[01/35] tty: remove broken r3964 line discipline
diff mbox series

Message ID 20210505091928.22010-2-jslaby@suse.cz
State New, archived
Headers show
Series
  • tty cleanup for 5.14
Related show

Commit Message

Jiri Slaby May 5, 2021, 9:18 a.m. UTC
Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the line discipline for good.

Three remarks:
* we remove also the uapi header (as noone is able to use that interface
  anyway)
* we do *not* remove the N_R3964 constant definition from tty.h, so it
  remains reserved.
* in_interrupt() check is now removed from vt's con_put_char. Noone else
  calls tty_operations::put_char from interrupt context.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/powerpc/configs/ppc6xx_defconfig |    1 -
 drivers/char/Kconfig                  |   13 -
 drivers/tty/Makefile                  |    1 -
 drivers/tty/n_r3964.c                 | 1283 -------------------------
 drivers/tty/vt/vt.c                   |    2 -
 include/linux/n_r3964.h               |  175 ----
 include/uapi/linux/n_r3964.h          |   99 --
 7 files changed, 1574 deletions(-)
 delete mode 100644 drivers/tty/n_r3964.c
 delete mode 100644 include/linux/n_r3964.h
 delete mode 100644 include/uapi/linux/n_r3964.h

Comments

Greg Kroah-Hartman May 5, 2021, 9:26 a.m. UTC | #1
On Wed, May 05, 2021 at 11:18:54AM +0200, Jiri Slaby wrote:
> Noone stepped up in the past two years since it was marked as BROKEN by
> commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
> Remove the line discipline for good.
> 
> Three remarks:
> * we remove also the uapi header (as noone is able to use that interface
>   anyway)
> * we do *not* remove the N_R3964 constant definition from tty.h, so it
>   remains reserved.
> * in_interrupt() check is now removed from vt's con_put_char. Noone else
>   calls tty_operations::put_char from interrupt context.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> ---
>  arch/powerpc/configs/ppc6xx_defconfig |    1 -
>  drivers/char/Kconfig                  |   13 -
>  drivers/tty/Makefile                  |    1 -
>  drivers/tty/n_r3964.c                 | 1283 -------------------------
>  drivers/tty/vt/vt.c                   |    2 -
>  include/linux/n_r3964.h               |  175 ----
>  include/uapi/linux/n_r3964.h          |   99 --
>  7 files changed, 1574 deletions(-)
>  delete mode 100644 drivers/tty/n_r3964.c
>  delete mode 100644 include/linux/n_r3964.h
>  delete mode 100644 include/uapi/linux/n_r3964.h

Oh yes, thank you!  I guess no one really cares about this anymore,
thanks for removing it.

greg k-h

Patch
diff mbox series

diff --git a/arch/powerpc/configs/ppc6xx_defconfig b/arch/powerpc/configs/ppc6xx_defconfig
index 1fd9d1260f9e..ee09f7bb6ea9 100644
--- a/arch/powerpc/configs/ppc6xx_defconfig
+++ b/arch/powerpc/configs/ppc6xx_defconfig
@@ -621,7 +621,6 @@  CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_VIRTIO=m
 CONFIG_NVRAM=y
 CONFIG_DTLK=m
-CONFIG_R3964=m
 CONFIG_CARDMAN_4000=m
 CONFIG_CARDMAN_4040=m
 CONFIG_IPWIRELESS=m
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index b151e0fcdeb5..52d0dd49a683 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -218,19 +218,6 @@  config XILINX_HWICAP
 
 	  If unsure, say N.
 
-config R3964
-	tristate "Siemens R3964 line discipline"
-	depends on TTY && BROKEN
-	help
-	  This driver allows synchronous communication with devices using the
-	  Siemens R3964 packet protocol. Unless you are dealing with special
-	  hardware like PLCs, you are unlikely to need this.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called n_r3964.
-
-	  If unsure, say N.
-
 config APPLICOM
 	tristate "Applicom intelligent fieldbus card support"
 	depends on PCI
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index c7054f5117c3..a2bd75fbaaa4 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -9,7 +9,6 @@  obj-$(CONFIG_AUDIT)		+= tty_audit.o
 obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
 obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
 obj-$(CONFIG_N_GSM)		+= n_gsm.o
-obj-$(CONFIG_R3964)		+= n_r3964.o
 
