
 	DPRINTFN(15, ("ugen_set_interface %d %d\n", ifaceidx, altno));
_at__at_ -1033,30 +1033,47 _at__at_ ugen_set_interface(struct ugen_softc *sc
 	if (err)
 		return (err);
 
-#if defined(__FreeBSD__)
-	/* destroy the existing devices, we remake the new ones in a moment */
-	ugen_destroy_devnodes(sc);
-#endif
+	/* store an array of endpoint descriptors to destroy if the interface
+	 * change succeeds - these aren't available afterwards */
+	sce_cache = malloc(sizeof(struct ugen_endpoint *) * nendpt, M_TEMP,
+		M_WAITOK);
+	nendpt_cache = nendpt;
 
-	/* XXX should only do this after setting new altno has succeeded */
 	for (endptno = 0; endptno < nendpt; endptno++) {
 		ed = usbd_interface2endpoint_descriptor(iface,endptno);
 		endpt = ed->bEndpointAddress;
 		dir = UE_GET_DIR(endpt) == UE_DIR_IN ? IN : OUT;
-		sce = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
-		sce->sc = 0;
-		sce->edesc = 0;
-		sce->iface = 0;
+		sce_cache[endptno] = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
 	}
 
 	/* change setting */
 	err = usbd_set_interface(iface, altno);
-	if (err)
+	if (err) {
+		free(sce_cache, M_TEMP);
 		return (err);
+	}
 
 	err = usbd_endpoint_count(iface, &nendpt);
-	if (err)
+	if (err) {
+		free(sce_cache, M_TEMP);
 		return (err);
+	}
+
+#if defined(__FreeBSD__)
+	/* destroy the existing devices, we remake the new ones in a moment */
+	ugen_destroy_devnodes(sc);
+#endif
+
+	/* now we can clear the old interface's ugen_endpoints */
+	for (endptno = 0; endptno < nendpt_cache; endptno++) {
+		sce = sce_cache[endptno];
+		sce->sc = 0;
+		sce->edesc = 0;
+		sce->iface = 0;
+	}
+	free(sce_cache, M_TEMP);
+
+	/* set the new interface's ugen_endpoints */
 	for (endptno = 0; endptno < nendpt; endptno++) {
 		ed = usbd_interface2endpoint_descriptor(iface,endptno);
 		endpt = ed->bEndpointAddress;
Received on Thu Nov 27 2003 - 05:24:57 UTC

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