summaryrefslogtreecommitdiffstats
path: root/drivers/tty
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/n_gsm.c6
-rw-r--r--drivers/tty/n_hdlc.c18
-rw-r--r--drivers/tty/n_r3964.c10
-rw-r--r--drivers/tty/n_tty.c61
-rw-r--r--drivers/tty/tty_buffer.c27
-rw-r--r--drivers/tty/vt/selection.c3
6 files changed, 70 insertions, 55 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index a4c42a75a3b..09e8c7d53af 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2128,8 +2128,8 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
gsm->tty = NULL;
}
-static unsigned int gsmld_receive_buf(struct tty_struct *tty,
- const unsigned char *cp, char *fp, int count)
+static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
{
struct gsm_mux *gsm = tty->disc_data;
const unsigned char *dp;
@@ -2162,8 +2162,6 @@ static unsigned int gsmld_receive_buf(struct tty_struct *tty,
}
/* FASYNC if needed ? */
/* If clogged call tty_throttle(tty); */
-
- return count;
}
/**
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index cac666314ae..cea56033b34 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -188,8 +188,8 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
poll_table *wait);
static int n_hdlc_tty_open(struct tty_struct *tty);
static void n_hdlc_tty_close(struct tty_struct *tty);
-static unsigned int n_hdlc_tty_receive(struct tty_struct *tty,
- const __u8 *cp, char *fp, int count);
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp,
+ char *fp, int count);
static void n_hdlc_tty_wakeup(struct tty_struct *tty);
#define bset(p,b) ((p)[(b) >> 5] |= (1 << ((b) & 0x1f)))
@@ -509,8 +509,8 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
* Called by tty low level driver when receive data is available. Data is
* interpreted as one HDLC frame.
*/
-static unsigned int n_hdlc_tty_receive(struct tty_struct *tty,
- const __u8 *data, char *flags, int count)
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
+ char *flags, int count)
{
register struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
register struct n_hdlc_buf *buf;
@@ -521,20 +521,20 @@ static unsigned int n_hdlc_tty_receive(struct tty_struct *tty,
/* This can happen if stuff comes in on the backup tty */
if (!n_hdlc || tty != n_hdlc->tty)
- return -ENODEV;
+ return;
/* verify line is using HDLC discipline */
if (n_hdlc->magic != HDLC_MAGIC) {
printk("%s(%d) line not using HDLC discipline\n",
__FILE__,__LINE__);
- return -EINVAL;
+ return;
}
if ( count>maxframe ) {
if (debuglevel >= DEBUG_LEVEL_INFO)
printk("%s(%d) rx count>maxframesize, data discarded\n",
__FILE__,__LINE__);
- return -EINVAL;
+ return;
}
/* get a free HDLC buffer */
@@ -550,7 +550,7 @@ static unsigned int n_hdlc_tty_receive(struct tty_struct *tty,
if (debuglevel >= DEBUG_LEVEL_INFO)
printk("%s(%d) no more rx buffers, data discarded\n",
__FILE__,__LINE__);
- return -EINVAL;
+ return;
}
/* copy received data to HDLC buffer */
@@ -565,8 +565,6 @@ static unsigned int n_hdlc_tty_receive(struct tty_struct *tty,
if (n_hdlc->tty->fasync != NULL)
kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN);
- return count;
-
} /* end of n_hdlc_tty_receive() */
/**
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
index a4bc39c21a4..5c6c31459a2 100644
--- a/drivers/tty/n_r3964.c
+++ b/drivers/tty/n_r3964.c
@@ -139,8 +139,8 @@ static int r3964_ioctl(struct tty_struct *tty, struct file *file,
static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
struct poll_table_struct *wait);
-static unsigned int r3964_receive_buf(struct tty_struct *tty,
- const unsigned char *cp, char *fp, int count);
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count);
static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
.owner = THIS_MODULE,
@@ -1239,8 +1239,8 @@ static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
return result;
}
-static unsigned int r3964_receive_buf(struct tty_struct *tty,
- const unsigned char *cp, char *fp, int count)
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
{
struct r3964_info *pInfo = tty->disc_data;
const unsigned char *p;
@@ -1257,8 +1257,6 @@ static unsigned int r3964_receive_buf(struct tty_struct *tty,
}
}
-
- return count;
}
MODULE_LICENSE("GPL");
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 95d0a9c2dd1..0ad32888091 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -81,6 +81,38 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
return put_user(x, ptr);
}
+/**
+ * n_tty_set__room - receive space
+ * @tty: terminal
+ *
+ * Called by the driver to find out how much data it is
+ * permitted to feed to the line discipline without any being lost
+ * and thus to manage flow control. Not serialized. Answers for the
+ * "instant".
+ */
+
+static void n_tty_set_room(struct tty_struct *tty)
+{
+ /* tty->read_cnt is not read locked ? */
+ int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
+ int old_left;
+
+ /*
+ * If we are doing input canonicalization, and there are no
+ * pending newlines, let characters through without limit, so
+ * that erase characters will be handled. Other excess
+ * characters will be beeped.
