[PATCH v2 00/11] tty: random fixes and cleanups

[PATCH v2 00/11] tty: random fixes and cleanups

[Jiri Slaby (SUSE)]

Hi,

this is a series of locally accumulated patches over past months.

The series:
* makes mctp and 6pack use u8s,
* cleans up 6pack a bit,
* fixes two coverity reports,
* uses guard() to make some of the tty function easier to follow.

Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: linux-hams@vger.kernel.org
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: netdev@vger.kernel.org
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-usb@vger.kernel.org
Cc: Mathias Nyman <mathias.nyman@intel.com>

[v2]
 * fixed "serial: use guards for simple mutex locks"
 * added also previously missed xhci dbgtty patches

Jiri Slaby (SUSE) (11):
  serial: use guards for simple mutex locks
  mxser: remove stale comment
  mxser: remove doubled sets of close times
  xhci: dbgtty: remove kfifo_out() wrapper
  xhci: dbgtty: use kfifo from tty_port struct
  mctp: serial: propagage new tty types
  6pack: remove sixpack::rbuff
  6pack: drop sixpack::mtu
  6pack: drop sixpack::buffsize
  6pack: remove global strings
  6pack: propagage new tty types

 drivers/net/hamradio/6pack.c     |  60 ++++++----------
 drivers/net/mctp/mctp-serial.c   |  23 ++++---
 drivers/tty/mxser.c              |   5 --
 drivers/tty/serial/serial_core.c | 113 +++++++++++++------------------
 drivers/usb/host/xhci-dbgcap.h   |   1 -
 drivers/usb/host/xhci-dbgtty.c   |  30 +++-----
 6 files changed, 88 insertions(+), 144 deletions(-)

-- 
2.46.0

[PATCH v2 01/11] serial: use guards for simple mutex locks

[Jiri Slaby (SUSE)]

Guards can help to make the code more readable. So use it wherever they
do so.

On many places labels and 'ret' locals are eliminated completely.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>

---
[v2] change also the third goto in uart_suspend_port().
     How could this only slip through?
---
 drivers/tty/serial/serial_core.c | 113 +++++++++++++------------------
 1 file changed, 47 insertions(+), 66 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 61fbc730c01b..d94d73e45fb6 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1104,21 +1104,19 @@ static int uart_tiocmget(struct tty_struct *tty)
 	struct uart_state *state = tty->driver_data;
 	struct tty_port *port = &state->port;
 	struct uart_port *uport;
-	int result = -EIO;
+	int result;
+
+	guard(mutex)(&port->mutex);
 
-	mutex_lock(&port->mutex);
 	uport = uart_port_check(state);
-	if (!uport)
-		goto out;
+	if (!uport || tty_io_error(tty))
+		return -EIO;
+
+	uart_port_lock_irq(uport);
+	result = uport->mctrl;
+	result |= uport->ops->get_mctrl(uport);
+	uart_port_unlock_irq(uport);
 
-	if (!tty_io_error(tty)) {
-		uart_port_lock_irq(uport);
-		result = uport->mctrl;
-		result |= uport->ops->get_mctrl(uport);
-		uart_port_unlock_irq(uport);
-	}
-out:
-	mutex_unlock(&port->mutex);
 	return result;
 }
 
@@ -1128,20 +1126,16 @@ uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
 	struct uart_state *state = tty->driver_data;
 	struct tty_port *port = &state->port;
 	struct uart_port *uport;
-	int ret = -EIO;
 
-	mutex_lock(&port->mutex);
+	guard(mutex)(&port->mutex);
+
 	uport = uart_port_check(state);
-	if (!uport)
-		goto out;
+	if (!uport || tty_io_error(tty))
+		return -EIO;
 
-	if (!tty_io_error(tty)) {
-		uart_update_mctrl(uport, set, clear);
-		ret = 0;
-	}
-out:
-	mutex_unlock(&port->mutex);
-	return ret;
+	uart_update_mctrl(uport, set, clear);
+
+	return 0;
 }
 
 static int uart_break_ctl(struct tty_struct *tty, int break_state)
@@ -1149,19 +1143,17 @@ static int uart_break_ctl(struct tty_struct *tty, int break_state)
 	struct uart_state *state = tty->driver_data;
 	struct tty_port *port = &state->port;
 	struct uart_port *uport;
-	int ret = -EIO;
 
