The patch titled
add receive_room flow control to flush_to_ldisc
has been added to the -mm tree. Its filename is
add-receive_room-flow-control-to-flush_to_ldisc.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: add receive_room flow control to flush_to_ldisc
From: Paul Fulghum <paulkf@xxxxxxxxxxxxx>
Flush data serially to line discipline in blocks no larger than
tty->receive_room to avoid losing data if line discipline is busy (such as
N_TTY operating at high speed on heavily loaded system) or does not accept
data in large blocks (such as N_MOUSE).
Signed-off-by: Paul Fulghum <paulkf@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/char/tty_io.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff -puN drivers/char/tty_io.c~add-receive_room-flow-control-to-flush_to_ldisc drivers/char/tty_io.c
--- a/drivers/char/tty_io.c~add-receive_room-flow-control-to-flush_to_ldisc
+++ a/drivers/char/tty_io.c
@@ -2772,7 +2772,7 @@ static void flush_to_ldisc(void *private
struct tty_struct *tty = (struct tty_struct *) private_;
unsigned long flags;
struct tty_ldisc *disc;
- struct tty_buffer *tbuf;
+ struct tty_buffer *tbuf, *head;
int count;
char *char_buf;
unsigned char *flag_buf;
@@ -2782,21 +2782,33 @@ static void flush_to_ldisc(void *private
return;
spin_lock_irqsave(&tty->buf.lock, flags);
- while((tbuf = tty->buf.head) != NULL) {
- while ((count = tbuf->commit - tbuf->read) != 0) {
- char_buf = tbuf->char_buf_ptr + tbuf->read;
- flag_buf = tbuf->flag_buf_ptr + tbuf->read;
- tbuf->read += count;
+ head = tty->buf.head;
+ if (head != NULL) {
+ tty->buf.head = NULL;
+ for (;;) {
+ count = head->commit - head->read;
+ if (!count) {
+ if (head->next == NULL)
+ break;
+ tbuf = head;
+ head = head->next;
+ tty_buffer_free(tty, tbuf);
+ continue;
+ }
+ if (!tty->receive_room) {
+ schedule_delayed_work(&tty->buf.work, 1);
+ break;
+ }
+ if (count > tty->receive_room)
+ count = tty->receive_room;
+ char_buf = head->char_buf_ptr + head->read;
+ flag_buf = head->flag_buf_ptr + head->read;
+ head->read += count;
spin_unlock_irqrestore(&tty->buf.lock, flags);
disc->receive_buf(tty, char_buf, flag_buf, count);
spin_lock_irqsave(&tty->buf.lock, flags);
}
- if (tbuf->active)
- break;
- tty->buf.head = tbuf->next;
- if (tty->buf.head == NULL)
- tty->buf.tail = NULL;
- tty_buffer_free(tty, tbuf);
+ tty->buf.head = head;
}
spin_unlock_irqrestore(&tty->buf.lock, flags);
_
Patches currently in -mm which might be from paulkf@xxxxxxxxxxxxx are
origin.patch
remove-dead-entry-in-net-wan-kconfig.patch
more-tty-cleanups-in-drivers-char.patch
fix-memory-leak-in-rocketport-rp_do_receive.patch
add-synclink_gt-custom-hdlc-idle.patch
add-synclink_gt-crc-return-feature.patch
fix-synclink_gt-diagnostics-error-reporting.patch
synclink_gt-add-gt2-adapter-support.patch
remove-tty_dont_flip.patch
add-receive_room-flow-control-to-flush_to_ldisc.patch
revert-tty-buffering-comment-out-debug-code.patch
-
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