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

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox 2007-10-16 01:26:38 -07:00 committed by Linus Torvalds
parent e5f7178129
commit 2090ab05fe
1 changed files with 12 additions and 55 deletions
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67
drivers/serial/crisv10.c
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@ -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 */
}