 obj-y				+= vt/
 obj-$(CONFIG_HVC_DRIVER)	+= hvc/
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
deleted file mode 100644
index 2eb76ea1d88d..000000000000
--- a/drivers/tty/n_r3964.c
+++ /dev/null
@@ -1,1283 +0,0 @@ 
-// SPDX-License-Identifier: GPL-1.0+
-/* r3964 linediscipline for linux
- *
- * -----------------------------------------------------------
- * Copyright by 
- * Philips Automation Projects
- * Kassel (Germany)
- * -----------------------------------------------------------
- * Author:
- * L. Haag
- *
- * $Log: n_r3964.c,v $
- * Revision 1.10  2001/03/18 13:02:24  dwmw2
- * Fix timer usage, use spinlocks properly.
- *
- * Revision 1.9  2001/03/18 12:52:14  dwmw2
- * Merge changes in 2.4.2
- *
- * Revision 1.8  2000/03/23 14:14:54  dwmw2
- * Fix race in sleeping in r3964_read()
- *
- * Revision 1.7  1999/28/08 11:41:50  dwmw2
- * Port to 2.3 kernel
- *
- * Revision 1.6  1998/09/30 00:40:40  dwmw2
- * Fixed compilation on 2.0.x kernels
- * Updated to newly registered tty-ldisc number 9
- *
- * Revision 1.5  1998/09/04 21:57:36  dwmw2
- * Signal handling bug fixes, port to 2.1.x.
- *
- * Revision 1.4  1998/04/02 20:26:59  lhaag
- * select, blocking, ...
- *
- * Revision 1.3  1998/02/12 18:58:43  root
- * fixed some memory leaks
- * calculation of checksum characters
- *
- * Revision 1.2  1998/02/07 13:03:34  root
- * ioctl read_telegram
- *
- * Revision 1.1  1998/02/06 19:21:03  root
- * Initial revision
- *
- *
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/types.h>
-#include <linux/fcntl.h>
-#include <linux/interrupt.h>
-#include <linux/ptrace.h>
-#include <linux/ioport.h>
-#include <linux/in.h>
-#include <linux/slab.h>
-#include <linux/tty.h>
-#include <linux/errno.h>
-#include <linux/string.h>	/* used in new tty drivers */
-#include <linux/signal.h>	/* used in new tty drivers */
-#include <linux/ioctl.h>
-#include <linux/n_r3964.h>
-#include <linux/poll.h>
-#include <linux/init.h>
-#include <linux/uaccess.h>
-
-/*#define DEBUG_QUEUE*/
-
-/* Log successful handshake and protocol operations  */
-/*#define DEBUG_PROTO_S*/
-
-/* Log handshake and protocol errors: */
-/*#define DEBUG_PROTO_E*/
-
-/* Log Linediscipline operations (open, close, read, write...): */
-/*#define DEBUG_LDISC*/
-
-/* Log module and memory operations (init, cleanup; kmalloc, kfree): */
-/*#define DEBUG_MODUL*/
-
-/* Macro helpers for debug output: */
-#define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
-
-#ifdef DEBUG_MODUL
-#define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_M(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_PROTO_S
-#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_PS(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_PROTO_E
-#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_PE(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_LDISC
-#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_L(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_QUEUE
-#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_Q(fmt, arg...) do {} while (0)
-#endif
-static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
-static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
-static void put_char(struct r3964_info *pInfo, unsigned char ch);
-static void trigger_transmit(struct r3964_info *pInfo);
-static void retry_transmit(struct r3964_info *pInfo);
-static void transmit_block(struct r3964_info *pInfo);
-static void receive_char(struct r3964_info *pInfo, const unsigned char c);
-static void receive_error(struct r3964_info *pInfo, const char flag);
-static void on_timeout(struct timer_list *t);
-static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
-static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
-		unsigned char __user * buf);
-static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
-		int error_code, struct r3964_block_header *pBlock);
-static struct r3964_message *remove_msg(struct r3964_info *pInfo,
-		struct r3964_client_info *pClient);
-static void remove_client_block(struct r3964_info *pInfo,
-		struct r3964_client_info *pClient);
-
-static int r3964_open(struct tty_struct *tty);
-static void r3964_close(struct tty_struct *tty);
-static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
-		void *cookie, unsigned char *buf, size_t nr);
-static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
-		const unsigned char *buf, size_t nr);
-static int r3964_ioctl(struct tty_struct *tty, struct file *file,
-		unsigned int cmd, unsigned long arg);
-#ifdef CONFIG_COMPAT
-static int r3964_compat_ioctl(struct tty_struct *tty, struct file *file,
-		unsigned int cmd, unsigned long arg);
-#endif
-static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
-static __poll_t r3964_poll(struct tty_struct *tty, struct file *file,
-		struct poll_table_struct *wait);
-static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-		char *fp, int count);
-
-static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
-	.owner = THIS_MODULE,
-	.name = "R3964",
-	.open = r3964_open,
-	.close = r3964_close,
-	.read = r3964_read,
-	.write = r3964_write,
-	.ioctl = r3964_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl = r3964_compat_ioctl,
-#endif
-	.set_termios = r3964_set_termios,
-	.poll = r3964_poll,
-	.receive_buf = r3964_receive_buf,
-};
-
-static void dump_block(const unsigned char *block, unsigned int length)
-{
-	unsigned int i, j;
-	char linebuf[16 * 3 + 1];
-
-	for (i = 0; i < length; i += 16) {
-		for (j = 0; (j < 16) && (j + i < length); j++) {