-	mutex_lock(&port->mutex);
+	guard(mutex)(&port->mutex);
+
 	uport = uart_port_check(state);
 	if (!uport)
-		goto out;
+		return -EIO;
 
 	if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
 		uport->ops->break_ctl(uport, break_state);
-	ret = 0;
-out:
-	mutex_unlock(&port->mutex);
-	return ret;
+
+	return 0;
 }
 
 static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
@@ -1178,17 +1170,14 @@ static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
 	 * changing, and hence any extra opens of the port while
 	 * we're auto-configuring.
 	 */
-	if (mutex_lock_interruptible(&port->mutex))
-		return -ERESTARTSYS;
+	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &port->mutex) {
+		uport = uart_port_check(state);
+		if (!uport)
+			return -EIO;
 
-	uport = uart_port_check(state);
-	if (!uport) {
-		ret = -EIO;
-		goto out;
-	}
+		if (tty_port_users(port) != 1)
+			return -EBUSY;
 
-	ret = -EBUSY;
-	if (tty_port_users(port) == 1) {
 		uart_shutdown(tty, state);
 
 		/*
@@ -1209,14 +1198,15 @@ static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
 		uport->ops->config_port(uport, flags);
 
 		ret = uart_startup(tty, state, true);
-		if (ret == 0)
-			tty_port_set_initialized(port, true);
+		if (ret < 0)
+			return ret;
 		if (ret > 0)
-			ret = 0;
+			return 0;
+
+		tty_port_set_initialized(port, true);
 	}
-out:
-	mutex_unlock(&port->mutex);
-	return ret;
+
+	return 0;
 }
 
 static void uart_enable_ms(struct uart_port *uport)
@@ -1711,10 +1701,11 @@ static void uart_set_termios(struct tty_struct *tty,
 	unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
 	bool sw_changed = false;
 
-	mutex_lock(&state->port.mutex);
+	guard(mutex)(&state->port.mutex);
+
 	uport = uart_port_check(state);
 	if (!uport)
-		goto out;
+		return;
 
 	/*
 	 * Drivers doing software flow control also need to know
@@ -1737,9 +1728,8 @@ static void uart_set_termios(struct tty_struct *tty,
 	    tty->termios.c_ospeed == old_termios->c_ospeed &&
 	    tty->termios.c_ispeed == old_termios->c_ispeed &&
 	    ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
-	    !sw_changed) {
-		goto out;
-	}
+	    !sw_changed)
+		return;
 
 	uart_change_line_settings(tty, state, old_termios);
 	/* reload cflag from termios; port driver may have overridden flags */
@@ -1756,8 +1746,6 @@ static void uart_set_termios(struct tty_struct *tty,
 			mask |= TIOCM_RTS;
 		uart_set_mctrl(uport, mask);
 	}
-out:
-	mutex_unlock(&state->port.mutex);
 }
 
 /*
@@ -2051,10 +2039,11 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 	unsigned int status;
 	int mmio;
 
-	mutex_lock(&port->mutex);
+	guard(mutex)(&port->mutex);
+
 	uport = uart_port_check(state);
 	if (!uport)
-		goto out;
+		return;
 
 	mmio = uport->iotype >= UPIO_MEM;
 	seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
@@ -2066,7 +2055,7 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 
 	if (uport->type == PORT_UNKNOWN) {
 		seq_putc(m, '\n');
-		goto out;
+		return;
 	}
 
 	if (capable(CAP_SYS_ADMIN)) {
@@ -2117,8 +2106,6 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 	seq_putc(m, '\n');
 #undef STATBIT
 #undef INFOBIT
-out:
-	mutex_unlock(&port->mutex);
 }
 
 static int uart_proc_show(struct seq_file *m, void *v)
@@ -2395,13 +2382,12 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 	struct device *tty_dev;
 	struct uart_match match = {uport, drv};
 
