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Commit 54c0f37e authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Linus Torvalds
Browse files

dz: handle special conditions on reception correctly 



Handle the read and ignore status masks correctly.  Handle the BREAK condition
as expected: a framing error with a null character is a BREAK, any other
framing error is a framing error indeed.

Signed-off-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 43d46ab1

drivers/serial/dz.c

+44 −38
Original line number Original line Diff line number Diff line
@@ -166,6 +166,7 @@ static void dz_enable_ms(struct uart_port *port) 
 */

 */

static inline void dz_receive_chars(struct dz_port *dport_in)

static inline void dz_receive_chars(struct dz_port *dport_in)

{

{

	struct uart_port *uport;

	struct dz_port *dport;

	struct dz_port *dport;

	struct tty_struct *tty = NULL;

	struct tty_struct *tty = NULL;

	struct uart_icount *icount;

	struct uart_icount *icount;
@@ -176,58 +177,57 @@ static inline void dz_receive_chars(struct dz_port *dport_in) 




	while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {

	while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {

		dport = &dz_ports[LINE(status)];

		dport = &dz_ports[LINE(status)];

		tty = dport->port.info->tty;	/* point to the proper dev */

		uport = &dport->port;

		tty = uport->info->tty;		/* point to the proper dev */





		ch = UCHAR(status);		/* grab the char */

		ch = UCHAR(status);		/* grab the char */

		flag = TTY_NORMAL;





		icount = &dport->port.icount;

		icount = &uport->icount;

		icount->rx++;

		icount->rx++;





		flag = TTY_NORMAL;

		if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) {

		if (status & DZ_FERR) {		/* frame error */



			/*

			/*

			 * There is no separate BREAK status bit, so

			 * There is no separate BREAK status bit, so treat

			 * treat framing errors as BREAKs for Magic SysRq

			 * null characters with framing errors as BREAKs;

			 * and SAK; normally, otherwise.

			 * normally, otherwise.  For this move the Framing

			 * Error bit to a simulated BREAK bit.

			 */

			 */

			if (uart_handle_break(&dport->port))

			if (!ch) {

				status |= (status & DZ_FERR) >>

					  (ffs(DZ_FERR) - ffs(DZ_BREAK));

				status &= ~DZ_FERR;

			}



			/* Handle SysRq/SAK & keep track of the statistics. */

			if (status & DZ_BREAK) {

				icount->brk++;

				if (uart_handle_break(uport))

					continue;

					continue;

			if (dport->port.flags & UPF_SAK)

			} else if (status & DZ_FERR)

				icount->frame++;

			else if (status & DZ_PERR)

				icount->parity++;

			if (status & DZ_OERR)

				icount->overrun++;



			status &= uport->read_status_mask;

			if (status & DZ_BREAK)

				flag = TTY_BREAK;

				flag = TTY_BREAK;

			else

			else if (status & DZ_FERR)

				flag = TTY_FRAME;

				flag = TTY_FRAME;

		} else if (status & DZ_OERR)	/* overrun error */

			else if (status & DZ_PERR)

			flag = TTY_OVERRUN;

		else if (status & DZ_PERR)	/* parity error */

				flag = TTY_PARITY;

				flag = TTY_PARITY;





		/* keep track of the statistics */

		switch (flag) {

		case TTY_FRAME:

			icount->frame++;

			break;

		case TTY_PARITY:

			icount->parity++;

			break;

		case TTY_OVERRUN:

			icount->overrun++;

			break;

		case TTY_BREAK:

			icount->brk++;

			break;

		default:

			break;

		}

		}





		if (uart_handle_sysrq_char(&dport->port, ch))

		if (uart_handle_sysrq_char(uport, ch))

			continue;

			continue;





		if ((status & dport->port.ignore_status_mask) == 0) {

		uart_insert_char(uport, status, DZ_OERR, ch, flag);

			uart_insert_char(&dport->port,

					 status, DZ_OERR, ch, flag);

		lines_rx[LINE(status)] = 1;

		lines_rx[LINE(status)] = 1;

	}

	}

	}

	for (i = 0; i < DZ_NB_PORT; i++)

	for (i = 0; i < DZ_NB_PORT; i++)

		if (lines_rx[i])

		if (lines_rx[i])

			tty_flip_buffer_push(dz_ports[i].port.info->tty);

			tty_flip_buffer_push(dz_ports[i].port.info->tty);
@@ -556,11 +556,17 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios, 
	dport->port.read_status_mask = DZ_OERR;

	dport->port.read_status_mask = DZ_OERR;

	if (termios->c_iflag & INPCK)

	if (termios->c_iflag & INPCK)

		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;

		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;

	if (termios->c_iflag & (BRKINT | PARMRK))

		dport->port.read_status_mask |= DZ_BREAK;





	/* characters to ignore */

	/* characters to ignore */

	uport->ignore_status_mask = 0;

	uport->ignore_status_mask = 0;

	if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))

		dport->port.ignore_status_mask |= DZ_OERR;

	if (termios->c_iflag & IGNPAR)

	if (termios->c_iflag & IGNPAR)

		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;

		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;

	if (termios->c_iflag & IGNBRK)

		dport->port.ignore_status_mask |= DZ_BREAK;





	spin_unlock_irqrestore(&dport->port.lock, flags);

	spin_unlock_irqrestore(&dport->port.lock, flags);

}

}

drivers/serial/dz.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -33,6 +33,8 @@ 
#define DZ_FERR        0x2000                 /* Frame error indicator */

#define DZ_FERR        0x2000                 /* Frame error indicator */

#define DZ_PERR        0x1000                 /* Parity error indicator */

#define DZ_PERR        0x1000                 /* Parity error indicator */





#define DZ_BREAK       0x0800                 /* BREAK event software flag */



#define LINE(x) ((x & DZ_LINE_MASK) >> 8)     /* Get the line number

#define LINE(x) ((x & DZ_LINE_MASK) >> 8)     /* Get the line number

                                                 from the input buffer */

                                                 from the input buffer */

#define UCHAR(x) ((unsigned char)(x & DZ_RBUF_MASK))

#define UCHAR(x) ((unsigned char)(x & DZ_RBUF_MASK))