Merge tag 'isdn-removal' of https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

Arnd Bergmann says:

====================
isdn: deprecate non-mISDN drivers

When isdn4linux came up in the context of another patch series, I
remembered that we had discussed removing it a while ago.

It turns out that the suggestion from Karsten Keil wa to remove I4L
in 2018 after the last public ISDN networks are shut down. This has
happened now (with a very small number of exceptions), so I guess it's
time to try again.

We currently have three ISDN stacks in the kernel: the original
isdn4linux (with the hisax driver), the newer CAPI (with four drivers),
and finally the mISDN stack (supporting roughly the same hardware as
hisax).

As far as I can tell, anyone using ISDN with mainline kernel drivers in
the past few years uses mISDN, and this is typically used for voice-only
PBX installations that don't require a public network.

The older stacks support additional features for data networks, but those
typically make no sense any more if there is no network to connect to.

My proposal for this time is to kill off isdn4linux entirely, as it seems
to have been unusable for quite a while. This code has been abandoned
for many years and it does cause problems for treewide maintenance as
it tends to do everything that we try to stop doing.
Birger Harzenetter mentioned that is is still using i4l in order to
make use of the 'divert' feature that is not part of mISDN, but has
otherwise moved on to mISDN for normal operation, like apparently
everyone else.

CAPI in turn is not quite as obsolete, but two of the drivers (avm
and hysdn) don't seem to be used at all, while another one (gigaset)
will stop being maintained as Paul Bolle is no longer able to
test it after the network gets shut down in September.
All three are now moved into drivers/staging to let others speak
up in case there are remaining users.
This leaves Bluetooth CMTP as the only remaining user of CAPI, but
Marcel Holtmann wishes to keep maintaining it.

For the discussion on version 1, see [2]
Unfortunately, Karsten Keil as the maintainer has not participated in
the discussion.

      Arnd

[1] https://patchwork.kernel.org/patch/8484861/#17900371
[2] https://listserv.isdn4linux.de/pipermail/isdn4linux/2019-April/thread.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 294 deletions

