USB: EHCI: don't refcount iso_stream structures
This patch (as1580) makes ehci_iso_stream structures behave more like
QHs, in that they will remain allocated until their isochronous
endpoint is disabled. This will come in useful in the future, when
periodic bandwidth gets allocated as an altsetting is installed rather
than on-the-fly.
For now, the change to the ehci_iso_stream lifetimes means that each
structure is always deallocated at exactly one spot in
ehci_endpoint_disable() and never used again. As a result, it is no
longer necessary to use reference counting on these things, and the
patch removes it.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 1e4f13c..11b2f21 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -934,7 +934,6 @@
INIT_LIST_HEAD(&stream->td_list);
INIT_LIST_HEAD(&stream->free_list);
stream->next_uframe = -1;
- stream->refcount = 1;
}
return stream;
}
@@ -1034,32 +1033,6 @@
stream->maxp = maxp;
}
-static void
-iso_stream_put(struct ehci_hcd *ehci, struct ehci_iso_stream *stream)
-{
- stream->refcount--;
-
- /* free whenever just a dev->ep reference remains.
- * not like a QH -- no persistent state (toggle, halt)
- */
- if (stream->refcount == 1) {
- // BUG_ON (!list_empty(&stream->td_list));
-
- if (stream->ep)
- stream->ep->hcpriv = NULL;
-
- kfree(stream);
- }
-}
-
-static inline struct ehci_iso_stream *
-iso_stream_get (struct ehci_iso_stream *stream)
-{
- if (likely (stream != NULL))
- stream->refcount++;
- return stream;
-}
-
static struct ehci_iso_stream *
iso_stream_find (struct ehci_hcd *ehci, struct urb *urb)
{
@@ -1080,7 +1053,6 @@
if (unlikely (stream == NULL)) {
stream = iso_stream_alloc(GFP_ATOMIC);
if (likely (stream != NULL)) {
- /* dev->ep owns the initial refcount */
ep->hcpriv = stream;
stream->ep = ep;
iso_stream_init(ehci, stream, urb->dev, urb->pipe,
@@ -1095,9 +1067,6 @@
stream = NULL;
}
- /* caller guarantees an eventual matching iso_stream_put */
- stream = iso_stream_get (stream);
-
spin_unlock_irqrestore (&ehci->lock, flags);
return stream;
}
@@ -1611,7 +1580,7 @@
itd = list_entry (iso_sched->td_list.next,
struct ehci_itd, itd_list);
list_move_tail (&itd->itd_list, &stream->td_list);
- itd->stream = iso_stream_get (stream);
+ itd->stream = stream;
itd->urb = urb;
itd_init (ehci, stream, itd);
}
@@ -1735,7 +1704,6 @@
dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
- iso_stream_put (ehci, stream);
done:
itd->urb = NULL;
@@ -1750,7 +1718,6 @@
start_free_itds(ehci);
}
- iso_stream_put(ehci, stream);
return retval;
}
@@ -1807,12 +1774,9 @@
itd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
else
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
-done_not_linked:
+ done_not_linked:
spin_unlock_irqrestore (&ehci->lock, flags);
-
-done:
- if (unlikely (status < 0))
- iso_stream_put (ehci, stream);
+ done:
return status;
}
@@ -2028,7 +1992,7 @@
sitd = list_entry (sched->td_list.next,
struct ehci_sitd, sitd_list);
list_move_tail (&sitd->sitd_list, &stream->td_list);
- sitd->stream = iso_stream_get (stream);
+ sitd->stream = stream;
sitd->urb = urb;
sitd_patch(ehci, stream, sitd, sched, packet);
@@ -2126,7 +2090,6 @@
dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
- iso_stream_put (ehci, stream);
done:
sitd->urb = NULL;
@@ -2141,7 +2104,6 @@
start_free_itds(ehci);
}
- iso_stream_put(ehci, stream);
return retval;
}
@@ -2195,12 +2157,9 @@
sitd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
else
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
-done_not_linked:
+ done_not_linked:
spin_unlock_irqrestore (&ehci->lock, flags);
-
-done:
- if (status < 0)
- iso_stream_put (ehci, stream);
+ done:
return status;
}