mISDN: Allow to set a minimum length for transparent data

If the FIFO of the card is small, many short messages are queued up to
the upper layers and the userspace. This change allows the applications
to set a minimum datalen they want from the drivers.
Create a common control function to avoid code duplication in each
driver.

Signed-off-by: Karsten Keil <kkeil@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hardware/mISDN/mISDNisar.c

@@ -446,7 +446,7 @@ isar_rcv_frame(struct isar_ch *ch)
 			break;
 		}
 		rcv_mbox(ch->is, skb_put(ch->bch.rx_skb, ch->is->clsb));
-		recv_Bchannel(&ch->bch, 0);
+		recv_Bchannel(&ch->bch, 0, false);
 		break;
 	case ISDN_P_B_HDLC:
 		maxlen = bchannel_get_rxbuf(&ch->bch, ch->is->clsb);
@@ -481,7 +481,7 @@ isar_rcv_frame(struct isar_ch *ch)
 				break;
 			}
 			skb_trim(ch->bch.rx_skb, ch->bch.rx_skb->len - 2);
-			recv_Bchannel(&ch->bch, 0);
+			recv_Bchannel(&ch->bch, 0, false);
 		}
 		break;
 	case ISDN_P_B_T30_FAX:
@@ -517,7 +517,7 @@ isar_rcv_frame(struct isar_ch *ch)
 				ch->state = STFAX_ESCAPE;
 				/* set_skb_flag(skb, DF_NOMOREDATA); */
 			}
-			recv_Bchannel(&ch->bch, 0);
+			recv_Bchannel(&ch->bch, 0, false);
 			if (ch->is->cmsb & SART_NMD)
 				deliver_status(ch, HW_MOD_NOCARR);
 			break;
@@ -557,7 +557,7 @@ isar_rcv_frame(struct isar_ch *ch)
 				break;
 			}
 			skb_trim(ch->bch.rx_skb, ch->bch.rx_skb->len - 2);
-			recv_Bchannel(&ch->bch, 0);
+			recv_Bchannel(&ch->bch, 0, false);
 		}
 		if (ch->is->cmsb & SART_NMD) { /* ABORT */
 			pr_debug("%s: isar_rcv_frame: no more data\n",
@@ -1554,20 +1554,7 @@ isar_l2l1(struct mISDNchannel *ch, struct sk_buff *skb)
 static int
 channel_bctrl(struct bchannel *bch, struct mISDN_ctrl_req *cq)
 {
-	int	ret = 0;
-
-	switch (cq->op) {
-	case MISDN_CTRL_GETOP:
-		cq->op = 0;
-		break;
-		/* Nothing implemented yet */
-	case MISDN_CTRL_FILL_EMPTY:
-	default:
-		pr_info("%s: unknown Op %x\n", __func__, cq->op);
-		ret = -EINVAL;
-		break;
-	}
-	return ret;
+	return mISDN_ctrl_bchannel(bch, cq);
 }
 
 static int
@@ -1665,7 +1652,7 @@ mISDNisar_init(struct isar_hw *isar, void *hw)
 	isar->hw = hw;
 	for (i = 0; i < 2; i++) {
 		isar->ch[i].bch.nr = i + 1;
-		mISDN_initbchannel(&isar->ch[i].bch, MAX_DATA_MEM);
+		mISDN_initbchannel(&isar->ch[i].bch, MAX_DATA_MEM, 32);
 		isar->ch[i].bch.ch.nr = i + 1;
 		isar->ch[i].bch.ch.send = &isar_l2l1;
 		isar->ch[i].bch.ch.ctrl = isar_bctrl;