5 files changed, 48 insertions, 16 deletions

diff --git a/sys/dev/usb2/controller/usb2_bus.h b/sys/dev/usb2/controller/usb2_bus.h
index 43776fdda7ad..c81a7a5b9174 100644
--- a/sys/dev/usb2/controller/usb2_bus.h
+++ b/sys/dev/usb2/controller/usb2_bus.h
@@ -53,6 +53,13 @@ struct usb2_bus {
 	struct usb2_bus_stat stats_ok;
 	struct usb2_process explore_proc;
 	struct usb2_process roothub_proc;
+	/*
+	 * There are two callback processes. One for Giant locked
+	 * callbacks. One for non-Giant locked callbacks. This should
+	 * avoid congestion and reduce response time in most cases.
+	 */
+	struct usb2_process giant_callback_proc;
+	struct usb2_process non_giant_callback_proc;
 	struct usb2_bus_msg explore_msg[2];
 	struct usb2_bus_msg detach_msg[2];
 	struct usb2_bus_msg attach_msg[2];
diff --git a/sys/dev/usb2/controller/usb2_controller.c b/sys/dev/usb2/controller/usb2_controller.c
index 61ce31482d1b..a9596c76d9ac 100644
--- a/sys/dev/usb2/controller/usb2_controller.c
+++ b/sys/dev/usb2/controller/usb2_controller.c
@@ -166,6 +166,11 @@ usb2_detach(device_t dev)
 
 	USB_BUS_UNLOCK(bus);
 
+	/* Get rid of USB callback processes */
+
+	usb2_proc_unsetup(&bus->giant_callback_proc);
+	usb2_proc_unsetup(&bus->non_giant_callback_proc);
+
 	/* Get rid of USB roothub process */
 
 	usb2_proc_unsetup(&bus->roothub_proc);
@@ -391,8 +396,17 @@ usb2_attach_sub(device_t dev, struct usb2_bus *bus)
 	bus->roothub_msg[1].hdr.pm_callback = &usb2_bus_roothub;
 	bus->roothub_msg[1].bus = bus;
 
-	/* Create USB explore and roothub processes */
-	if (usb2_proc_setup(&bus->roothub_proc,
+	/* Create USB explore, roothub and callback processes */
+
+	if (usb2_proc_setup(&bus->giant_callback_proc,
+	    &bus->bus_mtx, USB_PRI_MED)) {
+		printf("WARNING: Creation of USB Giant "
+		    "callback process failed.\n");
+	} else if (usb2_proc_setup(&bus->non_giant_callback_proc,
+	    &bus->bus_mtx, USB_PRI_HIGH)) {
+		printf("WARNING: Creation of USB non-Giant "
+		    "callback process failed.\n");
+	} else if (usb2_proc_setup(&bus->roothub_proc,
 	    &bus->bus_mtx, USB_PRI_HIGH)) {
 		printf("WARNING: Creation of USB roothub "
 		    "process failed.\n");
diff --git a/sys/dev/usb2/core/usb2_device.c b/sys/dev/usb2/core/usb2_device.c
index b54f8633c50c..dfe5e8abf654 100644
--- a/sys/dev/usb2/core/usb2_device.c
+++ b/sys/dev/usb2/core/usb2_device.c
@@ -1742,8 +1742,18 @@ usb2_free_device(struct usb2_device *udev)
 	/* unsetup any leftover default USB transfers */
 	usb2_transfer_unsetup(udev->default_xfer, USB_DEFAULT_XFER_MAX);
 
+	/* template unsetup, if any */
 	(usb2_temp_unsetup_p) (udev);
 