-	mutex_lock(&port->mutex);
+	guard(mutex)(&port->mutex);
 
 	tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
 	if (tty_dev && device_may_wakeup(tty_dev)) {
 		enable_irq_wake(uport->irq);
 		put_device(tty_dev);
-		mutex_unlock(&port->mutex);
 		return 0;
 	}
 	put_device(tty_dev);
@@ -2419,7 +2405,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 			uart_port_unlock_irq(uport);
 		}
 		device_set_awake_path(uport->dev);
-		goto unlock;
+		return 0;
 	}
 
 	uport->suspended = 1;
@@ -2462,8 +2448,6 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		console_stop(uport->cons);
 
 	uart_change_pm(state, UART_PM_STATE_OFF);
-unlock:
-	mutex_unlock(&port->mutex);
 
 	return 0;
 }
@@ -2477,14 +2461,13 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 	struct uart_match match = {uport, drv};
 	struct ktermios termios;
 
-	mutex_lock(&port->mutex);
+	guard(mutex)(&port->mutex);
 
 	tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
 	if (!uport->suspended && device_may_wakeup(tty_dev)) {
 		if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
 			disable_irq_wake(uport->irq);
 		put_device(tty_dev);
-		mutex_unlock(&port->mutex);
 		return 0;
 	}
 	put_device(tty_dev);
@@ -2557,8 +2540,6 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		tty_port_set_suspended(port, false);
 	}
 
-	mutex_unlock(&port->mutex);
-
 	return 0;
 }
 EXPORT_SYMBOL(uart_resume_port);
-- 
2.46.0

[PATCH v2 02/11] mxser: remove stale comment

[Jiri Slaby (SUSE)]

The comment mentions ISA removed long time ago. It also comments on
.driver_data pointing to above structures. That is not true either.
Remove that.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/mxser.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 5b97e420a95f..9a9a67b5afa0 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -208,9 +208,6 @@ static const struct {
 };
 #define UART_INFO_NUM	ARRAY_SIZE(Gpci_uart_info)
 
-
-/* driver_data correspond to the lines in the structure above
-   see also ISA probe function before you change something */
 static const struct pci_device_id mxser_pcibrds[] = {
 	{ PCI_DEVICE_DATA(MOXA, C168,		8) },
 	{ PCI_DEVICE_DATA(MOXA, C104,		4) },
-- 
2.46.0

[PATCH v2 03/11] mxser: remove doubled sets of close times

[Jiri Slaby (SUSE)]

tty_port::close_delay and ::closing_wait are set in tty_port_init() few
lines above already, no need to reset them (to the same values).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/mxser.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 9a9a67b5afa0..6cfef88a18e3 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1770,8 +1770,6 @@ static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
 
 		mxser_process_txrx_fifo(info);
 
-		info->port.close_delay = 5 * HZ / 10;
-		info->port.closing_wait = 30 * HZ;
 		spin_lock_init(&info->slock);
 
 		/* before set INT ISR, disable all int */
-- 
2.46.0

[PATCH v2 04/11] xhci: dbgtty: remove kfifo_out() wrapper

[Jiri Slaby (SUSE)]

There is no need to check against kfifo_len() before kfifo_out(). Just
ask the latter for data and it tells how much it retrieved. Or returns 0
in case there are no more.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
---
 drivers/usb/host/xhci-dbgtty.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index b74e98e94393..64ea96494997 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -24,19 +24,6 @@ static inline struct dbc_port *dbc_to_port(struct xhci_dbc *dbc)
 	return dbc->priv;
 }
 
-static unsigned int
-dbc_send_packet(struct dbc_port *port, char *packet, unsigned int size)
-{
-	unsigned int		len;
-
-	len = kfifo_len(&port->write_fifo);
-	if (len < size)
-		size = len;
-	if (size != 0)
-		size = kfifo_out(&port->write_fifo, packet, size);
-	return size;
-}
-
 static int dbc_start_tx(struct dbc_port *port)
 	__releases(&port->port_lock)
 	__acquires(&port->port_lock)
@@ -49,7 +36,7 @@ static int dbc_start_tx(struct dbc_port *port)
 
 	while (!list_empty(pool)) {
 		req = list_entry(pool->next, struct dbc_request, list_pool);
-		len = dbc_send_packet(port, req->buf, DBC_MAX_PACKET);
+		len = kfifo_out(&port->write_fifo, req->buf, DBC_MAX_PACKET);
 		if (len == 0)
 			break;
 		do_tty_wake = true;
-- 
2.46.0

