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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.c152
1 files changed, 84 insertions, 68 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 80d99bce2b38..8a8e08a51ba3 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -119,7 +119,8 @@ periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
q = &q->fstn->fstn_next;
break;
case Q_TYPE_ITD:
- usecs += q->itd->usecs [uframe];
+ if (q->itd->hw_transaction[uframe])
+ usecs += q->itd->stream->usecs;
hw_p = &q->itd->hw_next;
q = &q->itd->itd_next;
break;
@@ -211,7 +212,7 @@ static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
* low/fullspeed transfer can "carry over" from one uframe to the next,
* since the TT just performs downstream transfers in sequence.
*
- * For example two seperate 100 usec transfers can start in the same uframe,
+ * For example two separate 100 usec transfers can start in the same uframe,
* and the second one would "carry over" 75 usecs into the next uframe.
*/
static void
@@ -1536,7 +1537,6 @@ itd_link_urb (
uframe = next_uframe & 0x07;
frame = next_uframe >> 3;
- itd->usecs [uframe] = stream->usecs;
itd_patch(ehci, itd, iso_sched, packet, uframe);
next_uframe += stream->interval;
@@ -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++) {
@@ -1610,30 +1621,21 @@ 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)
BUG_ON (itd->urb == urb);
*/
- /* give urb back to the driver ... can be out-of-order */
+ /* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
+ retval = true;
urb = NULL;
-
- /* defer stopping schedule; completion can submit */
ehci->periodic_sched--;
- if (unlikely (!ehci->periodic_sched))
- (void) disable_periodic (ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (unlikely (list_empty (&stream->td_list))) {
@@ -1645,8 +1647,15 @@ 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;
}
/*-------------------------------------------------------------------------*/
@@ -1712,8 +1721,6 @@ done:
return status;
}
-#ifdef CONFIG_USB_EHCI_SPLIT_ISO
-
/*-------------------------------------------------------------------------*/
/*
@@ -1950,6 +1957,16 @@ 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 +1978,7 @@ 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];
@@ -1981,32 +1999,23 @@ 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)
BUG_ON (sitd->urb == urb);
*/
- /* give urb back to the driver */
+ /* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
+ retval = true;
urb = NULL;
-
- /* defer stopping schedule; completion can submit */
ehci->periodic_sched--;
- if (!ehci->periodic_sched)
- (void) disable_periodic (ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (list_empty (&stream->td_list)) {
@@ -2018,8 +2027,15 @@ 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;
}
@@ -2082,26 +2098,6 @@ done:
return status;
}
-#else
-
-static inline int
-sitd_submit (struct ehci_hcd *ehci, struct urb *urb, gfp_t mem_flags)
-{
- ehci_dbg (ehci, "split iso support is disabled\n");
- return -ENOSYS;
-}
-
-static inline unsigned
-sitd_complete (
- struct ehci_hcd *ehci,
- struct ehci_sitd *sitd
-) {
- ehci_err (ehci, "sitd_complete %p?\n", sitd);
- return 0;
-}
-
-#endif /* USB_EHCI_SPLIT_ISO */
-
/*-------------------------------------------------------------------------*/
static void
@@ -2127,17 +2123,9 @@ scan_periodic (struct ehci_hcd *ehci)
for (;;) {
union ehci_shadow q, *q_p;
__hc32 type, *hw_p;
- unsigned uframes;
+ unsigned incomplete = false;
- /* don't scan past the live uframe */
frame = now_uframe >> 3;
- if (frame == (clock >> 3))
- uframes = now_uframe & 0x07;
- else {
- /* safe to scan the whole frame at once */
- now_uframe |= 0x07;
- uframes = 8;
- }
restart:
/* scan each element in frame's queue for completions */
@@ -2175,12 +2163,15 @@ restart:
q = q.fstn->fstn_next;
break;
case Q_TYPE_ITD:
- /* skip itds for later in the frame */
+ /* If this ITD is still active, leave it for
+ * later processing ... check the next entry.
+ */
rmb ();
- for (uf = live ? uframes : 8; uf < 8; uf++) {
+ for (uf = 0; uf < 8 && live; uf++) {
if (0 == (q.itd->hw_transaction [uf]
& ITD_ACTIVE(ehci)))
continue;
+ incomplete = true;
q_p = &q.itd->itd_next;
hw_p = &q.itd->hw_next;
type = Q_NEXT_TYPE(ehci,
@@ -2188,10 +2179,12 @@ restart:
q = *q_p;
break;
}
- if (uf != 8)
+ if (uf < 8 && live)
break;
- /* this one's ready ... HC won't cache the
+ /* Take finished ITDs out of the schedule
+ * and process them: recycle, maybe report
+ * URB completion. HC won't cache the
* pointer for much longer, if at all.
*/
*q_p = q.itd->itd_next;
@@ -2202,8 +2195,12 @@ restart:
q = *q_p;
break;
case Q_TYPE_SITD:
+ /* If this SITD is still active, leave it for
+ * later processing ... check the next entry.
+ */
if ((q.sitd->hw_results & SITD_ACTIVE(ehci))
&& live) {
+ incomplete = true;
q_p = &q.sitd->sitd_next;
hw_p = &q.sitd->hw_next;
type = Q_NEXT_TYPE(ehci,
@@ -2211,6 +2208,11 @@ restart:
q = *q_p;
break;
}
+
+ /* Take finished SITDs out of the schedule
+ * and process them: recycle, maybe report
+ * URB completion.
+ */
*q_p = q.sitd->sitd_next;
*hw_p = q.sitd->hw_next;
type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
@@ -2226,11 +2228,24 @@ restart:
}
/* assume completion callbacks modify the queue */
- if (unlikely (modified))
- goto restart;
+ if (unlikely (modified)) {
+ if (likely(ehci->periodic_sched > 0))
+ goto restart;
+ /* maybe we can short-circuit this scan! */
+ disable_periodic(ehci);
+ now_uframe = clock;
+ break;
+ }
}
- /* stop when we catch up to the HC */
+ /* If we can tell we caught up to the hardware, stop now.
+ * We can't advance our scan without collecting the ISO
+ * transfers that are still pending in this frame.
+ */
+ if (incomplete && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+ ehci->next_uframe = now_uframe;
+ break;
+ }
// FIXME: this assumes we won't get lapped when
// latencies climb; that should be rare, but...
@@ -2243,7 +2258,8 @@ restart:
if (now_uframe == clock) {
unsigned now;
- if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state))
+ if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
+ || ehci->periodic_sched == 0)
break;
ehci->next_uframe = now_uframe;
now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 09:53:11 +0100