-			sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
-		}
-		linebuf[3 * j] = '\0';
-		TRACE_PS("%s", linebuf);
-	}
-}
-
-/*************************************************************
- * Driver initialisation
- *************************************************************/
-
-/*************************************************************
- * Module support routines
- *************************************************************/
-
-static void __exit r3964_exit(void)
-{
-	int status;
-
-	TRACE_M("cleanup_module()");
-
-	status = tty_unregister_ldisc(N_R3964);
-
-	if (status != 0) {
-		printk(KERN_ERR "r3964: error unregistering linediscipline: "
-				"%d\n", status);
-	} else {
-		TRACE_L("linediscipline successfully unregistered");
-	}
-}
-
-static int __init r3964_init(void)
-{
-	int status;
-
-	printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
-
-	/*
-	 * Register the tty line discipline
-	 */
-
-	status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
-	if (status == 0) {
-		TRACE_L("line discipline %d registered", N_R3964);
-		TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
-			tty_ldisc_N_R3964.num);
-		TRACE_L("open=%p", tty_ldisc_N_R3964.open);
-		TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
-	} else {
-		printk(KERN_ERR "r3964: error registering line discipline: "
-				"%d\n", status);
-	}
-	return status;
-}
-
-module_init(r3964_init);
-module_exit(r3964_exit);
-
-/*************************************************************
- * Protocol implementation routines
- *************************************************************/
-
-static void add_tx_queue(struct r3964_info *pInfo,
-			 struct r3964_block_header *pHeader)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&pInfo->lock, flags);
-
-	pHeader->next = NULL;
-
-	if (pInfo->tx_last == NULL) {
-		pInfo->tx_first = pInfo->tx_last = pHeader;
-	} else {
-		pInfo->tx_last->next = pHeader;
-		pInfo->tx_last = pHeader;
-	}
-
-	spin_unlock_irqrestore(&pInfo->lock, flags);
-
-	TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
-		pHeader, pHeader->length, pInfo->tx_first);
-}
-
-static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
-{
-	struct r3964_block_header *pHeader;
-	unsigned long flags;
-#ifdef DEBUG_QUEUE
-	struct r3964_block_header *pDump;
-#endif
-
-	pHeader = pInfo->tx_first;
-
-	if (pHeader == NULL)
-		return;
-
-#ifdef DEBUG_QUEUE
-	printk("r3964: remove_from_tx_queue: %p, length %u - ",
-		pHeader, pHeader->length);
-	for (pDump = pHeader; pDump; pDump = pDump->next)
-		printk("%p ", pDump);
-	printk("\n");
-#endif
-
-	if (pHeader->owner) {
-		if (error_code) {
-			add_msg(pHeader->owner, R3964_MSG_ACK, 0,
-				error_code, NULL);
-		} else {
-			add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
-				error_code, NULL);
-		}
-		wake_up_interruptible(&pInfo->tty->read_wait);
-	}
-
-	spin_lock_irqsave(&pInfo->lock, flags);
-
-	pInfo->tx_first = pHeader->next;
-	if (pInfo->tx_first == NULL) {
-		pInfo->tx_last = NULL;
-	}
-
-	spin_unlock_irqrestore(&pInfo->lock, flags);
-
-	kfree(pHeader);
-	TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
-
-	TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
-		pInfo->tx_first, pInfo->tx_last);
-}
-
-static void add_rx_queue(struct r3964_info *pInfo,
-			 struct r3964_block_header *pHeader)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&pInfo->lock, flags);
-
-	pHeader->next = NULL;
-
-	if (pInfo->rx_last == NULL) {
-		pInfo->rx_first = pInfo->rx_last = pHeader;
-	} else {
-		pInfo->rx_last->next = pHeader;
-		pInfo->rx_last = pHeader;
-	}
-	pInfo->blocks_in_rx_queue++;
-
-	spin_unlock_irqrestore(&pInfo->lock, flags);
-
-	TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
-		pHeader, pHeader->length,
-		pInfo->rx_first, pInfo->blocks_in_rx_queue);
-}
-
-static void remove_from_rx_queue(struct r3964_info *pInfo,
-				 struct r3964_block_header *pHeader)
-{
-	unsigned long flags;
-	struct r3964_block_header *pFind;
-
-	if (pHeader == NULL)
-		return;
-
-	TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
-		pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
-	TRACE_Q("remove_from_rx_queue: %p, length %u",
-		pHeader, pHeader->length);
-
-	spin_lock_irqsave(&pInfo->lock, flags);
-
-	if (pInfo->rx_first == pHeader) {
-		/* Remove the first block in the linked list: */
-		pInfo->rx_first = pHeader->next;
-
-		if (pInfo->rx_first == NULL) {
-			pInfo->rx_last = NULL;
-		}
-		pInfo->blocks_in_rx_queue--;
-	} else {
-		/* Find block to remove: */
-		for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
-			if (pFind->next == pHeader) {
-				/* Got it. */
-				pFind->next = pHeader->next;
-				pInfo->blocks_in_rx_queue--;
-				if (pFind->next == NULL) {
-					/* Oh, removed the last one! */
-					pInfo->rx_last = pFind;
-				}
-				break;
-			}
-		}
-	}
-
-	spin_unlock_irqrestore(&pInfo->lock, flags);
-
-	kfree(pHeader);
-	TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
-
-	TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
-		pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
-}
-
-static void put_char(struct r3964_info *pInfo, unsigned char ch)
-{
-	struct tty_struct *tty = pInfo->tty;
-	/* FIXME: put_char should not be called from an IRQ */
-	tty_put_char(tty, ch);
-	pInfo->bcc ^= ch;
-}
-
-static void flush(struct r3964_info *pInfo)
-{
-	struct tty_struct *tty = pInfo->tty;
-
-	if (tty == NULL || tty->ops->flush_chars == NULL)
-		return;
-	tty->ops->flush_chars(tty);
-}
-
-static void trigger_transmit(struct r3964_info *pInfo)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&pInfo->lock, flags);