diff --git a/drivers/isdn/hisax/hscx_irq.c b/drivers/isdn/hisax/hscx_irq.c
deleted file mode 100644
index 0d7e783c8bef..000000000000
--- a/drivers/isdn/hisax/hscx_irq.c
+++ /dev/null
@@ -1,294 +0,0 @@
-/* $Id: hscx_irq.c,v 1.18.2.3 2004/02/11 13:21:34 keil Exp $
- *
- * low level b-channel stuff for Siemens HSCX
- *
- * Author       Karsten Keil
- * Copyright    by Karsten Keil      <keil@isdn4linux.de>
- *
- * This software may be used and distributed according to the terms
- * of the GNU General Public License, incorporated herein by reference.
- *
- * This is an include file for fast inline IRQ stuff
- *
- */
-
-
-static inline void
-waitforCEC(struct IsdnCardState *cs, int hscx)
-{
-	int to = 50;
-
-	while ((READHSCX(cs, hscx, HSCX_STAR) & 0x04) && to) {
-		udelay(1);
-		to--;
-	}
-	if (!to)
-		printk(KERN_WARNING "HiSax: waitforCEC timeout\n");
-}
-
-
-static inline void
-waitforXFW(struct IsdnCardState *cs, int hscx)
-{
-	int to = 50;
-
-	while (((READHSCX(cs, hscx, HSCX_STAR) & 0x44) != 0x40) && to) {
-		udelay(1);
-		to--;
-	}
-	if (!to)
-		printk(KERN_WARNING "HiSax: waitforXFW timeout\n");
-}
-
-static inline void
-WriteHSCXCMDR(struct IsdnCardState *cs, int hscx, u_char data)
-{
-	waitforCEC(cs, hscx);
-	WRITEHSCX(cs, hscx, HSCX_CMDR, data);
-}
-
-
-
-static void
-hscx_empty_fifo(struct BCState *bcs, int count)
-{
-	u_char *ptr;
-	struct IsdnCardState *cs = bcs->cs;
-
-	if ((cs->debug & L1_DEB_HSCX) && !(cs->debug & L1_DEB_HSCX_FIFO))
-		debugl1(cs, "hscx_empty_fifo");
-
-	if (bcs->hw.hscx.rcvidx + count > HSCX_BUFMAX) {
-		if (cs->debug & L1_DEB_WARN)
-			debugl1(cs, "hscx_empty_fifo: incoming packet too large");
-		WriteHSCXCMDR(cs, bcs->hw.hscx.hscx, 0x80);
-		bcs->hw.hscx.rcvidx = 0;
-		return;
-	}
-	ptr = bcs->hw.hscx.rcvbuf + bcs->hw.hscx.rcvidx;
-	bcs->hw.hscx.rcvidx += count;
-	READHSCXFIFO(cs, bcs->hw.hscx.hscx, ptr, count);
-	WriteHSCXCMDR(cs, bcs->hw.hscx.hscx, 0x80);
-	if (cs->debug & L1_DEB_HSCX_FIFO) {
-		char *t = bcs->blog;
-
-		t += sprintf(t, "hscx_empty_fifo %c cnt %d",
-			     bcs->hw.hscx.hscx ? 'B' : 'A', count);
-		QuickHex(t, ptr, count);
-		debugl1(cs, "%s", bcs->blog);
-	}
-}
-
-static void
-hscx_fill_fifo(struct BCState *bcs)
-{
-	struct IsdnCardState *cs = bcs->cs;
-	int more, count;
-	int fifo_size = test_bit(HW_IPAC, &cs->HW_Flags) ? 64 : 32;
-	u_char *ptr;
-
-	if ((cs->debug & L1_DEB_HSCX) && !(cs->debug & L1_DEB_HSCX_FIFO))
-		debugl1(cs, "hscx_fill_fifo");
-
-	if (!bcs->tx_skb)
-		return;
-	if (bcs->tx_skb->len <= 0)
-		return;
-
-	more = (bcs->mode == L1_MODE_TRANS) ? 1 : 0;
-	if (bcs->tx_skb->len > fifo_size) {
-		more = !0;
-		count = fifo_size;
-	} else
-		count = bcs->tx_skb->len;
-
-	waitforXFW(cs, bcs->hw.hscx.hscx);
-	ptr = bcs->tx_skb->data;
-	skb_pull(bcs->tx_skb, count);
-	bcs->tx_cnt -= count;
-	bcs->hw.hscx.count += count;
-	WRITEHSCXFIFO(cs, bcs->hw.hscx.hscx, ptr, count);
-	WriteHSCXCMDR(cs, bcs->hw.hscx.hscx, more ? 0x8 : 0xa);
-	if (cs->debug & L1_DEB_HSCX_FIFO) {
-		char *t = bcs->blog;
-
-		t += sprintf(t, "hscx_fill_fifo %c cnt %d",
-			     bcs->hw.hscx.hscx ? 'B' : 'A', count);
-		QuickHex(t, ptr, count);
-		debugl1(cs, "%s", bcs->blog);
-	}
-}
-
-static void
-hscx_interrupt(struct IsdnCardState *cs, u_char val, u_char hscx)
-{
-	u_char r;
-	struct BCState *bcs = cs->bcs + hscx;
-	struct sk_buff *skb;
-	int fifo_size = test_bit(HW_IPAC, &cs->HW_Flags) ? 64 : 32;
-	int count;
-
-	if (!test_bit(BC_FLG_INIT, &bcs->Flag))
-		return;
-
-	if (val & 0x80) {	/* RME */
-		r = READHSCX(cs, hscx, HSCX_RSTA);
-		if ((r & 0xf0) != 0xa0) {
-			if (!(r & 0x80)) {
-				if (cs->debug & L1_DEB_WARN)
-					debugl1(cs, "HSCX invalid frame");
-#ifdef ERROR_STATISTIC
-				bcs->err_inv++;
-#endif
-			}
-			if ((r & 0x40) && bcs->mode) {
-				if (cs->debug & L1_DEB_WARN)
-					debugl1(cs, "HSCX RDO mode=%d",
-						bcs->mode);
-#ifdef ERROR_STATISTIC
-				bcs->err_rdo++;
