[PATCH v2 01/10] usb: host: ehci-sched: refactor scan_isoc function

[Geyslan G. Bem]

This patch removes an infinite 'for' loop and makes use of the already
existing 'restart' tag instead, reducing one leading tab.

It also puts the easier evaluation (live variable) to be the first in
two conditionals.

  if (live && frame == now_frame) { ...

  if (live && ((frame == now_frame) || ...

The comments and code were corrected conforming file coding style.

Tested by compilation only.
Caught by checkpatch:
 WARNING: Too many leading tabs - consider code refactoring

Signed-off-by: Geyslan G. Bem <geyslan@xxxxxxxxx>
---
  v2:
    Fixes file coding indentation.
    Puts 'live' variable as the first evaluation in two ifs.
---
 drivers/usb/host/ehci-sched.c | 201 +++++++++++++++++++++---------------------
 1 file changed, 100 insertions(+), 101 deletions(-)

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index f9a3327..eb14143 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -2379,9 +2379,11 @@ static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
 
 static void scan_isoc(struct ehci_hcd *ehci)
 {
-	unsigned	uf, now_frame, frame;
-	unsigned	fmask = ehci->periodic_size - 1;
-	bool		modified, live;
+	unsigned		uf, now_frame, frame;
+	unsigned		fmask = ehci->periodic_size - 1;
+	bool			modified, live;
+	union ehci_shadow	q, *q_p;
+	__hc32			type, *hw_p;
 
 	/*
 	 * When running, scan from last scan point up to "now"
@@ -2399,119 +2401,116 @@ static void scan_isoc(struct ehci_hcd *ehci)
 	ehci->now_frame = now_frame;
 
 	frame = ehci->last_iso_frame;
-	for (;;) {
-		union ehci_shadow	q, *q_p;
-		__hc32			type, *hw_p;
 
 restart:
-		/* scan each element in frame's queue for completions */
-		q_p = &ehci->pshadow [frame];
-		hw_p = &ehci->periodic [frame];
-		q.ptr = q_p->ptr;
-		type = Q_NEXT_TYPE(ehci, *hw_p);
-		modified = false;
-
-		while (q.ptr != NULL) {
-			switch (hc32_to_cpu(ehci, type)) {
-			case Q_TYPE_ITD:
-				/* If this ITD is still active, leave it for
-				 * later processing ... check the next entry.
-				 * No need to check for activity unless the
-				 * frame is current.
-				 */
-				if (frame == now_frame && live) {
-					rmb();
-					for (uf = 0; uf < 8; uf++) {
-						if (q.itd->hw_transaction[uf] &
-							    ITD_ACTIVE(ehci))
-							break;
-					}
-					if (uf < 8) {
-						q_p = &q.itd->itd_next;
-						hw_p = &q.itd->hw_next;
-						type = Q_NEXT_TYPE(ehci,
-							q.itd->hw_next);
-						q = *q_p;
+	/* Scan each element in frame's queue for completions */
+	q_p = &ehci->pshadow[frame];
+	hw_p = &ehci->periodic[frame];
+	q.ptr = q_p->ptr;
+	type = Q_NEXT_TYPE(ehci, *hw_p);
+	modified = false;
+
+	while (q.ptr != NULL) {
+		switch (hc32_to_cpu(ehci, type)) {
+		case Q_TYPE_ITD:
+			/*
+			 * If this ITD is still active, leave it for
+			 * later processing ... check the next entry.
+			 * No need to check for activity unless the
+			 * frame is current.
+			 */
+			if (live && frame == now_frame) {
+				rmb();
+				for (uf = 0; uf < 8; uf++) {
+					if (q.itd->hw_transaction[uf] &
+							ITD_ACTIVE(ehci))
 						break;
-					}
 				}
-
-				/* 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;
-				if (!ehci->use_dummy_qh ||
-				    q.itd->hw_next != EHCI_LIST_END(ehci))
-					*hw_p = q.itd->hw_next;
-				else
-					*hw_p = cpu_to_hc32(ehci,
-							ehci->dummy->qh_dma);
-				type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
-				wmb();
-				modified = itd_complete (ehci, q.itd);
-				q = *q_p;
-				break;
-			case Q_TYPE_SITD:
-				/* If this SITD is still active, leave it for
-				 * later processing ... check the next entry.
-				 * No need to check for activity unless the
-				 * frame is current.
-				 */
-				if (((frame == now_frame) ||
-				     (((frame + 1) & fmask) == now_frame))
-				    && live
-				    && (q.sitd->hw_results &
-					SITD_ACTIVE(ehci))) {
-
-					q_p = &q.sitd->sitd_next;
-					hw_p = &q.sitd->hw_next;
+				if (uf < 8) {
+					q_p = &q.itd->itd_next;
+					hw_p = &q.itd->hw_next;
 					type = Q_NEXT_TYPE(ehci,
-							q.sitd->hw_next);
+							q.itd->hw_next);
 					q = *q_p;
 					break;
 				}
+			}
+
+			/*
+			 * 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;
+			if (!ehci->use_dummy_qh ||
+					q.itd->hw_next != EHCI_LIST_END(ehci))
+				*hw_p = q.itd->hw_next;
+			else
+				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
+			type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
+			wmb();
+			modified = itd_complete(ehci, q.itd);
+			q = *q_p;
+			break;
+		case Q_TYPE_SITD:
+			/*
+			 * If this SITD is still active, leave it for
+			 * later processing ... check the next entry.
+			 * No need to check for activity unless the
+			 * frame is current.
+			 */
+			if (live && ((frame == now_frame) ||
+					(((frame + 1) & fmask) == now_frame))
+				&& (q.sitd->hw_results & SITD_ACTIVE(ehci))) {
 