-
-	if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
-		pInfo->state = R3964_TX_REQUEST;
-		pInfo->nRetry = 0;
-		pInfo->flags &= ~R3964_ERROR;
-		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
-
-		spin_unlock_irqrestore(&pInfo->lock, flags);
-
-		TRACE_PS("trigger_transmit - sent STX");
-
-		put_char(pInfo, STX);
-		flush(pInfo);
-
-		pInfo->bcc = 0;
-	} else {
-		spin_unlock_irqrestore(&pInfo->lock, flags);
-	}
-}
-
-static void retry_transmit(struct r3964_info *pInfo)
-{
-	if (pInfo->nRetry < R3964_MAX_RETRIES) {
-		TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
-		pInfo->bcc = 0;
-		put_char(pInfo, STX);
-		flush(pInfo);
-		pInfo->state = R3964_TX_REQUEST;
-		pInfo->nRetry++;
-		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
-	} else {
-		TRACE_PE("transmission failed after %d retries",
-			 R3964_MAX_RETRIES);
-
-		remove_from_tx_queue(pInfo, R3964_TX_FAIL);
-
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		pInfo->state = R3964_IDLE;
-
-		trigger_transmit(pInfo);
-	}
-}
-
-static void transmit_block(struct r3964_info *pInfo)
-{
-	struct tty_struct *tty = pInfo->tty;
-	struct r3964_block_header *pBlock = pInfo->tx_first;
-	int room = 0;
-
-	if (tty == NULL || pBlock == NULL) {
-		return;
-	}
-
-	room = tty_write_room(tty);
-
-	TRACE_PS("transmit_block %p, room %d, length %d",
-		 pBlock, room, pBlock->length);
-
-	while (pInfo->tx_position < pBlock->length) {
-		if (room < 2)
-			break;
-
-		if (pBlock->data[pInfo->tx_position] == DLE) {
-			/* send additional DLE char: */
-			put_char(pInfo, DLE);
-		}
-		put_char(pInfo, pBlock->data[pInfo->tx_position++]);
-
-		room--;
-	}
-
-	if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
-		put_char(pInfo, DLE);
-		put_char(pInfo, ETX);
-		if (pInfo->flags & R3964_BCC) {
-			put_char(pInfo, pInfo->bcc);
-		}
-		pInfo->state = R3964_WAIT_FOR_TX_ACK;
-		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
-	}
-	flush(pInfo);
-}
-
-static void on_receive_block(struct r3964_info *pInfo)
-{
-	unsigned int length;
-	struct r3964_client_info *pClient;
-	struct r3964_block_header *pBlock;
-
-	length = pInfo->rx_position;
-
-	/* compare byte checksum characters: */
-	if (pInfo->flags & R3964_BCC) {
-		if (pInfo->bcc != pInfo->last_rx) {
-			TRACE_PE("checksum error - got %x but expected %x",
-				 pInfo->last_rx, pInfo->bcc);
-			pInfo->flags |= R3964_CHECKSUM;
-		}
-	}
-
-	/* check for errors (parity, overrun,...): */
-	if (pInfo->flags & R3964_ERROR) {
-		TRACE_PE("on_receive_block - transmission failed error %x",
-			 pInfo->flags & R3964_ERROR);
-
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		if (pInfo->nRetry < R3964_MAX_RETRIES) {
-			pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
-			pInfo->nRetry++;
-			mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
-		} else {
-			TRACE_PE("on_receive_block - failed after max retries");
-			pInfo->state = R3964_IDLE;
-		}
-		return;
-	}
-
-	/* received block; submit DLE: */
-	put_char(pInfo, DLE);
-	flush(pInfo);
-	del_timer_sync(&pInfo->tmr);
-	TRACE_PS(" rx success: got %d chars", length);
-
-	/* prepare struct r3964_block_header: */
-	pBlock = kmalloc(length + sizeof(struct r3964_block_header),
-			GFP_KERNEL);
-	TRACE_M("on_receive_block - kmalloc %p", pBlock);
-
-	if (pBlock == NULL)
-		return;
-
-	pBlock->length = length;
-	pBlock->data = ((unsigned char *)pBlock) +
-			sizeof(struct r3964_block_header);
-	pBlock->locks = 0;
-	pBlock->next = NULL;
-	pBlock->owner = NULL;
-
-	memcpy(pBlock->data, pInfo->rx_buf, length);
-
-	/* queue block into rx_queue: */
-	add_rx_queue(pInfo, pBlock);
-
-	/* notify attached client processes: */
-	for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
-		if (pClient->sig_flags & R3964_SIG_DATA) {
-			add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
-				pBlock);
-		}
-	}
-	wake_up_interruptible(&pInfo->tty->read_wait);
-
-	pInfo->state = R3964_IDLE;
-
-	trigger_transmit(pInfo);
-}
-
-static void receive_char(struct r3964_info *pInfo, const unsigned char c)
-{
-	switch (pInfo->state) {
-	case R3964_TX_REQUEST:
-		if (c == DLE) {
-			TRACE_PS("TX_REQUEST - got DLE");
-
-			pInfo->state = R3964_TRANSMITTING;
-			pInfo->tx_position = 0;
-
-			transmit_block(pInfo);
-		} else if (c == STX) {
-			if (pInfo->nRetry == 0) {
-				TRACE_PE("TX_REQUEST - init conflict");
-				if (pInfo->priority == R3964_SLAVE) {
-					goto start_receiving;
-				}
-			} else {
-				TRACE_PE("TX_REQUEST - secondary init "
-					"conflict!? Switching to SLAVE mode "
-					"for next rx.");
-				goto start_receiving;
-			}
-		} else {
-			TRACE_PE("TX_REQUEST - char != DLE: %x", c);
-			retry_transmit(pInfo);
-		}
-		break;
-	case R3964_TRANSMITTING:
-		if (c == NAK) {
-			TRACE_PE("TRANSMITTING - got NAK");
-			retry_transmit(pInfo);
-		} else {
-			TRACE_PE("TRANSMITTING - got invalid char");
-
-			pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
-			mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
-		}
-		break;
-	case R3964_WAIT_FOR_TX_ACK:
-		if (c == DLE) {
-			TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
-			remove_from_tx_queue(pInfo, R3964_OK);
-
-			pInfo->state = R3964_IDLE;
-			trigger_transmit(pInfo);
-		} else {
-			retry_transmit(pInfo);
-		}
-		break;
-	case R3964_WAIT_FOR_RX_REPEAT:
-	case R3964_IDLE:
-		if (c == STX) {
-			/* Prevent rx_queue from overflow: */
-			if (pInfo->blocks_in_rx_queue >=
-			    R3964_MAX_BLOCKS_IN_RX_QUEUE) {
-				TRACE_PE("IDLE - got STX but no space in "
-						"rx_queue!");
