From f1cfbde80ad6d01f1d61c3608579c93c21b470d3 Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <riastradh@NetBSD.org>
Date: Thu, 20 Feb 2020 14:56:12 +0000
Subject: [PATCH] Teach usbd_close_pipe to wait for endpoint stall task.

Nix usbd_kill_pipe now that it's redundant.

Two minor additional changes:

- usbd_close_pipe now drops ue_refcnt after upm_close, not before.
  => Not sure this matters a great deal but it will ensure that if
     USBD_EXCLUSIVE_USE is set then usbd_open_pipe will not reuse the
     endpoint until after upm_close _and_ the clear-endpoint-stall
     task are complete.

- usbd_close_pipe just unlocks once, not twice with a dance around
  destroying the intrxfer.  The unlock dance didn't do anything.
---
 sys/dev/usb/usb_subr.c | 32 ++++++++++++--------------------
 sys/dev/usb/usbdi.c    | 11 +++++------
 sys/dev/usb/usbdivar.h |  1 -
 3 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/sys/dev/usb/usb_subr.c b/sys/dev/usb/usb_subr.c
index a6adc7ffa1db..bdd6e91847a5 100644
--- a/sys/dev/usb/usb_subr.c
+++ b/sys/dev/usb/usb_subr.c
@@ -791,20 +791,6 @@ usbd_setup_pipe_flags(struct usbd_device *dev, struct usbd_interface *iface,
 	return USBD_NORMAL_COMPLETION;
 }
 
-/* Abort the device control pipe. */
-void
-usbd_kill_pipe(struct usbd_pipe *pipe)
-{
-	usbd_abort_pipe(pipe);
-	usbd_lock_pipe(pipe);
-	pipe->up_methods->upm_close(pipe);
-	usbd_unlock_pipe(pipe);
-	usb_rem_task_wait(pipe->up_dev, &pipe->up_async_task, USB_TASKQ_DRIVER,
-	    NULL);
-	pipe->up_endpoint->ue_refcnt--;
-	kmem_free(pipe, pipe->up_dev->ud_bus->ub_pipesize);
-}
-
 int
 usbd_getnewaddr(struct usbd_bus *bus)
 {
@@ -1259,7 +1245,8 @@ usbd_new_device(device_t parent, struct usbd_bus *bus, int depth, int speed,
 	USETW(dev->ud_ep0desc.wMaxPacketSize, dd->bMaxPacketSize);
 
 	/* Re-establish the default pipe with the new MPS. */
-	usbd_kill_pipe(dev->ud_pipe0);
+	usbd_abort_pipe(dev->ud_pipe0);
+	usbd_close_pipe(dev->ud_pipe0);
 	dev->ud_pipe0 = NULL;
 	err = usbd_setup_pipe_flags(dev, 0, &dev->ud_ep0, USBD_DEFAULT_INTERVAL,
 	    &dev->ud_pipe0, USBD_MPSAFE);
@@ -1285,7 +1272,8 @@ usbd_new_device(device_t parent, struct usbd_bus *bus, int depth, int speed,
 	bus->ub_devices[usb_addr2dindex(addr)] = dev;
 
 	/* Re-establish the default pipe with the new address. */
-	usbd_kill_pipe(dev->ud_pipe0);
+	usbd_abort_pipe(dev->ud_pipe0);
+	usbd_close_pipe(dev->ud_pipe0);
 	dev->ud_pipe0 = NULL;
 	err = usbd_setup_pipe_flags(dev, 0, &dev->ud_ep0, USBD_DEFAULT_INTERVAL,
 	    &dev->ud_pipe0, USBD_MPSAFE);
@@ -1381,8 +1369,10 @@ usbd_remove_device(struct usbd_device *dev, struct usbd_port *up)
 	USBHIST_CALLARGS(usbdebug, "dev %#jx up %#jx",
 	    (uintptr_t)dev, (uintptr_t)up, 0, 0);
 
-	if (dev->ud_pipe0 != NULL)
-		usbd_kill_pipe(dev->ud_pipe0);
+	if (dev->ud_pipe0 != NULL) {
+		usbd_abort_pipe(dev->ud_pipe0);
+		usbd_close_pipe(dev->ud_pipe0);
+	}
 	up->up_dev = NULL;
 	dev->ud_bus->ub_devices[usb_addr2dindex(dev->ud_addr)] = NULL;
 
@@ -1551,8 +1541,10 @@ usb_free_device(struct usbd_device *dev)
 {
 	int ifcidx, nifc;
 
-	if (dev->ud_pipe0 != NULL)
-		usbd_kill_pipe(dev->ud_pipe0);
+	if (dev->ud_pipe0 != NULL) {
+		usbd_abort_pipe(dev->ud_pipe0);
+		usbd_close_pipe(dev->ud_pipe0);
+	}
 	if (dev->ud_ifaces != NULL) {
 		nifc = dev->ud_cdesc->bNumInterface;
 		for (ifcidx = 0; ifcidx < nifc; ifcidx++)
diff --git a/sys/dev/usb/usbdi.c b/sys/dev/usb/usbdi.c
index 6f5803706477..d6a853a28390 100644
--- a/sys/dev/usb/usbdi.c
+++ b/sys/dev/usb/usbdi.c
@@ -316,17 +316,16 @@ usbd_close_pipe(struct usbd_pipe *pipe)
 	KASSERT(SIMPLEQ_EMPTY(&pipe->up_queue));
 
 	LIST_REMOVE(pipe, up_next);
+	pipe->up_methods->upm_close(pipe);
+	usb_rem_task_wait(pipe->up_dev, &pipe->up_async_task, USB_TASKQ_DRIVER,
+	    NULL);
 	pipe->up_endpoint->ue_refcnt--;
 
-	pipe->up_methods->upm_close(pipe);
+	usbd_unlock_pipe(pipe);
 
-	if (pipe->up_intrxfer != NULL) {
-	    	usbd_unlock_pipe(pipe);
+	if (pipe->up_intrxfer != NULL)
 		usbd_destroy_xfer(pipe->up_intrxfer);
-		usbd_lock_pipe(pipe);
-	}
 
-	usbd_unlock_pipe(pipe);
 	kmem_free(pipe, pipe->up_dev->ud_bus->ub_pipesize);
 
 	return USBD_NORMAL_COMPLETION;
diff --git a/sys/dev/usb/usbdivar.h b/sys/dev/usb/usbdivar.h
index eb16853f71c6..4ac85b677351 100644
--- a/sys/dev/usb/usbdivar.h
+++ b/sys/dev/usb/usbdivar.h
@@ -346,7 +346,6 @@ usbd_status	usb_insert_transfer(struct usbd_xfer *);
 void		usb_transfer_complete(struct usbd_xfer *);
 int		usb_disconnect_port(struct usbd_port *, device_t, int);
 
-void		usbd_kill_pipe(struct usbd_pipe *);
 usbd_status	usbd_attach_roothub(device_t, struct usbd_device *);
 usbd_status	usbd_probe_and_attach(device_t, struct usbd_device *, int, int);