-				/* Take finished SITDs out of the schedule
-				 * and process them:  recycle, maybe report
-				 * URB completion.
-				 */
-				*q_p = q.sitd->sitd_next;
-				if (!ehci->use_dummy_qh ||
-				    q.sitd->hw_next != EHCI_LIST_END(ehci))
-					*hw_p = q.sitd->hw_next;
-				else
-					*hw_p = cpu_to_hc32(ehci,
-							ehci->dummy->qh_dma);
+				q_p = &q.sitd->sitd_next;
+				hw_p = &q.sitd->hw_next;
 				type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
-				wmb();
-				modified = sitd_complete (ehci, q.sitd);
 				q = *q_p;
 				break;
-			default:
-				ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
-					type, frame, q.ptr);
-				// BUG ();
-				/* FALL THROUGH */
-			case Q_TYPE_QH:
-			case Q_TYPE_FSTN:
-				/* End of the iTDs and siTDs */
-				q.ptr = NULL;
-				break;
 			}
 
-			/* assume completion callbacks modify the queue */
-			if (unlikely(modified && ehci->isoc_count > 0))
-				goto restart;
-		}
-
-		/* Stop when we have reached the current frame */
-		if (frame == now_frame)
+			/*
+			 * Take finished SITDs out of the schedule
+			 * and process them:  recycle, maybe report
+			 * URB completion.
+			 */
+			*q_p = q.sitd->sitd_next;
+			if (!ehci->use_dummy_qh ||
+					q.sitd->hw_next != EHCI_LIST_END(ehci))
+				*hw_p = q.sitd->hw_next;
+			else
+				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
+			type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
+			wmb();
+			modified = sitd_complete(ehci, q.sitd);
+			q = *q_p;
 			break;
+		default:
+			ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
+					type, frame, q.ptr);
+			/* BUG(); */
+			/* FALL THROUGH */
+		case Q_TYPE_QH:
+		case Q_TYPE_FSTN:
+			/* End of the iTDs and siTDs */
+			q.ptr = NULL;
+			break;
+		}
 
-		/* The last frame may still have active siTDs */
-		ehci->last_iso_frame = frame;
-		frame = (frame + 1) & fmask;
+		/* Assume completion callbacks modify the queue */
+		if (unlikely(modified && ehci->isoc_count > 0))
+			goto restart;
 	}
+
+	/* Stop when we have reached the current frame */
+	if (frame == now_frame)
+		return;
+
+	/* The last frame may still have active siTDs */
+	ehci->last_iso_frame = frame;
+	frame = (frame + 1) & fmask;
+
+	goto restart;
 }
-- 
2.6.3

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