-				pInfo->state = R3964_WAIT_FOR_RX_BUF;
-				mod_timer(&pInfo->tmr,
-					  jiffies + R3964_TO_NO_BUF);
-				break;
-			}
-start_receiving:
-			/* Ok, start receiving: */
-			TRACE_PS("IDLE - got STX");
-			pInfo->rx_position = 0;
-			pInfo->last_rx = 0;
-			pInfo->flags &= ~R3964_ERROR;
-			pInfo->state = R3964_RECEIVING;
-			mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
-			pInfo->nRetry = 0;
-			put_char(pInfo, DLE);
-			flush(pInfo);
-			pInfo->bcc = 0;
-		}
-		break;
-	case R3964_RECEIVING:
-		if (pInfo->rx_position < RX_BUF_SIZE) {
-			pInfo->bcc ^= c;
-
-			if (c == DLE) {
-				if (pInfo->last_rx == DLE) {
-					pInfo->last_rx = 0;
-					goto char_to_buf;
-				}
-				pInfo->last_rx = DLE;
-				break;
-			} else if ((c == ETX) && (pInfo->last_rx == DLE)) {
-				if (pInfo->flags & R3964_BCC) {
-					pInfo->state = R3964_WAIT_FOR_BCC;
-					mod_timer(&pInfo->tmr,
-						  jiffies + R3964_TO_ZVZ);
-				} else {
-					on_receive_block(pInfo);
-				}
-			} else {
-				pInfo->last_rx = c;
-char_to_buf:
-				pInfo->rx_buf[pInfo->rx_position++] = c;
-				mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
-			}
-		}
-		/* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
-		break;
-	case R3964_WAIT_FOR_BCC:
-		pInfo->last_rx = c;
-		on_receive_block(pInfo);
-		break;
-	}
-}
-
-static void receive_error(struct r3964_info *pInfo, const char flag)
-{
-	switch (flag) {
-	case TTY_NORMAL:
-		break;
-	case TTY_BREAK:
-		TRACE_PE("received break");
-		pInfo->flags |= R3964_BREAK;
-		break;
-	case TTY_PARITY:
-		TRACE_PE("parity error");
-		pInfo->flags |= R3964_PARITY;
-		break;
-	case TTY_FRAME:
-		TRACE_PE("frame error");
-		pInfo->flags |= R3964_FRAME;
-		break;
-	case TTY_OVERRUN:
-		TRACE_PE("frame overrun");
-		pInfo->flags |= R3964_OVERRUN;
-		break;
-	default:
-		TRACE_PE("receive_error - unknown flag %d", flag);
-		pInfo->flags |= R3964_UNKNOWN;
-		break;
-	}
-}
-
-static void on_timeout(struct timer_list *t)
-{
-	struct r3964_info *pInfo = from_timer(pInfo, t, tmr);
-
-	switch (pInfo->state) {
-	case R3964_TX_REQUEST:
-		TRACE_PE("TX_REQUEST - timeout");
-		retry_transmit(pInfo);
-		break;
-	case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		retry_transmit(pInfo);
-		break;
-	case R3964_WAIT_FOR_TX_ACK:
-		TRACE_PE("WAIT_FOR_TX_ACK - timeout");
-		retry_transmit(pInfo);
-		break;
-	case R3964_WAIT_FOR_RX_BUF:
-		TRACE_PE("WAIT_FOR_RX_BUF - timeout");
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		pInfo->state = R3964_IDLE;
-		break;
-	case R3964_RECEIVING:
-		TRACE_PE("RECEIVING - timeout after %d chars",
-			 pInfo->rx_position);
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		pInfo->state = R3964_IDLE;
-		break;
-	case R3964_WAIT_FOR_RX_REPEAT:
-		TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
-		pInfo->state = R3964_IDLE;
-		break;
-	case R3964_WAIT_FOR_BCC:
-		TRACE_PE("WAIT_FOR_BCC - timeout");
-		put_char(pInfo, NAK);
-		flush(pInfo);
-		pInfo->state = R3964_IDLE;
-		break;
-	}
-}
-
-static struct r3964_client_info *findClient(struct r3964_info *pInfo,
-		struct pid *pid)
-{
-	struct r3964_client_info *pClient;
-
-	for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
-		if (pClient->pid == pid) {
-			return pClient;
-		}
-	}
-	return NULL;
-}
-
-static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
-{
-	struct r3964_client_info *pClient;
-	struct r3964_client_info **ppClient;
-	struct r3964_message *pMsg;
-
-	if ((arg & R3964_SIG_ALL) == 0) {
-		/* Remove client from client list */
-		for (ppClient = &pInfo->firstClient; *ppClient;
-		     ppClient = &(*ppClient)->next) {
-			pClient = *ppClient;
-
-			if (pClient->pid == pid) {
-				TRACE_PS("removing client %d from client list",
-					 pid_nr(pid));
-				*ppClient = pClient->next;
-				while (pClient->msg_count) {
-					pMsg = remove_msg(pInfo, pClient);
-					if (pMsg) {
-						kfree(pMsg);
-						TRACE_M("enable_signals - msg "
-							"kfree %p", pMsg);
-					}
-				}
-				put_pid(pClient->pid);
-				kfree(pClient);
-				TRACE_M("enable_signals - kfree %p", pClient);
-				return 0;
-			}
-		}
-		return -EINVAL;
-	} else {
-		pClient = findClient(pInfo, pid);
-		if (pClient) {
-			/* update signal options */
-			pClient->sig_flags = arg;
-		} else {
-			/* add client to client list */
-			pClient = kmalloc(sizeof(struct r3964_client_info),
-					GFP_KERNEL);
-			TRACE_M("enable_signals - kmalloc %p", pClient);
-			if (pClient == NULL)
-				return -ENOMEM;
-
-			TRACE_PS("add client %d to client list", pid_nr(pid));
-			spin_lock_init(&pClient->lock);
-			pClient->sig_flags = arg;
-			pClient->pid = get_pid(pid);
-			pClient->next = pInfo->firstClient;
-			pClient->first_msg = NULL;
-			pClient->last_msg = NULL;
-			pClient->next_block_to_read = NULL;
-			pClient->msg_count = 0;
-			pInfo->firstClient = pClient;
-		}
-	}
-
-	return 0;
-}
-
-static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
-			 unsigned char __user * buf)
-{
-	struct r3964_client_info *pClient;
-	struct r3964_block_header *block;
-
-	if (!buf) {
-		return -EINVAL;
-	}
-
-	pClient = findClient(pInfo, pid);
-	if (pClient == NULL) {
-		return -EINVAL;
-	}
-
-	block = pClient->next_block_to_read;
-	if (!block) {
-		return 0;
-	} else {
-		if (copy_to_user(buf, block->data, block->length))
-			return -EFAULT;
-
-		remove_client_block(pInfo, pClient);
-		return block->length;
-	}
-
-	return -EINVAL;
-}
-
-static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
-		int error_code, struct r3964_block_header *pBlock)
-{
-	struct r3964_message *pMsg;
