UHCI: fix bandwidth allocation

This patch (as840) fixes the bandwidth allocation mechanism in
uhci-hcd.  It has never worked correctly.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/uhci-debug.c

@@ -168,9 +168,13 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 			space, "", qh, qtype,
 			le32_to_cpu(qh->link), le32_to_cpu(element));
 	if (qh->type == USB_ENDPOINT_XFER_ISOC)
-		out += sprintf(out, "%*s    period %d frame %x desc [%p]\n",
-				space, "", qh->period, qh->iso_frame,
-				qh->iso_packet_desc);
+		out += sprintf(out, "%*s    period %d phase %d load %d us, "
+				"frame %x desc [%p]\n",
+				space, "", qh->period, qh->phase, qh->load,
+				qh->iso_frame, qh->iso_packet_desc);
+	else if (qh->type == USB_ENDPOINT_XFER_INT)
+		out += sprintf(out, "%*s    period %d phase %d load %d us\n",
+				space, "", qh->period, qh->phase, qh->load);
 
 	if (element & UHCI_PTR_QH)
 		out += sprintf(out, "%*s  Element points to QH (bug?)\n", space, "");
@@ -352,6 +356,17 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 	out += uhci_show_root_hub_state(uhci, out, len - (out - buf));
 	out += sprintf(out, "HC status\n");
 	out += uhci_show_status(uhci, out, len - (out - buf));
+
+	out += sprintf(out, "Periodic load table\n");
+	for (i = 0; i < MAX_PHASE; ++i) {
+		out += sprintf(out, "\t%d", uhci->load[i]);
+		if (i % 8 == 7)
+			*out++ = '\n';
+	}
+	out += sprintf(out, "Total: %d, #INT: %d, #ISO: %d\n",
+			uhci->total_load,
+			uhci_to_hcd(uhci)->self.bandwidth_int_reqs,
+			uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs);
 	if (debug <= 1)
 		return out - buf;
 

drivers/usb/host/uhci-hcd.h

@@ -83,6 +83,7 @@
 #define UHCI_MAX_SOF_NUMBER	2047	/* in an SOF packet */
 #define CAN_SCHEDULE_FRAMES	1000	/* how far in the future frames
 					 * can be scheduled */
+#define MAX_PHASE		32	/* Periodic scheduling length */
 
 /* When no queues need Full-Speed Bandwidth Reclamation,
  * delay this long before turning FSBR off */
@@ -141,6 +142,8 @@ struct uhci_qh {
 	unsigned long advance_jiffies;	/* Time of last queue advance */
 	unsigned int unlink_frame;	/* When the QH was unlinked */
 	unsigned int period;		/* For Interrupt and Isochronous QHs */
+	short phase;			/* Between 0 and period-1 */
+	short load;			/* Periodic time requirement, in us */
 	unsigned int iso_frame;		/* Frame # for iso_packet_desc */
 	int iso_status;			/* Status for Isochronous URBs */
 
@@ -153,6 +156,8 @@ struct uhci_qh {
 	unsigned int needs_fixup:1;	/* Must fix the TD toggle values */
 	unsigned int is_stopped:1;	/* Queue was stopped by error/unlink */
 	unsigned int wait_expired:1;	/* QH_WAIT_TIMEOUT has expired */
+	unsigned int bandwidth_reserved:1;	/* Periodic bandwidth has
+						 * been allocated */
 } __attribute__((aligned(16)));
 
 /*
@@ -414,6 +419,9 @@ struct uhci_hcd {
 
 	wait_queue_head_t waitqh;		/* endpoint_disable waiters */
 	int num_waiting;			/* Number of waiters */
+
+	int total_load;				/* Sum of array values */
+	short load[MAX_PHASE];			/* Periodic allocations */
 };
 
 /* Convert between a usb_hcd pointer and the corresponding uhci_hcd */