+	/* 
+	 * Make sure that our clear-stall messages are not queued
+	 * anywhere:
+	 */
+	USB_BUS_LOCK(udev->bus);
+	usb2_proc_mwait(&udev->bus->non_giant_callback_proc,
+	    &udev->cs_msg[0], &udev->cs_msg[1]);
+	USB_BUS_UNLOCK(udev->bus);
+
 	sx_destroy(udev->default_sx);
 	sx_destroy(udev->default_sx + 1);
 
diff --git a/sys/dev/usb2/core/usb2_transfer.c b/sys/dev/usb2/core/usb2_transfer.c
index 2237c7ec286d..a5a3e8b0ec85 100644
--- a/sys/dev/usb2/core/usb2_transfer.c
+++ b/sys/dev/usb2/core/usb2_transfer.c
@@ -819,13 +819,12 @@ usb2_transfer_setup(struct usb2_device *udev,
 			info->done_m[1].hdr.pm_callback = &usb2_callback_proc;
 			info->done_m[1].xroot = info;
 
-			/* create a callback thread */
-
-			if (usb2_proc_setup(&info->done_p,
-			    &udev->bus->bus_mtx, USB_PRI_HIGH)) {
-				parm.err = USB_ERR_NO_INTR_THREAD;
-				goto done;
-			}
+			if (xfer_mtx == &Giant)
+				info->done_p = 
+				    &udev->bus->giant_callback_proc;
+			else
+				info->done_p = 
+				    &udev->bus->non_giant_callback_proc;
 		}
 		/* reset sizes */
 
@@ -1045,10 +1044,11 @@ usb2_transfer_unsetup_sub(struct usb2_xfer_root *info, uint8_t needs_delay)
 		temp = usb2_get_dma_delay(info->bus);
 		usb2_pause_mtx(&info->bus->bus_mtx, temp);
 	}
-	USB_BUS_UNLOCK(info->bus);
 
-	/* wait for interrupt thread to exit */
-	usb2_proc_unsetup(&info->done_p);
+	/* make sure that our done messages are not queued anywhere */
+	usb2_proc_mwait(info->done_p, &info->done_m[0], &info->done_m[1]);
+
+	USB_BUS_UNLOCK(info->bus);
 
 	/* free DMA'able memory, if any */
 	pc = info->dma_page_cache_start;
@@ -1811,7 +1811,7 @@ usb2_callback_ss_done_defer(struct usb2_xfer *xfer)
 	         * will have a Lock Order Reversal, LOR, if we try to
 	         * proceed !
 	         */
-		if (usb2_proc_msignal(&info->done_p,
+		if (usb2_proc_msignal(info->done_p,
 		    &info->done_m[0], &info->done_m[1])) {
 			/* ignore */
 		}
@@ -1851,7 +1851,7 @@ usb2_callback_wrapper(struct usb2_xfer_queue *pq)
 	         * will have a Lock Order Reversal, LOR, if we try to
 	         * proceed !
 	         */
-		if (usb2_proc_msignal(&info->done_p,
+		if (usb2_proc_msignal(info->done_p,
 		    &info->done_m[0], &info->done_m[1])) {
 			/* ignore */
 		}
@@ -2195,7 +2195,8 @@ usb2_pipe_start(struct usb2_xfer_queue *pq)
 				    udev, NULL, pipe);
 			} else if (udev->default_xfer[1]) {
 				info = udev->default_xfer[1]->xroot;
-				if (usb2_proc_msignal(&info->done_p,
+				if (usb2_proc_msignal(
+				    &info->bus->non_giant_callback_proc,
 				    &udev->cs_msg[0], &udev->cs_msg[1])) {
 					/* ignore */
 				}
diff --git a/sys/dev/usb2/core/usb2_transfer.h b/sys/dev/usb2/core/usb2_transfer.h
index 7e95be1a83f8..41494993c503 100644
--- a/sys/dev/usb2/core/usb2_transfer.h
+++ b/sys/dev/usb2/core/usb2_transfer.h
@@ -47,8 +47,8 @@ struct usb2_xfer_root {
 	struct usb2_done_msg done_m[2];
 	struct cv cv_drain;
 	struct usb2_dma_parent_tag dma_parent_tag;
-	struct usb2_process done_p;
 
+	struct usb2_process *done_p;	/* pointer to callback process */
 	void   *memory_base;
 	struct mtx *xfer_mtx;	/* cannot be changed during operation */
 	struct usb2_page_cache *dma_page_cache_start;