+ */
+ if (left <= 0)
+ left = tty->icanon && !tty->canon_data;
+ old_left = tty->receive_room;
+ tty->receive_room = left;
+
+ /* Did this open up the receive buffer? We may need to flip */
+ if (left && !old_left)
+ schedule_work(&tty->buf.work);
+}
+
static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
{
if (tty->read_cnt < N_TTY_BUF_SIZE) {
@@ -152,6 +184,7 @@ static void reset_buffer_flags(struct tty_struct *tty)
tty->canon_head = tty->canon_data = tty->erasing = 0;
memset(&tty->read_flags, 0, sizeof tty->read_flags);
+ n_tty_set_room(tty);
check_unthrottle(tty);
}
@@ -1327,19 +1360,17 @@ static void n_tty_write_wakeup(struct tty_struct *tty)
* calls one at a time and in order (or using flush_to_ldisc)
*/
-static unsigned int n_tty_receive_buf(struct tty_struct *tty,
- const unsigned char *cp, char *fp, int count)
+static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
{
const unsigned char *p;
char *f, flags = TTY_NORMAL;
int i;
char buf[64];
unsigned long cpuflags;
- int left;
- int ret = 0;
if (!tty->read_buf)
- return 0;
+ return;
if (tty->real_raw) {
spin_lock_irqsave(&tty->read_lock, cpuflags);
@@ -1349,7 +1380,6 @@ static unsigned int n_tty_receive_buf(struct tty_struct *tty,
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
- ret += i;
cp += i;
count -= i;
@@ -1359,10 +1389,8 @@ static unsigned int n_tty_receive_buf(struct tty_struct *tty,
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
- ret += i;
spin_unlock_irqrestore(&tty->read_lock, cpuflags);
} else {
- ret = count;
for (i = count, p = cp, f = fp; i; i--, p++) {
if (f)
flags = *f++;
@@ -1390,6 +1418,8 @@ static unsigned int n_tty_receive_buf(struct tty_struct *tty,
tty->ops->flush_chars(tty);
}
+ n_tty_set_room(tty);
+
if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
L_EXTPROC(tty)) {
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
@@ -1402,12 +1432,8 @@ static unsigned int n_tty_receive_buf(struct tty_struct *tty,
* mode. We don't want to throttle the driver if we're in
* canonical mode and don't have a newline yet!
*/
- left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
-
- if (left < TTY_THRESHOLD_THROTTLE)
+ if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
tty_throttle(tty);
-
- return ret;
}
int is_ignored(int sig)
@@ -1451,6 +1477,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
tty->raw = 1;
tty->real_raw = 1;
+ n_tty_set_room(tty);
return;
}
if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
@@ -1503,6 +1530,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
else
tty->real_raw = 0;
}
+ n_tty_set_room(tty);
/* The termios change make the tty ready for I/O */
wake_up_interruptible(&tty->write_wait);
wake_up_interruptible(&tty->read_wait);
@@ -1784,6 +1812,8 @@ do_it_again:
retval = -ERESTARTSYS;
break;
}
+ /* FIXME: does n_tty_set_room need locking ? */
+ n_tty_set_room(tty);
timeout = schedule_timeout(timeout);
continue;
}
@@ -1855,8 +1885,10 @@ do_it_again:
* longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
* we won't get any more characters.
*/
- if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE)
+ if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
+ n_tty_set_room(tty);
check_unthrottle(tty);
+ }
if (b - buf >= minimum)
break;
@@ -1878,6 +1910,7 @@ do_it_again:
} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
+ n_tty_set_room(tty);
return retval;
}
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 46de2e075da..6c9b7cd6778 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -413,10 +413,8 @@ static void flush_to_ldisc(struct work_struct *work)
spin_lock_irqsave(&tty->buf.lock, flags);
if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
- struct tty_buffer *head, *tail = tty->buf.tail;
- int seen_tail = 0;
+ struct tty_buffer *head;
while ((head = tty->buf.head) != NULL) {
- int copied;
int count;
char *char_buf;
unsigned char *flag_buf;
@@ -425,15 +423,6 @@ static void flush_to_ldisc(struct work_struct *work)
if (!count) {
if (head->next == NULL)
break;
- /*
- There's a possibility tty might get new buffer
- added during the unlock window below. We could
- end up spinning in here forever hogging the CPU
- completely. To avoid this let's have a rest each
- time we processed the tail buffer.
- */
- if (tail == head)
- seen_tail = 1;
tty->buf.head = head->next;
tty_buffer_free(tty, head);
continue;
@@ -443,19 +432,17 @@ static void flush_to_ldisc(struct work_struct *work)
line discipline as we want to empty the queue */
if (test_bit(TTY_FLUSHPENDING, &tty->flags))
break;
+ if (!tty->receive_room)
+ 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);
- copied = disc->ops->receive_buf(tty, char_buf,
+ disc->ops->receive_buf(tty, char_buf,
flag_buf, count);
spin_lock_irqsave(&tty->buf.lock, flags);
-
- head->read += copied;
-
- if (copied == 0 || seen_tail) {
- schedule_work(&tty->buf.work);
- break;
- }
}
clear_bit(TTY_FLUSHING, &tty->flags);
}
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 67b1d0d7c8a..fb864e7fcd1 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -332,7 +332,8 @@ int paste_selection(struct tty_struct *tty)
continue;
}
count = sel_buffer_lth - pasted;
- count = tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
+ count = min(count, tty->receive_room);
+ tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
NULL, count);
pasted += count;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-07 03:06:06 +0000