usb/host/fotg210: Add function scan_frame_queue()

checkpatch complains about too many leading tabs because the if
statement starts after 6 tabs:

scan_iosoc() -> for() -> while() -> switch() -> if() -> for() -> if()

There is also a goto statement going backwards in case of failure. This
patch creates a new inline function named scan_frame_queue() containing
the last 4 nesting levels, and removes the need of backwards goto,
making the code easier to read. After the patch it becomes:

scan_iosoc() -> for() -> while() -> scan_frame_queue()
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/fotg210-hcd.c

@@ -4609,35 +4609,14 @@ static int itd_submit(struct fotg210_hcd *fotg210, struct urb *urb,
 	return status;
 }
 
-/*-------------------------------------------------------------------------*/
-
-static void scan_isoc(struct fotg210_hcd *fotg210)
+static inline int scan_frame_queue(struct fotg210_hcd *fotg210, unsigned frame,
+		unsigned now_frame, bool live)
 {
-	unsigned	uf, now_frame, frame;
-	unsigned	fmask = fotg210->periodic_size - 1;
-	bool		modified, live;
-
-	/*
-	 * When running, scan from last scan point up to "now"
-	 * else clean up by scanning everything that's left.
-	 * Touches as few pages as possible:  cache-friendly.
-	 */
-	if (fotg210->rh_state >= FOTG210_RH_RUNNING) {
-		uf = fotg210_read_frame_index(fotg210);
-		now_frame = (uf >> 3) & fmask;
-		live = true;
-	} else  {
-		now_frame = (fotg210->next_frame - 1) & fmask;
-		live = false;
-	}
-	fotg210->now_frame = now_frame;
-
-	frame = fotg210->next_frame;
-	for (;;) {
+	unsigned uf;
+	bool modified;
 	union fotg210_shadow q, *q_p;
 	__hc32 type, *hw_p;
 
-restart:
 	/* scan each element in frame's queue for completions */
 	q_p = &fotg210->pshadow[frame];
 	hw_p = &fotg210->periodic[frame];
@@ -4645,7 +4624,7 @@ static void scan_isoc(struct fotg210_hcd *fotg210)
 	type = Q_NEXT_TYPE(fotg210, *hw_p);
 	modified = false;
 
-		while (q.ptr != NULL) {
+	while (q.ptr) {
 		switch (hc32_to_cpu(fotg210, type)) {
 		case Q_TYPE_ITD:
 			/* If this ITD is still active, leave it for
@@ -4695,8 +4674,38 @@ static void scan_isoc(struct fotg210_hcd *fotg210)
 
 		/* assume completion callbacks modify the queue */
 		if (unlikely(modified && fotg210->isoc_count > 0))
-				goto restart;
+			return -EINVAL;
 	}
+	return 0;
+}
+
+static void scan_isoc(struct fotg210_hcd *fotg210)
+{
+	unsigned uf, now_frame, frame, ret;
+	unsigned fmask = fotg210->periodic_size - 1;
+	bool live;
+
+	/*
+	 * When running, scan from last scan point up to "now"
+	 * else clean up by scanning everything that's left.
+	 * Touches as few pages as possible:  cache-friendly.
+	 */
+	if (fotg210->rh_state >= FOTG210_RH_RUNNING) {
+		uf = fotg210_read_frame_index(fotg210);
+		now_frame = (uf >> 3) & fmask;
+		live = true;
+	} else  {
+		now_frame = (fotg210->next_frame - 1) & fmask;
+		live = false;
+	}
+	fotg210->now_frame = now_frame;
+
+	frame = fotg210->next_frame;
+	for (;;) {
+		ret = 1;
+		while (ret != 0)
+			ret = scan_frame_queue(fotg210, frame,
+					now_frame, live);
 
 		/* Stop when we have reached the current frame */
 		if (frame == now_frame)