[PATCH v2 05/11] xhci: dbgtty: use kfifo from tty_port struct

[Jiri Slaby (SUSE)]

There is no need to define one in a custom structure. The tty_port one
is free to use.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
---
 drivers/usb/host/xhci-dbgcap.h |  1 -
 drivers/usb/host/xhci-dbgtty.c | 17 +++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h
index 0118c6288a3c..eab59d921e22 100644
--- a/drivers/usb/host/xhci-dbgcap.h
+++ b/drivers/usb/host/xhci-dbgcap.h
@@ -110,7 +110,6 @@ struct dbc_port {
 	struct tasklet_struct		push;
 
 	struct list_head		write_pool;
-	struct kfifo			write_fifo;
 
 	bool				registered;
 };
diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index 64ea96494997..881f5a7e6e0e 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -36,7 +36,7 @@ static int dbc_start_tx(struct dbc_port *port)
 
 	while (!list_empty(pool)) {
 		req = list_entry(pool->next, struct dbc_request, list_pool);
-		len = kfifo_out(&port->write_fifo, req->buf, DBC_MAX_PACKET);
+		len = kfifo_out(&port->port.xmit_fifo, req->buf, DBC_MAX_PACKET);
 		if (len == 0)
 			break;
 		do_tty_wake = true;
@@ -203,7 +203,7 @@ static ssize_t dbc_tty_write(struct tty_struct *tty, const u8 *buf,
 
 	spin_lock_irqsave(&port->port_lock, flags);
 	if (count)
-		count = kfifo_in(&port->write_fifo, buf, count);
+		count = kfifo_in(&port->port.xmit_fifo, buf, count);
 	dbc_start_tx(port);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
@@ -217,7 +217,7 @@ static int dbc_tty_put_char(struct tty_struct *tty, u8 ch)
 	int			status;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	status = kfifo_put(&port->write_fifo, ch);
+	status = kfifo_put(&port->port.xmit_fifo, ch);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return status;
@@ -240,7 +240,7 @@ static unsigned int dbc_tty_write_room(struct tty_struct *tty)
 	unsigned int		room;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	room = kfifo_avail(&port->write_fifo);
+	room = kfifo_avail(&port->port.xmit_fifo);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return room;
@@ -253,7 +253,7 @@ static unsigned int dbc_tty_chars_in_buffer(struct tty_struct *tty)
 	unsigned int		chars;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	chars = kfifo_len(&port->write_fifo);
+	chars = kfifo_len(&port->port.xmit_fifo);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return chars;
@@ -411,7 +411,8 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc)
 		goto err_idr;
 	}
 
-	ret = kfifo_alloc(&port->write_fifo, DBC_WRITE_BUF_SIZE, GFP_KERNEL);
+	ret = kfifo_alloc(&port->port.xmit_fifo, DBC_WRITE_BUF_SIZE,
+			  GFP_KERNEL);
 	if (ret)
 		goto err_exit_port;
 
@@ -440,7 +441,7 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc)
 	xhci_dbc_free_requests(&port->read_pool);
 	xhci_dbc_free_requests(&port->write_pool);
 err_free_fifo:
-	kfifo_free(&port->write_fifo);
+	kfifo_free(&port->port.xmit_fifo);
 err_exit_port:
 	idr_remove(&dbc_tty_minors, port->minor);
 err_idr:
@@ -465,7 +466,7 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc)
 	idr_remove(&dbc_tty_minors, port->minor);
 	mutex_unlock(&dbc_tty_minors_lock);
 
-	kfifo_free(&port->write_fifo);
+	kfifo_free(&port->port.xmit_fifo);
 	xhci_dbc_free_requests(&port->read_pool);
 	xhci_dbc_free_requests(&port->read_queue);
 	xhci_dbc_free_requests(&port->write_pool);
-- 
2.46.0

[PATCH v2 06/11] mctp: serial: propagage new tty types

[Jiri Slaby (SUSE)]