-	unsigned long flags;
-
-	if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
-queue_the_message:
-
-		pMsg = kmalloc(sizeof(struct r3964_message),
-				error_code ? GFP_ATOMIC : GFP_KERNEL);
-		TRACE_M("add_msg - kmalloc %p", pMsg);
-		if (pMsg == NULL) {
-			return;
-		}
-
-		spin_lock_irqsave(&pClient->lock, flags);
-
-		pMsg->msg_id = msg_id;
-		pMsg->arg = arg;
-		pMsg->error_code = error_code;
-		pMsg->block = pBlock;
-		pMsg->next = NULL;
-
-		if (pClient->last_msg == NULL) {
-			pClient->first_msg = pClient->last_msg = pMsg;
-		} else {
-			pClient->last_msg->next = pMsg;
-			pClient->last_msg = pMsg;
-		}
-
-		pClient->msg_count++;
-
-		if (pBlock != NULL) {
-			pBlock->locks++;
-		}
-		spin_unlock_irqrestore(&pClient->lock, flags);
-	} else {
-		if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
-		    && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
-			pClient->last_msg->arg++;
-			TRACE_PE("add_msg - inc prev OVERFLOW-msg");
-		} else {
-			msg_id = R3964_MSG_ACK;
-			arg = 0;
-			error_code = R3964_OVERFLOW;
-			pBlock = NULL;
-			TRACE_PE("add_msg - queue OVERFLOW-msg");
-			goto queue_the_message;
-		}
-	}
-	/* Send SIGIO signal to client process: */
-	if (pClient->sig_flags & R3964_USE_SIGIO) {
-		kill_pid(pClient->pid, SIGIO, 1);
-	}
-}
-
-static struct r3964_message *remove_msg(struct r3964_info *pInfo,
-					struct r3964_client_info *pClient)
-{
-	struct r3964_message *pMsg = NULL;
-	unsigned long flags;
-
-	if (pClient->first_msg) {
-		spin_lock_irqsave(&pClient->lock, flags);
-
-		pMsg = pClient->first_msg;
-		pClient->first_msg = pMsg->next;
-		if (pClient->first_msg == NULL) {
-			pClient->last_msg = NULL;
-		}
-
-		pClient->msg_count--;
-		if (pMsg->block) {
-			remove_client_block(pInfo, pClient);
-			pClient->next_block_to_read = pMsg->block;
-		}
-		spin_unlock_irqrestore(&pClient->lock, flags);
-	}
-	return pMsg;
-}
-
-static void remove_client_block(struct r3964_info *pInfo,
-				struct r3964_client_info *pClient)
-{
-	struct r3964_block_header *block;
-
-	TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
-
-	block = pClient->next_block_to_read;
-	if (block) {
-		block->locks--;
-		if (block->locks == 0) {
-			remove_from_rx_queue(pInfo, block);
-		}
-	}
-	pClient->next_block_to_read = NULL;
-}
-
-/*************************************************************
- * Line discipline routines
- *************************************************************/
-
-static int r3964_open(struct tty_struct *tty)
-{
-	struct r3964_info *pInfo;
-
-	TRACE_L("open");
-	TRACE_L("tty=%p, PID=%d, disc_data=%p",
-		tty, current->pid, tty->disc_data);
-
-	pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
-	TRACE_M("r3964_open - info kmalloc %p", pInfo);
-
-	if (!pInfo) {
-		printk(KERN_ERR "r3964: failed to alloc info structure\n");
-		return -ENOMEM;
-	}
-
-	pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
-	TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
-
-	if (!pInfo->rx_buf) {
-		printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
-		kfree(pInfo);
-		TRACE_M("r3964_open - info kfree %p", pInfo);
-		return -ENOMEM;
-	}
-
-	pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
-	TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
-
-	if (!pInfo->tx_buf) {
-		printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
-		kfree(pInfo->rx_buf);
-		TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
-		kfree(pInfo);
-		TRACE_M("r3964_open - info kfree %p", pInfo);
-		return -ENOMEM;
-	}
-
-	spin_lock_init(&pInfo->lock);
-	mutex_init(&pInfo->read_lock);
-	pInfo->tty = tty;
-	pInfo->priority = R3964_MASTER;
-	pInfo->rx_first = pInfo->rx_last = NULL;
-	pInfo->tx_first = pInfo->tx_last = NULL;
-	pInfo->rx_position = 0;
-	pInfo->tx_position = 0;
-	pInfo->last_rx = 0;
-	pInfo->blocks_in_rx_queue = 0;
-	pInfo->firstClient = NULL;
-	pInfo->state = R3964_IDLE;
-	pInfo->flags = R3964_DEBUG;
-	pInfo->nRetry = 0;
-
-	tty->disc_data = pInfo;
-	tty->receive_room = 65536;
-
-	timer_setup(&pInfo->tmr, on_timeout, 0);
-
-	return 0;
-}
-
-static void r3964_close(struct tty_struct *tty)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	struct r3964_client_info *pClient, *pNext;
-	struct r3964_message *pMsg;
-	struct r3964_block_header *pHeader, *pNextHeader;
-	unsigned long flags;
-
-	TRACE_L("close");
-
-	/*
-	 * Make sure that our task queue isn't activated.  If it
-	 * is, take it out of the linked list.
-	 */
-	del_timer_sync(&pInfo->tmr);
-
-	/* Remove client-structs and message queues: */
-	pClient = pInfo->firstClient;
-	while (pClient) {
-		pNext = pClient->next;
-		while (pClient->msg_count) {
-			pMsg = remove_msg(pInfo, pClient);
-			if (pMsg) {
-				kfree(pMsg);
-				TRACE_M("r3964_close - msg kfree %p", pMsg);
-			}
-		}
-		put_pid(pClient->pid);
-		kfree(pClient);
-		TRACE_M("r3964_close - client kfree %p", pClient);
-		pClient = pNext;
-	}
-	/* Remove jobs from tx_queue: */
-	spin_lock_irqsave(&pInfo->lock, flags);
-	pHeader = pInfo->tx_first;
-	pInfo->tx_first = pInfo->tx_last = NULL;
-	spin_unlock_irqrestore(&pInfo->lock, flags);
-
-	while (pHeader) {
-		pNextHeader = pHeader->next;
-		kfree(pHeader);
-		pHeader = pNextHeader;
-	}
-
-	/* Free buffers: */
-	kfree(pInfo->rx_buf);
-	TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
-	kfree(pInfo->tx_buf);
-	TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
-	kfree(pInfo);
-	TRACE_M("r3964_close - info kfree %p", pInfo);
-}
-
-static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
-			  unsigned char *kbuf, size_t nr,
