USB: EHCI: Fix isochronous URB leak

ehci-hcd uses usb_get_urb() and usb_put_urb() in an unbalanced way causing
isochronous URB's kref.counts incrementing once per usb_submit_urb() call.
The culprit is *usb being set to NULL when usb_put_urb() is called after URB
is given back.
Due to other fixes there is no need for ehci-hcd to deal with usb_get_urb()
nor usb_put_urb() anymore, so patch removes their usages in ehci-hcd.
Patch also makes ehci_to_hcd(ehci)->self.bandwidth_allocated adjust, if a
stream finishes.

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 07bcb931021b..1d0b49e3f192 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1536,7 +1536,7 @@ itd_link_urb (
                                         struct ehci_itd, itd_list);
                         list_move_tail (&itd->itd_list, &stream->td_list);
                         itd->stream = iso_stream_get (stream);
-                        itd->urb = usb_get_urb (urb);
+                        itd->urb = urb;
                         itd_init (ehci, stream, itd);
                 }
 
@@ -1645,7 +1645,7 @@ itd_complete (
         (void) disable_periodic(ehci);
         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
 
-        if (unlikely (list_empty (&stream->td_list))) {
+        if (unlikely(list_is_singular(&stream->td_list))) {
                 ehci_to_hcd(ehci)->self.bandwidth_allocated
                                 -= stream->bandwidth;
                 ehci_vdbg (ehci,
@@ -1656,7 +1656,6 @@ itd_complete (
         iso_stream_put (ehci, stream);
 
 done:
-        usb_put_urb(urb);
         itd->urb = NULL;
         if (ehci->clock_frame != itd->frame || itd->index[7] != -1) {
                 /* OK to recycle this ITD now. */
@@ -1949,7 +1948,7 @@ sitd_link_urb (
                                 struct ehci_sitd, sitd_list);
                 list_move_tail (&sitd->sitd_list, &stream->td_list);
                 sitd->stream = iso_stream_get (stream);
-                sitd->urb = usb_get_urb (urb);
+                sitd->urb = urb;
 
                 sitd_patch(ehci, stream, sitd, sched, packet);
                 sitd_link (ehci, (next_uframe >> 3) % ehci->periodic_size,
@@ -2034,7 +2033,7 @@ sitd_complete (
         (void) disable_periodic(ehci);
         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
 
-        if (list_empty (&stream->td_list)) {
+        if (list_is_singular(&stream->td_list)) {
                 ehci_to_hcd(ehci)->self.bandwidth_allocated
                                 -= stream->bandwidth;
                 ehci_vdbg (ehci,
@@ -2045,7 +2044,6 @@ sitd_complete (
         iso_stream_put (ehci, stream);
         /* OK to recycle this SITD now that its completion callback ran. */
 done:
-        usb_put_urb(urb);
         sitd->urb = NULL;
         sitd->stream = NULL;
         list_move(&sitd->sitd_list, &stream->free_list);