In tty, u8 is now used for data, ssize_t for sizes (with possible
negative error codes). Propagate these types (and use unsigned in
next_chunk_len()) to mctp.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 drivers/net/mctp/mctp-serial.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c
index 5bf6fdff701c..78bd59b0930d 100644
--- a/drivers/net/mctp/mctp-serial.c
+++ b/drivers/net/mctp/mctp-serial.c
@@ -64,18 +64,18 @@ struct mctp_serial {
 	u16			txfcs, rxfcs, rxfcs_rcvd;
 	unsigned int		txlen, rxlen;
 	unsigned int		txpos, rxpos;
-	unsigned char		txbuf[BUFSIZE],
+	u8			txbuf[BUFSIZE],
 				rxbuf[BUFSIZE];
 };
 
-static bool needs_escape(unsigned char c)
+static bool needs_escape(u8 c)
 {
 	return c == BYTE_ESC || c == BYTE_FRAME;
 }
 
-static int next_chunk_len(struct mctp_serial *dev)
+static unsigned int next_chunk_len(struct mctp_serial *dev)
 {
-	int i;
+	unsigned int i;
 
 	/* either we have no bytes to send ... */
 	if (dev->txpos == dev->txlen)
@@ -99,7 +99,7 @@ static int next_chunk_len(struct mctp_serial *dev)
 	return i;
 }
 
-static int write_chunk(struct mctp_serial *dev, unsigned char *buf, int len)
+static ssize_t write_chunk(struct mctp_serial *dev, u8 *buf, size_t len)
 {
 	return dev->tty->ops->write(dev->tty, buf, len);
 }
@@ -108,9 +108,10 @@ static void mctp_serial_tx_work(struct work_struct *work)
 {
 	struct mctp_serial *dev = container_of(work, struct mctp_serial,
 					       tx_work);
-	unsigned char c, buf[3];
 	unsigned long flags;
-	int len, txlen;
+	ssize_t txlen;
+	unsigned int len;
+	u8 c, buf[3];
 
 	spin_lock_irqsave(&dev->lock, flags);
 
@@ -293,7 +294,7 @@ static void mctp_serial_rx(struct mctp_serial *dev)
 	dev->netdev->stats.rx_bytes += dev->rxlen;
 }
 
-static void mctp_serial_push_header(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push_header(struct mctp_serial *dev, u8 c)
 {
 	switch (dev->rxpos) {
 	case 0:
@@ -323,7 +324,7 @@ static void mctp_serial_push_header(struct mctp_serial *dev, unsigned char c)
 	}
 }
 
-static void mctp_serial_push_trailer(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push_trailer(struct mctp_serial *dev, u8 c)
 {
 	switch (dev->rxpos) {
 	case 0:
@@ -347,7 +348,7 @@ static void mctp_serial_push_trailer(struct mctp_serial *dev, unsigned char c)
 	}
 }
 
-static void mctp_serial_push(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push(struct mctp_serial *dev, u8 c)
 {
 	switch (dev->rxstate) {
 	case STATE_IDLE:
@@ -394,7 +395,7 @@ static void mctp_serial_tty_receive_buf(struct tty_struct *tty, const u8 *c,
 					const u8 *f, size_t len)
 {
 	struct mctp_serial *dev = tty->disc_data;
-	int i;
+	size_t i;
 
 	if (!netif_running(dev->netdev))
 		return;
-- 
2.46.0

[PATCH v2 07/11] 6pack: remove sixpack::rbuff

[Jiri Slaby (SUSE)]

It's unused (except allocation and free).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 6ed38a3cdd73..29906901a734 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -88,7 +88,6 @@ struct sixpack {
 	struct net_device	*dev;		/* easy for intr handling  */
 
 	/* These are pointers to the malloc()ed frame buffers. */
-	unsigned char		*rbuff;		/* receiver buffer	*/
 	int			rcount;         /* received chars counter  */
 	unsigned char		*xbuff;		/* transmitter buffer	*/
 	unsigned char		*xhead;         /* next byte to XMIT */
@@ -544,7 +543,7 @@ static inline int tnc_init(struct sixpack *sp)
  */
 static int sixpack_open(struct tty_struct *tty)
 {
-	char *rbuff = NULL, *xbuff = NULL;
+	char *xbuff = NULL;
 	struct net_device *dev;
 	struct sixpack *sp;
 	unsigned long len;
@@ -574,10 +573,8 @@ static int sixpack_open(struct tty_struct *tty)
 
 	len = dev->mtu * 2;
 
