vpmadt032,wcte12xp: Use a timeout on the read/write commands and during load.

It is possible for poorly behaving hardware (and driver bugs) to lockup the
modprobe process by having it wait indefinitely for a command to complete that
never will.  DAHDI-451.

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@8003 a0bf4364-ded3-4de4-8d8a-66a801d63aff

2 files changed, 13 insertions, 21 deletions

diff --git a/drivers/dahdi/voicebus/GpakCust.c b/drivers/dahdi/voicebus/GpakCust.c
index 9491818..cce3308 100644
--- a/drivers/dahdi/voicebus/GpakCust.c
+++ b/drivers/dahdi/voicebus/GpakCust.c
@@ -133,9 +133,18 @@ static int vpmadt032_getreg_full_return(struct vpmadt032 *vpm, int pagechange,
 	u16 addr, u16 *outbuf, struct vpmadt032_cmd *cmd)
 {
 	unsigned long flags;
-	int ret = -EIO;
+	unsigned long ret;
 	BUG_ON(!cmd);
-	wait_for_completion(&cmd->complete);
+
+	/* We'll wait for 200ms */
+	ret = wait_for_completion_timeout(&cmd->complete, HZ/5);
+	if (unlikely(!ret)) {
+		spin_lock_irqsave(&vpm->list_lock, flags);
+		list_add_tail(&cmd->node, &vpm->free_cmds);
+		spin_unlock_irqrestore(&vpm->list_lock, flags);
+		return -EIO;
+	}
+
 	if (cmd->desc & __VPM150M_FIN) {
 		*outbuf = cmd->data;
 		cmd->desc = 0;
@@ -146,7 +155,7 @@ static int vpmadt032_getreg_full_return(struct vpmadt032 *vpm, int pagechange,
 	spin_lock_irqsave(&vpm->list_lock, flags);
 	list_add_tail(&cmd->node, &vpm->free_cmds);
 	spin_unlock_irqrestore(&vpm->list_lock, flags);
-	return ret;
+	return 0;
 }
 
 /* Read one of the registers on the VPMADT032 */
diff --git a/drivers/dahdi/voicebus/voicebus.c b/drivers/dahdi/voicebus/voicebus.c
index ffbe971..2646302 100644
--- a/drivers/dahdi/voicebus/voicebus.c
+++ b/drivers/dahdi/voicebus/voicebus.c
@@ -997,23 +997,6 @@ vb_clear_start_receive_bit(struct voicebus *vb)
 	VBUNLOCK(vb);
 }
 
-static unsigned long
-vb_wait_for_completion_timeout(struct completion *x, unsigned long timeout)
-{
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 11)
-	/* There is a race condition here.  If x->done is reset to 0
-	 * before the call to wait_for_completion after this thread wakes.
-	 */
-	timeout = wait_event_timeout(x->wait, x->done, timeout);
-	if (timeout)
-		wait_for_completion(x);
-
-	return timeout;
-#else
-	return wait_for_completion_timeout(x, timeout);
-#endif
-}
-
 /*!
  * \brief Stops the VoiceBus interface.
  *
@@ -1036,7 +1019,7 @@ voicebus_stop(struct voicebus *vb)
 	set_bit(STOP, &vb->flags);
 	vb_clear_start_transmit_bit(vb);
 	vb_clear_start_receive_bit(vb);
-	if (vb_wait_for_completion_timeout(&vb->stopped_completion, HZ)) {
+	if (wait_for_completion_timeout(&vb->stopped_completion, HZ)) {
 		BUG_ON(!vb_is_stopped(vb));
 	} else {
 		dev_warn(&vb->pdev->dev, "Timeout while waiting for board to "