-			  void **cookie, unsigned long offset)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	struct r3964_client_info *pClient;
-	struct r3964_message *pMsg;
-	struct r3964_client_message theMsg;
-	int ret;
-
-	TRACE_L("read()");
-
-	/*
-	 *	Internal serialization of reads.
-	 */
-	if (file->f_flags & O_NONBLOCK) {
-		if (!mutex_trylock(&pInfo->read_lock))
-			return -EAGAIN;
-	} else {
-		if (mutex_lock_interruptible(&pInfo->read_lock))
-			return -ERESTARTSYS;
-	}
-
-	pClient = findClient(pInfo, task_pid(current));
-	if (pClient) {
-		pMsg = remove_msg(pInfo, pClient);
-		if (pMsg == NULL) {
-			/* no messages available. */
-			if (tty_io_nonblock(tty, file)) {
-				ret = -EAGAIN;
-				goto unlock;
-			}
-			/* block until there is a message: */
-			wait_event_interruptible(tty->read_wait,
-					(pMsg = remove_msg(pInfo, pClient)));
-		}
-
-		/* If we still haven't got a message, we must have been signalled */
-
-		if (!pMsg) {
-			ret = -EINTR;
-			goto unlock;
-		}
-
-		/* deliver msg to client process: */
-		theMsg.msg_id = pMsg->msg_id;
-		theMsg.arg = pMsg->arg;
-		theMsg.error_code = pMsg->error_code;
-		ret = sizeof(struct r3964_client_message);
-
-		kfree(pMsg);
-		TRACE_M("r3964_read - msg kfree %p", pMsg);
-
-		memcpy(kbuf, &theMsg, ret);
-
-		TRACE_PS("read - return %d", ret);
-		goto unlock;
-	}
-	ret = -EPERM;
-unlock:
-	mutex_unlock(&pInfo->read_lock);
-	return ret;
-}
-
-static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
-			   const unsigned char *data, size_t count)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	struct r3964_block_header *pHeader;
-	struct r3964_client_info *pClient;
-	unsigned char *new_data;
-
-	TRACE_L("write request, %d characters", count);
-/* 
- * Verify the pointers 
- */
-
-	if (!pInfo)
-		return -EIO;
-
-/*
- * Ensure that the caller does not wish to send too much.
- */
-	if (count > R3964_MTU) {
-		if (pInfo->flags & R3964_DEBUG) {
-			TRACE_L(KERN_WARNING "r3964_write: truncating user "
-				"packet from %u to mtu %d", count, R3964_MTU);
-		}
-		count = R3964_MTU;
-	}
-/*
- * Allocate a buffer for the data and copy it from the buffer with header prepended
- */
-	new_data = kmalloc(count + sizeof(struct r3964_block_header),
-			GFP_KERNEL);
-	TRACE_M("r3964_write - kmalloc %p", new_data);
-	if (new_data == NULL) {
-		if (pInfo->flags & R3964_DEBUG) {
-			printk(KERN_ERR "r3964_write: no memory\n");
-		}
-		return -ENOSPC;
-	}
-
-	pHeader = (struct r3964_block_header *)new_data;
-	pHeader->data = new_data + sizeof(struct r3964_block_header);
-	pHeader->length = count;
-	pHeader->locks = 0;
-	pHeader->owner = NULL;
-
-	pClient = findClient(pInfo, task_pid(current));
-	if (pClient) {
-		pHeader->owner = pClient;
-	}
-
-	memcpy(pHeader->data, data, count);	/* We already verified this */
-
-	if (pInfo->flags & R3964_DEBUG) {
-		dump_block(pHeader->data, count);
-	}
-
-/*
- * Add buffer to transmit-queue:
- */
-	add_tx_queue(pInfo, pHeader);
-	trigger_transmit(pInfo);
-
-	return 0;
-}
-
-static int r3964_ioctl(struct tty_struct *tty, struct file *file,
-		unsigned int cmd, unsigned long arg)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	if (pInfo == NULL)
-		return -EINVAL;
-	switch (cmd) {
-	case R3964_ENABLE_SIGNALS:
-		return enable_signals(pInfo, task_pid(current), arg);
-	case R3964_SETPRIORITY:
-		if (arg < R3964_MASTER || arg > R3964_SLAVE)
-			return -EINVAL;
-		pInfo->priority = arg & 0xff;
-		return 0;
-	case R3964_USE_BCC:
-		if (arg)
-			pInfo->flags |= R3964_BCC;
-		else
-			pInfo->flags &= ~R3964_BCC;
-		return 0;
-	case R3964_READ_TELEGRAM:
-		return read_telegram(pInfo, task_pid(current),
-				(unsigned char __user *)arg);
-	default:
-		return -ENOIOCTLCMD;
-	}
-}
-
-#ifdef CONFIG_COMPAT
-static int r3964_compat_ioctl(struct tty_struct *tty, struct file *file,
-		unsigned int cmd, unsigned long arg)
-{
-	switch (cmd) {
-	case R3964_ENABLE_SIGNALS:
-	case R3964_SETPRIORITY:
-	case R3964_USE_BCC:
-		return r3964_ioctl(tty, file, cmd, arg);
-	default:
-		return -ENOIOCTLCMD;
-	}
-}
-#endif
-
-static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
-{
-	TRACE_L("set_termios");
-}
-
-/* Called without the kernel lock held - fine */
-static __poll_t r3964_poll(struct tty_struct *tty, struct file *file,
-			struct poll_table_struct *wait)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	struct r3964_client_info *pClient;
-	struct r3964_message *pMsg = NULL;
-	unsigned long flags;
-	__poll_t result = EPOLLOUT;
-
-	TRACE_L("POLL");
-
-	pClient = findClient(pInfo, task_pid(current));
-	if (pClient) {
-		poll_wait(file, &tty->read_wait, wait);
-		spin_lock_irqsave(&pInfo->lock, flags);
-		pMsg = pClient->first_msg;
-		spin_unlock_irqrestore(&pInfo->lock, flags);
-		if (pMsg)
-			result |= EPOLLIN | EPOLLRDNORM;
-	} else {
-		result = -EINVAL;
-	}
-	return result;
-}
-
-static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-			char *fp, int count)
-{
-	struct r3964_info *pInfo = tty->disc_data;
-	const unsigned char *p;
-	char *f, flags = TTY_NORMAL;
-	int i;
-
-	for (i = count, p = cp, f = fp; i; i--, p++) {
-		if (f)
-			flags = *f++;
-		if (flags == TTY_NORMAL) {
-			receive_char(pInfo, *p);
-		} else {
-			receive_error(pInfo, flags);
-		}
-
-	}
-}
-
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_LDISC(N_R3964);
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 01645e87b3d5..e5040bdadcd6 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3260,8 +3260,6 @@  static int con_write(struct tty_struct *tty, const unsigned char *buf, int count
 
