Prevent a process from entering iwn_ioctl while another process is

tsleep'ing (for example waiting for the firmware to become alive)
in iwn_init.

I believe this might fix a crash reported by dhill@
This is a temporary fix until I find something better that I will
apply to my other drivers that can tsleep in if_init (wpi, run etc...)

2 files changed, 12 insertions, 2 deletions

diff --git a/sys/dev/pci/if_iwn.c b/sys/dev/pci/if_iwn.c
index d539fdae379..cc5a31635e1 100644
--- a/sys/dev/pci/if_iwn.c
+++ b/sys/dev/pci/if_iwn.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_iwn.c,v 1.93 2010/05/05 19:41:57 damien Exp $	*/
+/*	$OpenBSD: if_iwn.c,v 1.94 2010/05/05 19:47:43 damien Exp $	*/
 
 /*-
  * Copyright (c) 2007-2010 Damien Bergamini <damien.bergamini@free.fr>
@@ -3068,6 +3068,13 @@ iwn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	int s, error = 0;
 
 	s = splnet();
+	/*
+	 * Prevent processes from entering this function while another
+	 * process is tsleep'ing in it.
+	 */
+	if (sc->sc_flags & IWN_FLAG_BUSY)
+		return EBUSY;
+	sc->sc_flags |= IWN_FLAG_BUSY;
 
 	switch (cmd) {
 	case SIOCSIFADDR:
@@ -3127,6 +3134,8 @@ iwn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 			error = iwn_init(ifp);
 		}
 	}
+
+	sc->sc_flags &= ~IWN_FLAG_BUSY;
 	splx(s);
 	return error;
 }
diff --git a/sys/dev/pci/if_iwnvar.h b/sys/dev/pci/if_iwnvar.h
index 827406c2784..03e7215b5e8 100644
--- a/sys/dev/pci/if_iwnvar.h
+++ b/sys/dev/pci/if_iwnvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_iwnvar.h,v 1.18 2010/04/30 16:06:46 damien Exp $	*/
+/*	$OpenBSD: if_iwnvar.h,v 1.19 2010/05/05 19:47:43 damien Exp $	*/
 
 /*-
  * Copyright (c) 2007, 2008
@@ -207,6 +207,7 @@ struct iwn_softc {
 #define IWN_FLAG_CALIB_DONE	(1 << 2)
 #define IWN_FLAG_USE_ICT	(1 << 3)
 #define IWN_FLAG_INTERNAL_PA	(1 << 4)
+#define IWN_FLAG_BUSY		(1 << 5)
 
 	uint8_t 		hw_type;
 	const struct iwn_hal	*sc_hal;