xpp: a massive backport from DAHDI. From Xorcom branch-rel-6839-r6908 .

Sun Mar  1 2009 Oron Peled <oron@actcom.co.il> - xpp.r6795
  * Fix cases where the command_queue overflowed during initialization.
    - Also add a 'command_queue_length' parameter to xpp.ko
  * More migrations to sysfs:
    - Add a 'transport' attribute to our astribank devices which
      points to the usb device we use. E.g:
       /sys/bus/astribanks/devices/xbus-00/transport is symlinked to
       ../../../../../../devices/pci0000:00/0000:00:10.4/usb5/5-4
    - Move /proc/xpp/XBUS-??/XPD-??/span to
      /sys/bus/xpds/devices/??:?:?/span
    - Migrate from /proc/xpp/sync to:
      /sys/bus/astribanks/drivers/xppdrv/sync
    - New 'offhook' attribute in:
      /sys/bus/xpds/devices/??:?:?/offhook
  * PRI: change the "timing" priority to match the convention used by
         other PRI cards -- I.e: lower numbers (not 0) have higher
	 priority.
  * FXO: 
    - Power denial: create two module parameters instead of hard-coded
      constants (power_denial_safezone, power_denial_minlen).
      For sites that get non-standard power-denial signals from central
      office on offhook.
    - Don't hangup on power-denial, just notify Dahdi and wait for
    - Fix caller-id detection for the case central office sends it before
      first ring without any indication before.
      Asterisk's desicion.
Mon, Dec  8 2008 Oron Peled <oron@actcom.co.il> - xpp.r6430
  * PRI:
    - Match our span clocking priorities (in system.conf)
      to Digium -- this is a reversal of the previous state.
      Now lower numbers (greater than 0) are better.
    - Synchronization fixes for PRI ports other than 0.
    - Fix T1 CRC for some countries (e.g: China).
  * FXS: fix bug in VMWI detection if using old asterisk
    which does not provide ZT_VMWI ioctl().
  * FXO:
    - Improve caller_id_style module parameter. This provide a workaround
      for countries that send this information without any notification
      (reverse polarity, ring, etc.)
    - Don't force on-hook upon power-denial. So, loopstart devices
      would ignore these as expected.
  * Implement a flow-control to prevent user space (init_card_* scripts)
    from pressuring our command queue.


git-svn-id: http://svn.digium.com/svn/zaptel/branches/1.4@4631 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 28 insertions, 3 deletions

diff --git a/kernel/xpp/xframe_queue.c b/kernel/xpp/xframe_queue.c
index 5d11600..17632df 100644
--- a/kernel/xpp/xframe_queue.c
+++ b/kernel/xpp/xframe_queue.c
@@ -25,10 +25,34 @@ void xframe_queue_clearstats(struct xframe_queue *q)
 	q->worst_lag_usec = 0L;
 }
 
+static void __xframe_dump_queue(struct xframe_queue *q)
+{
+	xframe_t	*xframe;
+	int		i = 0;
+	char		prefix[30];
+	struct timeval	now;
+
+	do_gettimeofday(&now);
+	printk(KERN_DEBUG "%s: dump queue '%s' (first packet in each frame)\n",
+		THIS_MODULE->name,
+		q->name);
+	list_for_each_entry_reverse(xframe, &q->head, frame_list) {
+		xpacket_t	*pack = (xpacket_t *)&xframe->packets[0];
+		long		usec = usec_diff(&now, &xframe->tv_queued);
+		snprintf(prefix, ARRAY_SIZE(prefix), "  %3d> %5ld.%03ld msec",
+			i++, usec / 1000, usec % 1000);
+		dump_packet(prefix, pack, 1);
+	}
+}
+
 static bool __xframe_enqueue(struct xframe_queue *q, xframe_t *xframe)
 {
 	int			ret = 1;
 
+	if(unlikely(q->disabled)) {
+		ret = 0;
+		goto out;
+	}
 	if(q->count >= q->max_count) {
 		q->overflows++;
 		NOTICE("Overflow of %-15s: counts %3d, %3d, %3d worst %3d, overflows %3d worst_lag %02ld.%ld ms\n",
@@ -40,6 +64,7 @@ static bool __xframe_enqueue(struct xframe_queue *q, xframe_t *xframe)
 				q->overflows,
 				q->worst_lag_usec / 1000,
 				q->worst_lag_usec % 1000);
+		__xframe_dump_queue(q);
 		ret = 0;
 		goto out;
 	}
@@ -95,9 +120,9 @@ xframe_t *xframe_dequeue(struct xframe_queue *q)
 	spin_unlock_irqrestore(&q->lock, flags);
 	return frm;
 }
-void xframe_queue_disable(struct xframe_queue *q)
+void xframe_queue_disable(struct xframe_queue *q, bool disabled)
 {
-	q->max_count = 0;
+	q->disabled = disabled;
 }
 
 void xframe_queue_clear(struct xframe_queue *q)
@@ -106,7 +131,7 @@ void xframe_queue_clear(struct xframe_queue *q)
 	xbus_t		*xbus = q->priv;
 	int		i = 0;
 
-	xframe_queue_disable(q);
+	xframe_queue_disable(q, 1);
 	while((xframe = xframe_dequeue(q)) != NULL) {
 		transport_free_xframe(xbus, xframe);
 		i++;