 static int con_put_char(struct tty_struct *tty, unsigned char ch)
 {
-	if (in_interrupt())
-		return 0;	/* n_r3964 calls put_char() from interrupt context */
 	return do_con_write(tty, &ch, 1);
 }
 
diff --git a/include/linux/n_r3964.h b/include/linux/n_r3964.h
deleted file mode 100644
index 90a803aa42e8..000000000000
--- a/include/linux/n_r3964.h
+++ /dev/null
@@ -1,175 +0,0 @@ 
-/* r3964 linediscipline for linux
- *
- * -----------------------------------------------------------
- * Copyright by
- * Philips Automation Projects
- * Kassel (Germany)
- * -----------------------------------------------------------
- * This software may be used and distributed according to the terms of
- * the GNU General Public License, incorporated herein by reference.
- *
- * Author:
- * L. Haag
- *
- * $Log: r3964.h,v $
- * Revision 1.4  2005/12/21 19:54:24  Kurt Huwig <kurt huwig de>
- * Fixed HZ usage on 2.6 kernels
- * Removed unnecessary include
- *
- * Revision 1.3  2001/03/18 13:02:24  dwmw2
- * Fix timer usage, use spinlocks properly.
- *
- * Revision 1.2  2001/03/18 12:53:15  dwmw2
- * Merge changes in 2.4.2
- *
- * Revision 1.1.1.1  1998/10/13 16:43:14  dwmw2
- * This'll screw the version control
- *
- * Revision 1.6  1998/09/30 00:40:38  dwmw2
- * Updated to use kernel's N_R3964 if available
- *
- * Revision 1.4  1998/04/02 20:29:44  lhaag
- * select, blocking, ...
- *
- * Revision 1.3  1998/02/12 18:58:43  root
- * fixed some memory leaks
- * calculation of checksum characters
- *
- * Revision 1.2  1998/02/07 13:03:17  root
- * ioctl read_telegram
- *
- * Revision 1.1  1998/02/06 19:19:43  root
- * Initial revision
- *
- *
- */
-#ifndef __LINUX_N_R3964_H__
-#define __LINUX_N_R3964_H__
-
-
-#include <linux/param.h>
-#include <uapi/linux/n_r3964.h>
-
-/*
- * Common ascii handshake characters:
- */
-
-#define STX 0x02
-#define ETX 0x03
-#define DLE 0x10
-#define NAK 0x15
-
-/*
- * Timeouts (from milliseconds to jiffies)
- */
-
-#define R3964_TO_QVZ ((550)*HZ/1000)
-#define R3964_TO_ZVZ ((220)*HZ/1000)
-#define R3964_TO_NO_BUF ((400)*HZ/1000)
-#define R3964_NO_TX_ROOM ((100)*HZ/1000)
-#define R3964_TO_RX_PANIC ((4000)*HZ/1000)
-#define R3964_MAX_RETRIES 5
-
-
-enum { R3964_IDLE, 
-	   R3964_TX_REQUEST, R3964_TRANSMITTING, 
-	   R3964_WAIT_ZVZ_BEFORE_TX_RETRY, R3964_WAIT_FOR_TX_ACK,
-	   R3964_WAIT_FOR_RX_BUF,
-	   R3964_RECEIVING, R3964_WAIT_FOR_BCC, R3964_WAIT_FOR_RX_REPEAT
-	   };
-
-/*
- * All open file-handles are 'clients' and are stored in a linked list:
- */
-
-struct r3964_message;
-
-struct r3964_client_info {
-	spinlock_t     lock;
-	struct pid    *pid;
-	unsigned int   sig_flags;
-
-	struct r3964_client_info *next;
-
-	struct r3964_message *first_msg;
-	struct r3964_message *last_msg;
-	struct r3964_block_header *next_block_to_read;
-	int            msg_count;
-};
-
-
-
-struct r3964_block_header;
-
-/* internal version of client_message: */
-struct r3964_message {
-	  int     msg_id;
-	  int     arg;
-	  int     error_code;
-	  struct r3964_block_header *block;
-	  struct r3964_message *next;
-};
-
-/*
- * Header of received block in rx_buf/tx_buf:
- */
-
-struct r3964_block_header 
-{
-	unsigned int length;             /* length in chars without header */
-	unsigned char *data;             /* usually data is located 
-                                        immediately behind this struct */
-	unsigned int locks;              /* only used in rx_buffer */
-	  
-    struct r3964_block_header *next;
-	struct r3964_client_info *owner;  /* =NULL in rx_buffer */
-};
-
-/*
- * If rx_buf hasn't enough space to store R3964_MTU chars,
- * we will reject all incoming STX-requests by sending NAK.
- */
-
-#define RX_BUF_SIZE    4000
-#define TX_BUF_SIZE    4000
-#define R3964_MAX_BLOCKS_IN_RX_QUEUE 100
-
-#define R3964_PARITY 0x0001
-#define R3964_FRAME  0x0002
-#define R3964_OVERRUN 0x0004
-#define R3964_UNKNOWN 0x0008
-#define R3964_BREAK   0x0010
-#define R3964_CHECKSUM 0x0020
-#define R3964_ERROR  0x003f
-#define R3964_BCC   0x4000
-#define R3964_DEBUG 0x8000
-
-
-struct r3964_info {
-	spinlock_t     lock;
-	struct tty_struct *tty;
-	unsigned char priority;
-	unsigned char *rx_buf;            /* ring buffer */
-	unsigned char *tx_buf;
-
-	struct r3964_block_header *rx_first;
-	struct r3964_block_header *rx_last;
-	struct r3964_block_header *tx_first;
-	struct r3964_block_header *tx_last;
-	unsigned int tx_position;
-        unsigned int rx_position;
-	unsigned char last_rx;
-	unsigned char bcc;
-        unsigned int  blocks_in_rx_queue;
-
-	struct mutex read_lock;		/* serialize r3964_read */
-
-	struct r3964_client_info *firstClient;
-	unsigned int state;
-	unsigned int flags;
-
-	struct timer_list tmr;
-	int nRetry;
-};
-
-#endif
diff --git a/include/uapi/linux/n_r3964.h b/include/uapi/linux/n_r3964.h
deleted file mode 100644
index 6bbd18520f30..000000000000
--- a/include/uapi/linux/n_r3964.h
+++ /dev/null
@@ -1,99 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
-/* r3964 linediscipline for linux
- *
- * -----------------------------------------------------------
- * Copyright by
- * Philips Automation Projects
- * Kassel (Germany)
- * -----------------------------------------------------------
- * This software may be used and distributed according to the terms of
- * the GNU General Public License, incorporated herein by reference.
- *
- * Author:
- * L. Haag
- *
- * $Log: r3964.h,v $
- * Revision 1.4  2005/12/21 19:54:24  Kurt Huwig <kurt huwig de>
- * Fixed HZ usage on 2.6 kernels
- * Removed unnecessary include
- *
- * Revision 1.3  2001/03/18 13:02:24  dwmw2
- * Fix timer usage, use spinlocks properly.
- *
- * Revision 1.2  2001/03/18 12:53:15  dwmw2
- * Merge changes in 2.4.2
- *
- * Revision 1.1.1.1  1998/10/13 16:43:14  dwmw2
- * This'll screw the version control
- *
- * Revision 1.6  1998/09/30 00:40:38  dwmw2
- * Updated to use kernel's N_R3964 if available
- *
- * Revision 1.4  1998/04/02 20:29:44  lhaag
- * select, blocking, ...
- *
- * Revision 1.3  1998/02/12 18:58:43  root
- * fixed some memory leaks
- * calculation of checksum characters
- *
- * Revision 1.2  1998/02/07 13:03:17  root
- * ioctl read_telegram
- *
- * Revision 1.1  1998/02/06 19:19:43  root
- * Initial revision
- *
- *
- */
-
-#ifndef _UAPI__LINUX_N_R3964_H__
-#define _UAPI__LINUX_N_R3964_H__
-
-/* line disciplines for r3964 protocol */
-
-
-/*
- * Ioctl-commands
- */
-
-#define R3964_ENABLE_SIGNALS      0x5301
-#define R3964_SETPRIORITY         0x5302
-#define R3964_USE_BCC             0x5303
-#define R3964_READ_TELEGRAM       0x5304
-
-/* Options for R3964_SETPRIORITY */
-#define R3964_MASTER   0
-#define R3964_SLAVE    1
-
-/* Options for R3964_ENABLE_SIGNALS */
-#define R3964_SIG_ACK   0x0001
-#define R3964_SIG_DATA  0x0002
-#define R3964_SIG_ALL   0x000f
-#define R3964_SIG_NONE  0x0000
-#define R3964_USE_SIGIO 0x1000
-
-/*
- * r3964 operation states:
- */
-
-/* types for msg_id: */
-enum {R3964_MSG_ACK=1, R3964_MSG_DATA };
-
-#define R3964_MAX_MSG_COUNT 32
-
-/* error codes for client messages */
-#define R3964_OK 0        /* no error. */
-#define R3964_TX_FAIL -1  /* transmission error, block NOT sent */
-#define R3964_OVERFLOW -2 /* msg queue overflow */
-
-/* the client gets this struct when calling read(fd,...): */
-struct r3964_client_message {
-	  int     msg_id;
-	  int     arg;
-	  int     error_code;
-};
-
-#define R3964_MTU      256
-
-
-
-#endif /* _UAPI__LINUX_N_R3964_H__ */