1 files changed, 61 insertions, 75 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 7cf3da7babf0..69ebee73c0c1 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -36,29 +36,6 @@
 
 static int ehci_get_frame (struct usb_hcd *hcd);
 
-#ifdef CONFIG_PCI
-
-static unsigned ehci_read_frame_index(struct ehci_hcd *ehci)
-{
-	unsigned uf;
-
-	/*
-	 * The MosChip MCS9990 controller updates its microframe counter
-	 * a little before the frame counter, and occasionally we will read
-	 * the invalid intermediate value.  Avoid problems by checking the
-	 * microframe number (the low-order 3 bits); if they are 0 then
-	 * re-read the register to get the correct value.
-	 */
-	uf = ehci_readl(ehci, &ehci->regs->frame_index);
-	if (unlikely(ehci->frame_index_bug && ((uf & 7) == 0)))
-		uf = ehci_readl(ehci, &ehci->regs->frame_index);
-	return uf;
-}
-
-#endif
-
-/*-------------------------------------------------------------------------*/
-
 /*
  * periodic_next_shadow - return "next" pointer on shadow list
  * @periodic: host pointer to qh/itd/sitd
@@ -1361,7 +1338,7 @@ sitd_slot_ok (
  * given EHCI_TUNE_FLS and the slop).  Or, write a smarter scheduler!
  */
 
-#define SCHEDULE_SLOP	80	/* microframes */
+#define SCHEDULING_DELAY	40	/* microframes */
 
 static int
 iso_stream_schedule (
@@ -1370,7 +1347,7 @@ iso_stream_schedule (
 	struct ehci_iso_stream	*stream
 )
 {
-	u32			now, next, start, period, span;
+	u32			now, base, next, start, period, span;
 	int			status;
 	unsigned		mod = ehci->periodic_size << 3;
 	struct ehci_iso_sched	*sched = urb->hcpriv;
@@ -1382,62 +1359,72 @@ iso_stream_schedule (
 		span <<= 3;
 	}
 
-	if (span > mod - SCHEDULE_SLOP) {
-		ehci_dbg (ehci, "iso request %p too long\n", urb);
-		status = -EFBIG;
-		goto fail;
-	}
-
 	now = ehci_read_frame_index(ehci) & (mod - 1);
 
 	/* Typical case: reuse current schedule, stream is still active.
 	 * Hopefully there are no gaps from the host falling behind
-	 * (irq delays etc), but if there are we'll take the next
-	 * slot in the schedule, implicitly assuming URB_ISO_ASAP.
+	 * (irq delays etc).  If there are, the behavior depends on
+	 * whether URB_ISO_ASAP is set.
 	 */
 	if (likely (!list_empty (&stream->td_list))) {
-		u32	excess;
 
-		/* For high speed devices, allow scheduling within the
-		 * isochronous scheduling threshold.  For full speed devices
-		 * and Intel PCI-based controllers, don't (work around for
-		 * Intel ICH9 bug).
-		 */
-		if (!stream->highspeed && ehci->fs_i_thresh)
-			next = now + ehci->i_thresh;
+		/* Take the isochronous scheduling threshold into account */
+		if (ehci->i_thresh)
+			next = now + ehci->i_thresh;	/* uframe cache */
 		else
-			next = now;
+			next = (now + 2 + 7) & ~0x07;	/* full frame cache */
 
-		/* Fell behind (by up to twice the slop amount)?
-		 * We decide based on the time of the last currently-scheduled
-		 * slot, not the time of the next available slot.
+		/*
+		 * Use ehci->last_iso_frame as the base.  There can't be any
+		 * TDs scheduled for earlier than that.
 		 */
-		excess = (stream->next_uframe - period - next) & (mod - 1);
-		if (excess >= mod - 2 * SCHEDULE_SLOP)
-			start = next + excess - mod + period *
-					DIV_ROUND_UP(mod - excess, period);
-		else
-			start = next + excess + period;
-		if (start - now >= mod) {
-			ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
-					urb, start - now - period, period,
-					mod);
-			status = -EFBIG;
+		base = ehci->last_iso_frame << 3;
+		next = (next - base) & (mod - 1);
+		start = (stream->next_uframe - base) & (mod - 1);
+
+		/* Is the schedule already full? */
+		if (unlikely(start < period)) {
+			ehci_dbg(ehci, "iso sched full %p (%u-%u < %u mod %u)\n",
+					urb, stream->next_uframe, base,
+					period, mod);
+			status = -ENOSPC;
 			goto fail;
 		}
+
+		/* Behind the scheduling threshold? */
+		if (unlikely(start < next)) {
+
+			/* USB_ISO_ASAP: Round up to the first available slot */
+			if (urb->transfer_flags & URB_ISO_ASAP)
+				start += (next - start + period - 1) & -period;
+
+			/*
+			 * Not ASAP: Use the next slot in the stream.  If
+			 * the entire URB falls before the threshold, fail.
+			 */
+			else if (start + span - period < next) {
+				ehci_dbg(ehci, "iso urb late %p (%u+%u < %u)\n",
+						urb, start + base,
+						span - period, next + base);
+				status = -EXDEV;
+				goto fail;
+			}
+		}
+
+		start += base;
 	}
 
