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path: root/drivers/usb/host/ehci-sched.c
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Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
-rw-r--r--drivers/usb/host/ehci-sched.c58
1 files changed, 42 insertions, 16 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index dce305bd62a5..1c771045ccaa 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1565,6 +1565,16 @@ itd_link_urb (
#define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
+/* Process and recycle a completed ITD. Return true iff its urb completed,
+ * and hence its completion callback probably added things to the hardware
+ * schedule.
+ *
+ * Note that we carefully avoid recycling this descriptor until after any
+ * completion callback runs, so that it won't be reused quickly. That is,
+ * assuming (a) no more than two urbs per frame on this endpoint, and also
+ * (b) only this endpoint's completions submit URBs. It seems some silicon
+ * corrupts things if you reuse completed descriptors very quickly...
+ */
static unsigned
itd_complete (
struct ehci_hcd *ehci,
@@ -1577,6 +1587,7 @@ itd_complete (
int urb_index = -1;
struct ehci_iso_stream *stream = itd->stream;
struct usb_device *dev;
+ unsigned retval = false;
/* for each uframe with a packet */
for (uframe = 0; uframe < 8; uframe++) {
@@ -1610,15 +1621,9 @@ itd_complete (
}
}
- usb_put_urb (urb);
- itd->urb = NULL;
- itd->stream = NULL;
- list_move (&itd->itd_list, &stream->free_list);
- iso_stream_put (ehci, stream);
-
/* handle completion now? */
if (likely ((urb_index + 1) != urb->number_of_packets))
- return 0;
+ goto done;
/* ASSERT: it's really the last itd for this urb
list_for_each_entry (itd, &stream->td_list, itd_list)
@@ -1628,6 +1633,7 @@ itd_complete (
/* give urb back to the driver ... can be out-of-order */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
+ retval = true;
urb = NULL;
/* defer stopping schedule; completion can submit */
@@ -1645,8 +1651,15 @@ itd_complete (
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
iso_stream_put (ehci, stream);
+ /* OK to recycle this ITD now that its completion callback ran. */
+done:
+ usb_put_urb(urb);
+ itd->urb = NULL;
+ itd->stream = NULL;
+ list_move(&itd->itd_list, &stream->free_list);
+ iso_stream_put(ehci, stream);
- return 1;
+ return retval;
}
/*-------------------------------------------------------------------------*/
@@ -1950,6 +1963,16 @@ sitd_link_urb (
#define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
| SITD_STS_XACT | SITD_STS_MMF)
+/* Process and recycle a completed SITD. Return true iff its urb completed,
+ * and hence its completion callback probably added things to the hardware
+ * schedule.
+ *
+ * Note that we carefully avoid recycling this descriptor until after any
+ * completion callback runs, so that it won't be reused quickly. That is,
+ * assuming (a) no more than two urbs per frame on this endpoint, and also
+ * (b) only this endpoint's completions submit URBs. It seems some silicon
+ * corrupts things if you reuse completed descriptors very quickly...
+ */
static unsigned
sitd_complete (
struct ehci_hcd *ehci,
@@ -1961,6 +1984,7 @@ sitd_complete (
int urb_index = -1;
struct ehci_iso_stream *stream = sitd->stream;
struct usb_device *dev;
+ unsigned retval = false;
urb_index = sitd->index;
desc = &urb->iso_frame_desc [urb_index];
@@ -1981,17 +2005,11 @@ sitd_complete (
desc->status = 0;
desc->actual_length = desc->length - SITD_LENGTH (t);
}
-
- usb_put_urb (urb);
- sitd->urb = NULL;
- sitd->stream = NULL;
- list_move (&sitd->sitd_list, &stream->free_list);
stream->depth -= stream->interval << 3;
- iso_stream_put (ehci, stream);
/* handle completion now? */
if ((urb_index + 1) != urb->number_of_packets)
- return 0;
+ goto done;
/* ASSERT: it's really the last sitd for this urb
list_for_each_entry (sitd, &stream->td_list, sitd_list)
@@ -2001,6 +2019,7 @@ sitd_complete (
/* give urb back to the driver */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
+ retval = true;
urb = NULL;
/* defer stopping schedule; completion can submit */
@@ -2018,8 +2037,15 @@ sitd_complete (
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
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);
+ iso_stream_put(ehci, stream);
- return 1;
+ return retval;
}
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