Re: kern/52553: Panic on "ifconfig athn0 up"

[Nick Hudson <skrll%netbsd.org@localhost>]

On 09/18/17 17:05, Andreas Gustafsson wrote:
>    while true; do ifconfig athn0 down; ifconfig athn0 up; done

Please try this patch...

Nick

Index: sys/dev/usb/if_athn_usb.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/if_athn_usb.c,v
retrieving revision 1.22
diff -u -p -r1.22 if_athn_usb.c
--- sys/dev/usb/if_athn_usb.c	1 Jun 2017 02:45:11 -0000	1.22
+++ sys/dev/usb/if_athn_usb.c	21 Sep 2017 19:42:29 -0000
@@ -728,9 +728,15 @@ athn_usb_alloc_tx_list(struct athn_usb_s
 		/* Append this Tx buffer to our free list. */
 		TAILQ_INSERT_TAIL(&usc->usc_tx_free_list, data, next);
 	}
-	if (error != 0)
+	if (error == 0) {
+		/* Steal one buffer for beacons. */
+		usc->usc_tx_bcn = TAILQ_FIRST(&usc->usc_tx_free_list);
+		TAILQ_REMOVE(&usc->usc_tx_free_list, usc->usc_tx_bcn, next);
+	} else {
 		athn_usb_free_tx_list(usc);
+	}
 	mutex_exit(&usc->usc_tx_mtx);
+
 	return error;
 }
 
@@ -749,6 +755,8 @@ athn_usb_free_tx_list(struct athn_usb_so
 		if (xfer != NULL)
 			usbd_destroy_xfer(xfer);
 	}
+	if (usc->usc_tx_bcn)
+		usbd_destroy_xfer(usc->usc_tx_bcn->xfer);
 }
 
 Static int
@@ -2756,12 +2764,6 @@ athn_usb_init_locked(struct ifnet *ifp)
 	usc->usc_cmdq.cur = usc->usc_cmdq.next = usc->usc_cmdq.queued = 0;
 	mutex_spin_exit(&usc->usc_task_mtx);
 
-	/* Steal one buffer for beacons. */
-	mutex_enter(&usc->usc_tx_mtx);
-	usc->usc_tx_bcn = TAILQ_FIRST(&usc->usc_tx_free_list);
-	TAILQ_REMOVE(&usc->usc_tx_free_list, usc->usc_tx_bcn, next);
-	mutex_exit(&usc->usc_tx_mtx);
-
 	curchan = ic->ic_curchan;
 	extchan = NULL;