-#endif
-			}
-			if (!(r & 0x20)) {
-				if (cs->debug & L1_DEB_WARN)
-					debugl1(cs, "HSCX CRC error");
-#ifdef ERROR_STATISTIC
-				bcs->err_crc++;
-#endif
-			}
-			WriteHSCXCMDR(cs, hscx, 0x80);
-		} else {
-			count = READHSCX(cs, hscx, HSCX_RBCL) & (
-				test_bit(HW_IPAC, &cs->HW_Flags) ? 0x3f : 0x1f);
-			if (count == 0)
-				count = fifo_size;
-			hscx_empty_fifo(bcs, count);
-			if ((count = bcs->hw.hscx.rcvidx - 1) > 0) {
-				if (cs->debug & L1_DEB_HSCX_FIFO)
-					debugl1(cs, "HX Frame %d", count);
-				if (!(skb = dev_alloc_skb(count)))
-					printk(KERN_WARNING "HSCX: receive out of memory\n");
-				else {
-					skb_put_data(skb, bcs->hw.hscx.rcvbuf,
-						     count);
-					skb_queue_tail(&bcs->rqueue, skb);
-				}
-			}
-		}
-		bcs->hw.hscx.rcvidx = 0;
-		schedule_event(bcs, B_RCVBUFREADY);
-	}
-	if (val & 0x40) {	/* RPF */
-		hscx_empty_fifo(bcs, fifo_size);
-		if (bcs->mode == L1_MODE_TRANS) {
-			/* receive audio data */
-			if (!(skb = dev_alloc_skb(fifo_size)))
-				printk(KERN_WARNING "HiSax: receive out of memory\n");
-			else {
-				skb_put_data(skb, bcs->hw.hscx.rcvbuf,
-					     fifo_size);
-				skb_queue_tail(&bcs->rqueue, skb);
-			}
-			bcs->hw.hscx.rcvidx = 0;
-			schedule_event(bcs, B_RCVBUFREADY);
-		}
-	}
-	if (val & 0x10) {	/* XPR */
-		if (bcs->tx_skb) {
-			if (bcs->tx_skb->len) {
-				hscx_fill_fifo(bcs);
-				return;
-			} else {
-				if (test_bit(FLG_LLI_L1WAKEUP, &bcs->st->lli.flag) &&
-				    (PACKET_NOACK != bcs->tx_skb->pkt_type)) {
-					u_long	flags;
-					spin_lock_irqsave(&bcs->aclock, flags);
-					bcs->ackcnt += bcs->hw.hscx.count;
-					spin_unlock_irqrestore(&bcs->aclock, flags);
-					schedule_event(bcs, B_ACKPENDING);
-				}
-				dev_kfree_skb_irq(bcs->tx_skb);
-				bcs->hw.hscx.count = 0;
-				bcs->tx_skb = NULL;
-			}
-		}
-		if ((bcs->tx_skb = skb_dequeue(&bcs->squeue))) {
-			bcs->hw.hscx.count = 0;
-			test_and_set_bit(BC_FLG_BUSY, &bcs->Flag);
-			hscx_fill_fifo(bcs);
-		} else {
-			test_and_clear_bit(BC_FLG_BUSY, &bcs->Flag);
-			schedule_event(bcs, B_XMTBUFREADY);
-		}
-	}
-}
-
-static void
-hscx_int_main(struct IsdnCardState *cs, u_char val)
-{
-
-	u_char exval;
-	struct BCState *bcs;
-
-	if (val & 0x01) {
-		bcs = cs->bcs + 1;
-		exval = READHSCX(cs, 1, HSCX_EXIR);
-		if (exval & 0x40) {
-			if (bcs->mode == 1)
-				hscx_fill_fifo(bcs);
-			else {
-#ifdef ERROR_STATISTIC
-				bcs->err_tx++;
-#endif
-				/* Here we lost an TX interrupt, so
-				 * restart transmitting the whole frame.
-				 */
-				if (bcs->tx_skb) {
-					skb_push(bcs->tx_skb, bcs->hw.hscx.count);
-					bcs->tx_cnt += bcs->hw.hscx.count;
-					bcs->hw.hscx.count = 0;
-				}
-				WriteHSCXCMDR(cs, bcs->hw.hscx.hscx, 0x01);
-				if (cs->debug & L1_DEB_WARN)
-					debugl1(cs, "HSCX B EXIR %x Lost TX", exval);
-			}
-		} else if (cs->debug & L1_DEB_HSCX)
-			debugl1(cs, "HSCX B EXIR %x", exval);
-	}
-	if (val & 0xf8) {
-		if (cs->debug & L1_DEB_HSCX)
-			debugl1(cs, "HSCX B interrupt %x", val);
-		hscx_interrupt(cs, val, 1);
-	}
-	if (val & 0x02) {
-		bcs = cs->bcs;
-		exval = READHSCX(cs, 0, HSCX_EXIR);
-		if (exval & 0x40) {
-			if (bcs->mode == L1_MODE_TRANS)
-				hscx_fill_fifo(bcs);
-			else {
-				/* Here we lost an TX interrupt, so
-				 * restart transmitting the whole frame.
-				 */
-#ifdef ERROR_STATISTIC
-				bcs->err_tx++;
-#endif
-				if (bcs->tx_skb) {
-					skb_push(bcs->tx_skb, bcs->hw.hscx.count);
-					bcs->tx_cnt += bcs->hw.hscx.count;
-					bcs->hw.hscx.count = 0;
-				}
-				WriteHSCXCMDR(cs, bcs->hw.hscx.hscx, 0x01);
-				if (cs->debug & L1_DEB_WARN)
-					debugl1(cs, "HSCX A EXIR %x Lost TX", exval);
-			}
-		} else if (cs->debug & L1_DEB_HSCX)
-			debugl1(cs, "HSCX A EXIR %x", exval);
-	}
-	if (val & 0x04) {
-		exval = READHSCX(cs, 0, HSCX_ISTA);
-		if (cs->debug & L1_DEB_HSCX)
-			debugl1(cs, "HSCX A interrupt %x", exval);
-		hscx_interrupt(cs, exval, 0);
-	}
-}