Commit 2090ab05 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

tty: bring the old cris driver back somewhere into the realm of new tty buffering 



Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e5f71781

drivers/serial/crisv10.c

+12 −55
Original line number Diff line number Diff line
@@ -514,6 +514,8 @@ struct tty_driver *serial_driver; 
 * TTY_THRESHOLD_THROTTLE/UNTHROTTLE=128

 * BUF_SIZE can't be > 128

 */

#define CRIS_BUF_SIZE	512



/* Currently 16 descriptors x 128 bytes = 2048 bytes */

#define SERIAL_DESCR_BUF_SIZE 256
@@ -2497,55 +2499,18 @@ static void flush_to_flip_buffer(struct e100_serial *info) 
		return;

	}



	length = tty->flip.count;

	/* Don't flip more than the ldisc has room for.

	 * The return value from ldisc.receive_room(tty) - might not be up to

	 * date, the previous flip of up to TTY_FLIPBUF_SIZE might be on the

	 * processed and not accounted for yet.

	 * Since we use DMA, 1 SERIAL_DESCR_BUF_SIZE could be on the way.

	 * Lets buffer data here and let flow control take care of it.

	 * Since we normally flip large chunks, the ldisc don't react

	 * with throttle until too late if we flip to much.

	 */

	max_flip_size = tty->ldisc.receive_room(tty);

	if (max_flip_size < 0)

		max_flip_size = 0;

	if (max_flip_size <= (TTY_FLIPBUF_SIZE +         /* Maybe not accounted for */

			      length + info->recv_cnt +  /* We have this queued */

			      2*SERIAL_DESCR_BUF_SIZE +    /* This could be on the way */

			      TTY_THRESHOLD_THROTTLE)) { /* Some slack */

		/* check TTY_THROTTLED first so it indicates our state */

		if (!test_and_set_bit(TTY_THROTTLED, &tty->flags)) {

			DFLOW(DEBUG_LOG(info->line,"flush_to_flip throttles room %lu\n", max_flip_size));

			rs_throttle(tty);

		}

#if 0

		else if (max_flip_size <= (TTY_FLIPBUF_SIZE +         /* Maybe not accounted for */

					   length + info->recv_cnt +  /* We have this queued */

					   SERIAL_DESCR_BUF_SIZE +    /* This could be on the way */

					   TTY_THRESHOLD_THROTTLE)) { /* Some slack */

			DFLOW(DEBUG_LOG(info->line,"flush_to_flip throttles again! %lu\n", max_flip_size));

			rs_throttle(tty);

		}

#endif

	}



	if (max_flip_size > TTY_FLIPBUF_SIZE)

		max_flip_size = TTY_FLIPBUF_SIZE;



	while ((buffer = info->first_recv_buffer) && length < max_flip_size) {

	while ((buffer = info->first_recv_buffer) != NULL) {

		unsigned int count = buffer->length;



		if (length + count > max_flip_size)

			count = max_flip_size - length;

		count = tty_buffer_request_room(tty, count);

		if (count == 0) /* Throttle ?? */

			break;



		memcpy(tty->flip.char_buf_ptr + length, buffer->buffer, count);

		memset(tty->flip.flag_buf_ptr + length, TTY_NORMAL, count);

		tty->flip.flag_buf_ptr[length] = buffer->error;

		if (count > 1)

			tty_insert_flip_strings(tty, buffer->buffer, count - 1);

		tty_insert_flip_char(tty, buffer->buffer[count-1], buffer->error);



		length += count;

		info->recv_cnt -= count;

		DFLIP(DEBUG_LOG(info->line,"flip: %i\n", length));



		if (count == buffer->length) {

			info->first_recv_buffer = buffer->next;
@@ -2560,14 +2525,6 @@ static void flush_to_flip_buffer(struct e100_serial *info) 
	if (!info->first_recv_buffer)

		info->last_recv_buffer = NULL;



	tty->flip.count = length;

	DFLIP(if (tty->ldisc.chars_in_buffer(tty) > 3500) {

		DEBUG_LOG(info->line, "ldisc %lu\n",

			  tty->ldisc.chars_in_buffer(tty));

		DEBUG_LOG(info->line, "flip.count %lu\n",

			  tty->flip.count);

	      }

	      );

	restore_flags(flags);



	DFLIP(
@@ -2722,17 +2679,17 @@ struct e100_serial * handle_ser_rx_interrupt_no_dma(struct e100_serial *info) 
		printk("!NO TTY!\n");

		return info;

	}

	if (tty->flip.count >= TTY_FLIPBUF_SIZE - TTY_THRESHOLD_THROTTLE) {

	if (tty->flip.count >= CRIS_BUF_SIZE - TTY_THRESHOLD_THROTTLE) {

		/* check TTY_THROTTLED first so it indicates our state */

		if (!test_and_set_bit(TTY_THROTTLED, &tty->flags)) {

			DFLOW(DEBUG_LOG(info->line, "rs_throttle flip.count: %i\n", tty->flip.count));

			rs_throttle(tty);

		}

	}

	if (tty->flip.count >= TTY_FLIPBUF_SIZE) {

	if (tty->flip.count >= CRIS_BUF_SIZE) {

		DEBUG_LOG(info->line, "force FLIP! %i\n", tty->flip.count);

		tty->flip.work.func((void *) tty);

		if (tty->flip.count >= TTY_FLIPBUF_SIZE) {

		if (tty->flip.count >= CRIS_BUF_SIZE) {

			DEBUG_LOG(info->line, "FLIP FULL! %i\n", tty->flip.count);

			return info;		/* if TTY_DONT_FLIP is set */

		}