Slightly tune locking to not call xpt_alloc_ccb() that is allowed to sleep

while holding the SIM mutex.

2 files changed, 4 insertions, 7 deletions

diff --git a/sys/dev/tws/tws_cam.c b/sys/dev/tws/tws_cam.c
index 657777a..d988349 100644
--- a/sys/dev/tws/tws_cam.c
+++ b/sys/dev/tws/tws_cam.c
@@ -217,17 +217,16 @@ tws_bus_scan(struct tws_softc *sc)
     TWS_TRACE_DEBUG(sc, "entry", sc, 0);
     if (!(sc->sim))
         return(ENXIO);
-    mtx_assert(&sc->sim_lock, MA_OWNED);
-    if ((ccb = xpt_alloc_ccb()) == NULL)
-		    return(ENOMEM);
-
+    ccb = xpt_alloc_ccb();
+    mtx_lock(&sc->sim_lock);
     if (xpt_create_path(&ccb->ccb_h.path, xpt_periph, cam_sim_path(sc->sim),
                   CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
+	mtx_unlock(&sc->sim_lock);
         xpt_free_ccb(ccb);
         return(EIO);
     }
     xpt_rescan(ccb);
-    
+    mtx_unlock(&sc->sim_lock);
     return(0);
 }
 
diff --git a/sys/dev/tws/tws_user.c b/sys/dev/tws/tws_user.c
index cbd03c9..223cc07 100644
--- a/sys/dev/tws/tws_user.c
+++ b/sys/dev/tws/tws_user.c
@@ -73,9 +73,7 @@ tws_ioctl(struct cdev *dev, u_long cmd, caddr_t buf, int flags,
             break;
         case TWS_IOCTL_SCAN_BUS :
             TWS_TRACE_DEBUG(sc, "scan-bus", 0, 0);
-            mtx_lock(&sc->sim_lock);
             error = tws_bus_scan(sc);
-            mtx_unlock(&sc->sim_lock);
             break;
         default :
             TWS_TRACE_DEBUG(sc, "ioctl-aen", cmd, buf);