-	rbuff = kmalloc(len + 4, GFP_KERNEL);
 	xbuff = kmalloc(len + 4, GFP_KERNEL);
-
-	if (rbuff == NULL || xbuff == NULL) {
+	if (xbuff == NULL) {
 		err = -ENOBUFS;
 		goto out_free;
 	}
@@ -586,7 +583,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->tty = tty;
 
-	sp->rbuff	= rbuff;
 	sp->xbuff	= xbuff;
 
 	sp->mtu		= AX25_MTU + 73;
@@ -631,7 +627,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 out_free:
 	kfree(xbuff);
-	kfree(rbuff);
 
 	free_netdev(dev);
 
@@ -676,7 +671,6 @@ static void sixpack_close(struct tty_struct *tty)
 	del_timer_sync(&sp->resync_t);
 
 	/* Free all 6pack frame buffers after unreg. */
-	kfree(sp->rbuff);
 	kfree(sp->xbuff);
 
 	free_netdev(sp->dev);
-- 
2.46.0

[PATCH v2 08/11] 6pack: drop sixpack::mtu

[Jiri Slaby (SUSE)]

It holds a constant (AX25_MTU + 73), so use that constant in place of
the single use directly.

And remove the stale comment.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 29906901a734..f8235b1b60e9 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -100,7 +100,6 @@ struct sixpack {
 	unsigned int		rx_count_cooked;
 	spinlock_t		rxlock;
 
-	int			mtu;		/* Our mtu (to spot changes!) */
 	int			buffsize;       /* Max buffers sizes */
 
 	unsigned long		flags;		/* Flag values/ mode etc */
@@ -166,7 +165,7 @@ static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
 	unsigned char *msg, *p = icp;
 	int actual, count;
 
-	if (len > sp->mtu) {	/* sp->mtu = AX25_MTU = max. PACLEN = 256 */
+	if (len > AX25_MTU + 73) {
 		msg = "oversized transmit packet!";
 		goto out_drop;
 	}
@@ -585,7 +584,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->xbuff	= xbuff;
 
-	sp->mtu		= AX25_MTU + 73;
 	sp->buffsize	= len;
 	sp->rcount	= 0;
 	sp->rx_count	= 0;
-- 
2.46.0

[PATCH v2 09/11] 6pack: drop sixpack::buffsize

[Jiri Slaby (SUSE)]

It's never read.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index f8235b1b60e9..25d6d2308130 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -100,8 +100,6 @@ struct sixpack {
 	unsigned int		rx_count_cooked;
 	spinlock_t		rxlock;
 
-	int			buffsize;       /* Max buffers sizes */
-
 	unsigned long		flags;		/* Flag values/ mode etc */
 	unsigned char		mode;		/* 6pack mode */
 
@@ -584,7 +582,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->xbuff	= xbuff;
 
-	sp->buffsize	= len;
 	sp->rcount	= 0;
 	sp->rx_count	= 0;
 	sp->rx_count_cooked = 0;
-- 
2.46.0

[PATCH v2 10/11] 6pack: remove global strings

[Jiri Slaby (SUSE)]

They are __init, so they are freed after init is done. But this
obfuscates the code.

Provided these days, we usually don't print anything if everything has
gone fine, drop the info print completely (along with now unused and
always artificial SIXPACK_VERSION).

And move the other string into the printk proper (while converting from
KERN_ERR to pr_err()).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 25d6d2308130..5c47730f5d58 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -37,8 +37,6 @@
 #include <linux/semaphore.h>
 #include <linux/refcount.h>
 
-#define SIXPACK_VERSION    "Revision: 0.3.0"
-
 /* sixpack priority commands */
 #define SIXP_SEOF		0x40	/* start and end of a 6pack frame */
 #define SIXP_TX_URUN		0x48	/* transmit overrun */
@@ -745,21 +743,14 @@ static struct tty_ldisc_ops sp_ldisc = {
 
 /* Initialize 6pack control device -- register 6pack line discipline */
 
-static const char msg_banner[]  __initconst = KERN_INFO \
-	"AX.25: 6pack driver, " SIXPACK_VERSION "\n";
-static const char msg_regfail[] __initconst = KERN_ERR  \
-	"6pack: can't register line discipline (err = %d)\n";
-
 static int __init sixpack_init_driver(void)
 {
 	int status;
 
