From 7bf442ed4e000a4c0cfe767af868f9aa8242892f Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Thu, 14 Feb 2008 12:53:52 +0000
Subject: [PATCH] Release serializer around firmware_load_image() to avoid
 possible dead lock.  Add comment about it.

---
 sys/dev/netif/acx/if_acx.c | 30 +++++++++++++++++++++++-------
 sys/dev/netif/bwi/bwimac.c | 33 ++++++++++++++++++++++++++++-----
 2 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/sys/dev/netif/acx/if_acx.c b/sys/dev/netif/acx/if_acx.c
index e0c7fd075..c4c0a6f3c 100644
--- a/sys/dev/netif/acx/if_acx.c
+++ b/sys/dev/netif/acx/if_acx.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/dev/netif/acx/if_acx.c,v 1.25 2008/02/06 08:21:22 sephe Exp $
+ * $DragonFly: src/sys/dev/netif/acx/if_acx.c,v 1.26 2008/02/14 12:53:52 sephe Exp $
  */
 
 /*
@@ -1669,9 +1669,17 @@ static int
 acx_alloc_firmware(struct acx_softc *sc)
 {
 	struct acx_firmware *fw = &sc->sc_firmware;
+	struct ifnet *ifp = &sc->sc_ic.ic_if;
+	struct fw_image *img;
 	char filename[64];
 	int error = 0;
 
+	/*
+	 * NB: serializer need to be released before loading firmware
+	 *     image to avoid possible dead lock
+	 */
+	ASSERT_SERIALIZED(ifp->if_serializer);
+
 	if (fw->base_fw_image == NULL) {
 		if (fw->combined_radio_fw) {
 			ksnprintf(filename, sizeof(filename),
@@ -1681,10 +1689,14 @@ acx_alloc_firmware(struct acx_softc *sc)
 			ksnprintf(filename, sizeof(filename),
 				  ACX_BASE_FW_PATH, fw->fwdir);
 		}
-		fw->base_fw_image = firmware_image_load(filename, NULL);
+
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(filename, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		fw->base_fw_image = img;
 		if (fw->base_fw_image == NULL) {
-			if_printf(&sc->sc_ic.ic_if, "load %s base fw failed\n",
-				  filename);
+			if_printf(ifp, "load %s base fw failed\n", filename);
 			error = EIO;
 			goto back;
 		}
@@ -1698,10 +1710,14 @@ acx_alloc_firmware(struct acx_softc *sc)
 	if (!fw->combined_radio_fw && fw->radio_fw_image == NULL) {
 		ksnprintf(filename, sizeof(filename), ACX_RADIO_FW_PATH,
 			  fw->fwdir, sc->sc_radio_type);
-		fw->radio_fw_image = firmware_image_load(filename, NULL);
+
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(filename, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		fw->radio_fw_image = img;
 		if (fw->radio_fw_image == NULL) {
-			if_printf(&sc->sc_ic.ic_if, "load %s radio fw failed\n",
-				  filename);
+			if_printf(ifp, "load %s radio fw failed\n", filename);
 			error = EIO;
 			goto back;
 		}
diff --git a/sys/dev/netif/bwi/bwimac.c b/sys/dev/netif/bwi/bwimac.c
index 786635892..04b87a28f 100644
--- a/sys/dev/netif/bwi/bwimac.c
+++ b/sys/dev/netif/bwi/bwimac.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/dev/netif/bwi/bwimac.c,v 1.11 2008/01/15 09:01:13 sephe Exp $
+ * $DragonFly: src/sys/dev/netif/bwi/bwimac.c,v 1.12 2008/02/14 12:53:51 sephe Exp $
  */
 
 #include <sys/param.h>
@@ -870,15 +870,26 @@ bwi_mac_fw_alloc(struct bwi_mac *mac)
 {
 	struct bwi_softc *sc = mac->mac_sc;
 	struct ifnet *ifp = &sc->sc_ic.ic_if;
+	struct fw_image *img;
 	char fwname[64];
 	int idx;
 
+	/*
+	 * NB: serializer need to be released before loading firmware
+	 *     image to avoid possible dead lock
+	 */
+	ASSERT_SERIALIZED(ifp->if_serializer);
+
 	if (mac->mac_ucode == NULL) {
 		ksnprintf(fwname, sizeof(fwname), BWI_FW_UCODE_PATH,
 			  sc->sc_fw_version,
 			  mac->mac_rev >= 5 ? 5 : mac->mac_rev);
 
-		mac->mac_ucode = firmware_image_load(fwname, NULL);
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(fwname, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		mac->mac_ucode = img;
 		if (mac->mac_ucode == NULL) {
 			if_printf(ifp, "request firmware %s failed\n", fwname);
 			return ENOMEM;
@@ -893,7 +904,11 @@ bwi_mac_fw_alloc(struct bwi_mac *mac)
 			  sc->sc_fw_version,
 			  mac->mac_rev < 5 ? 4 : 5);
 
-		mac->mac_pcm = firmware_image_load(fwname, NULL);
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(fwname, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		mac->mac_pcm = img;
 		if (mac->mac_pcm == NULL) {
 			if_printf(ifp, "request firmware %s failed\n", fwname);
 			return ENOMEM;
@@ -918,7 +933,11 @@ bwi_mac_fw_alloc(struct bwi_mac *mac)
 		ksnprintf(fwname, sizeof(fwname), BWI_FW_IV_PATH,
 			  sc->sc_fw_version, idx);
 
-		mac->mac_iv = firmware_image_load(fwname, NULL);
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(fwname, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		mac->mac_iv = img;
 		if (mac->mac_iv == NULL) {
 			if_printf(ifp, "request firmware %s failed\n", fwname);
 			return ENOMEM;
@@ -944,7 +963,11 @@ bwi_mac_fw_alloc(struct bwi_mac *mac)
 		ksnprintf(fwname, sizeof(fwname), BWI_FW_IV_EXT_PATH,
 			  sc->sc_fw_version, idx);
 
-		mac->mac_iv_ext = firmware_image_load(fwname, NULL);
+		lwkt_serialize_exit(ifp->if_serializer);
+		img = firmware_image_load(fwname, NULL);
+		lwkt_serialize_enter(ifp->if_serializer);
+
+		mac->mac_iv_ext = img;
 		if (mac->mac_iv_ext == NULL) {
 			if_printf(ifp, "request firmware %s failed\n", fwname);
 			return ENOMEM;
-- 
2.11.4.GIT