 	/* need to schedule; when's the next (u)frame we could start?
 	 * this is bigger than ehci->i_thresh allows; scheduling itself
-	 * isn't free, the slop should handle reasonably slow cpus.  it
+	 * isn't free, the delay should handle reasonably slow cpus.  it
 	 * can also help high bandwidth if the dma and irq loads don't
 	 * jump until after the queue is primed.
 	 */
 	else {
 		int done = 0;
-		start = SCHEDULE_SLOP + (now & ~0x07);
 
-		/* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
+		base = now & ~0x07;
+		start = base + SCHEDULING_DELAY;
 
 		/* find a uframe slot with enough bandwidth.
 		 * Early uframes are more precious because full-speed
@@ -1464,19 +1451,16 @@ iso_stream_schedule (
 
 		/* no room in the schedule */
 		if (!done) {
-			ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n",
-				urb, now, now + mod);
+			ehci_dbg(ehci, "iso sched full %p", urb);
 			status = -ENOSPC;
 			goto fail;
 		}
 	}
 
 	/* Tried to schedule too far into the future? */
-	if (unlikely(start - now + span - period
-				>= mod - 2 * SCHEDULE_SLOP)) {
-		ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
-				urb, start - now, span - period,
-				mod - 2 * SCHEDULE_SLOP);
+	if (unlikely(start - base + span - period >= mod)) {
+		ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",
+				urb, start - base, span - period, mod);
 		status = -EFBIG;
 		goto fail;
 	}
@@ -1490,7 +1474,7 @@ iso_stream_schedule (
 
 	/* Make sure scan_isoc() sees these */
 	if (ehci->isoc_count == 0)
-		ehci->next_frame = now >> 3;
+		ehci->last_iso_frame = now >> 3;
 	return 0;
 
  fail:
@@ -1646,7 +1630,7 @@ static void itd_link_urb(
 
 	/* don't need that schedule data any more */
 	iso_sched_free (stream, iso_sched);
-	urb->hcpriv = NULL;
+	urb->hcpriv = stream;
 
 	++ehci->isoc_count;
 	enable_periodic(ehci);
@@ -1708,7 +1692,7 @@ static bool itd_complete(struct ehci_hcd *ehci, struct ehci_itd *itd)
 			urb->actual_length += desc->actual_length;
 		} else {
 			/* URB was too late */
-			desc->status = -EXDEV;
+			urb->error_count++;
 		}
 	}
 
@@ -2045,7 +2029,7 @@ static void sitd_link_urb(
 
 	/* don't need that schedule data any more */
 	iso_sched_free (stream, sched);
-	urb->hcpriv = NULL;
+	urb->hcpriv = stream;
 
 	++ehci->isoc_count;
 	enable_periodic(ehci);
@@ -2081,7 +2065,7 @@ static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
 	t = hc32_to_cpup(ehci, &sitd->hw_results);
 
 	/* report transfer status */
-	if (t & SITD_ERRS) {
+	if (unlikely(t & SITD_ERRS)) {
 		urb->error_count++;
 		if (t & SITD_STS_DBE)
 			desc->status = usb_pipein (urb->pipe)
@@ -2091,6 +2075,9 @@ static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
 			desc->status = -EOVERFLOW;
 		else /* XACT, MMF, etc */
 			desc->status = -EPROTO;
+	} else if (unlikely(t & SITD_STS_ACTIVE)) {
+		/* URB was too late */
+		urb->error_count++;
 	} else {
 		desc->status = 0;
 		desc->actual_length = desc->length - SITD_LENGTH(t);
@@ -2220,16 +2207,16 @@ static void scan_isoc(struct ehci_hcd *ehci)
 		now_frame = (uf >> 3) & fmask;
 		live = true;
 	} else  {
-		now_frame = (ehci->next_frame - 1) & fmask;
+		now_frame = (ehci->last_iso_frame - 1) & fmask;
 		live = false;
 	}
 	ehci->now_frame = now_frame;
 
-	frame = ehci->next_frame;
 	for (;;) {
 		union ehci_shadow	q, *q_p;
 		__hc32			type, *hw_p;
 
+		frame = ehci->last_iso_frame;
 restart:
 		/* scan each element in frame's queue for completions */
 		q_p = &ehci->pshadow [frame];
@@ -2334,7 +2321,6 @@ restart:
 		/* Stop when we have reached the current frame */
 		if (frame == now_frame)
 			break;
-		frame = (frame + 1) & fmask;
+		ehci->last_iso_frame = (frame + 1) & fmask;
 	}
-	ehci->next_frame = now_frame;
 }