-	printk(msg_banner);
-
 	/* Register the provided line protocol discipline */
 	status = tty_register_ldisc(&sp_ldisc);
 	if (status)
-		printk(msg_regfail, status);
+		pr_err("6pack: can't register line discipline (err = %d)\n", status);
 
 	return status;
 }
-- 
2.46.0

[PATCH v2 11/11] 6pack: propagage new tty types

[Jiri Slaby (SUSE)]

In tty, u8 is now used for data, ssize_t for sizes (with possible
negative error codes). Propagate these types to 6pack.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 5c47730f5d58..3bf6785f9057 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -91,8 +91,8 @@ struct sixpack {
 	unsigned char		*xhead;         /* next byte to XMIT */
 	int			xleft;          /* bytes left in XMIT queue  */
 
-	unsigned char		raw_buf[4];
-	unsigned char		cooked_buf[400];
+	u8			raw_buf[4];
+	u8			cooked_buf[400];
 
 	unsigned int		rx_count;
 	unsigned int		rx_count_cooked;
@@ -107,8 +107,8 @@ struct sixpack {
 	unsigned char		slottime;
 	unsigned char		duplex;
 	unsigned char		led_state;
-	unsigned char		status;
-	unsigned char		status1;
+	u8			status;
+	u8			status1;
 	unsigned char		status2;
 	unsigned char		tx_enable;
 	unsigned char		tnc_state;
@@ -122,7 +122,7 @@ struct sixpack {
 
 #define AX25_6PACK_HEADER_LEN 0
 
-static void sixpack_decode(struct sixpack *, const unsigned char[], int);
+static void sixpack_decode(struct sixpack *, const u8 *, size_t);
 static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char);
 
 /*
@@ -327,7 +327,7 @@ static void sp_bump(struct sixpack *sp, char cmd)
 {
 	struct sk_buff *skb;
 	int count;
-	unsigned char *ptr;
+	u8 *ptr;
 
 	count = sp->rcount + 1;
 
@@ -425,7 +425,7 @@ static void sixpack_receive_buf(struct tty_struct *tty, const u8 *cp,
 				const u8 *fp, size_t count)
 {
 	struct sixpack *sp;
-	int count1;
+	size_t count1;
 
 	if (!count)
 		return;
@@ -800,9 +800,9 @@ static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw,
 
 /* decode 4 sixpack-encoded bytes into 3 data bytes */
 
-static void decode_data(struct sixpack *sp, unsigned char inbyte)
+static void decode_data(struct sixpack *sp, u8 inbyte)
 {
-	unsigned char *buf;
+	u8 *buf;
 
 	if (sp->rx_count != 3) {
 		sp->raw_buf[sp->rx_count++] = inbyte;
@@ -828,9 +828,9 @@ static void decode_data(struct sixpack *sp, unsigned char inbyte)
 
 /* identify and execute a 6pack priority command byte */
 
-static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
+static void decode_prio_command(struct sixpack *sp, u8 cmd)
 {
-	int actual;
+	ssize_t actual;
 
 	if ((cmd & SIXP_PRIO_DATA_MASK) != 0) {     /* idle ? */
 
@@ -878,9 +878,9 @@ static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
 
 /* identify and execute a standard 6pack command byte */
 
-static void decode_std_command(struct sixpack *sp, unsigned char cmd)
+static void decode_std_command(struct sixpack *sp, u8 cmd)
 {
-	unsigned char checksum = 0, rest = 0;
+	u8 checksum = 0, rest = 0;
 	short i;
 
 	switch (cmd & SIXP_CMD_MASK) {     /* normal command */
@@ -928,10 +928,10 @@ static void decode_std_command(struct sixpack *sp, unsigned char cmd)
 /* decode a 6pack packet */
 
 static void
-sixpack_decode(struct sixpack *sp, const unsigned char *pre_rbuff, int count)
+sixpack_decode(struct sixpack *sp, const u8 *pre_rbuff, size_t count)
 {
-	unsigned char inbyte;
-	int count1;
+	size_t count1;
+	u8 inbyte;
 
 	for (count1 = 0; count1 < count; count1++) {
 		inbyte = pre_rbuff[count1];
-- 
2.46.0