char: n_gsm: remove message filtering for contipated DLCI

The design of uplink flow control in the mux driver is
that for constipated channels data will backup into the
per-channel fifos, and any messages that make it to the
outbound message queue will still go out.
Code was added to also stop messages that were in the outbound
queue but this requires filtering through all the messages on the
queue for stopped dlcis and changes some of the mux logic unneccessarily.

The message fiiltering was removed to be in line w/ the original design
as the message filtering does not provide any solution.
Extra debug messages used during investigation were also removed.

Signed-off-by: samix.lebsir <samix.lebsir@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Dressage <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index db15b56..5f68f2a 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -691,10 +691,6 @@
 			msg = msg->next;
 			continue;
 		}
-		if (gsm->dlci[msg->addr]->constipated) {
-			msg = msg->next;
-			continue;
-		}
 		if (gsm->encoding != 0) {
 			gsm->txframe[0] = GSM1_SOF;
 			len = gsm_stuff_frame(msg->data,
@@ -748,8 +744,6 @@
 	u8 *dp = msg->data;
 	u8 *fcs = dp + msg->len;
 
-	WARN_ONCE(dlci->constipated, "%s: queueing from a constipated DLCI",
-		__func__);
 	/* Fill in the header */
 	if (gsm->encoding == 0) {
 		if (msg->len < 128)
@@ -956,9 +950,6 @@
 			break;
 		dlci = gsm->dlci[i];
 		if (dlci == NULL || dlci->constipated) {
-			if (dlci && (debug & 0x20))
-				pr_info("%s: DLCI %d is constipated",
-					__func__, i);
 			i++;
 			continue;
 		}
@@ -988,12 +979,8 @@
 	unsigned long flags;
 	int sweep;
 
-	if (dlci->constipated) {
-		if (debug & 0x20)
-			pr_info("%s: DLCI %d is constipated",
-				__func__, dlci->addr);
+	if (dlci->constipated) 
 		return;
-	}
 
 	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
 	/* If we have nothing running then we need to fire up */
@@ -1069,15 +1056,9 @@
 	/* Flow control/ready to communicate */
 	fc = (modem & MDM_FC) || !(modem & MDM_RTR);
 	if (fc && !dlci->constipated) {
-		if (debug & 0x20)
-			pr_info("%s: DLCI %d START constipated (tx_bytes=%d)",
-				__func__, dlci->addr, dlci->gsm->tx_bytes);
 		/* Need to throttle our output on this device */
 		dlci->constipated = 1;
 	} else if (!fc && dlci->constipated) {
-		if (debug & 0x20)
-			pr_info("%s: DLCI %d END constipated (tx_bytes=%d)",
-				__func__, dlci->addr, dlci->gsm->tx_bytes);
 		dlci->constipated = 0;
 		gsm_dlci_data_kick(dlci);
 	}
@@ -1241,8 +1222,6 @@
 		break;
 	case CMD_FCON:
 		/* Modem can accept data again */
-		if (debug & 0x20)
-			pr_info("%s: GSM END constipation", __func__);
 		gsm->constipated = 0;
 		gsm_control_reply(gsm, CMD_FCON, NULL, 0);
 		/* Kick the link in case it is idling */
@@ -1250,8 +1229,6 @@
 		break;
 	case CMD_FCOFF:
 		/* Modem wants us to STFU */
-		if (debug & 0x20)
-			pr_info("%s: GSM START constipation", __func__);
 		gsm->constipated = 1;
 		gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
 		break;