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authorJeff Dike <jdike@addtoit.com>2006-01-06 00:18:58 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 08:33:46 -0800
commite4dcee8099802c71437a15b940f66106d9f88b2f (patch)
treeb4831639d38369fce2e20fd40730425ca702102c /arch/um/drivers/line.c
parent9159c9dfffe1746d58b015ceaa3b7b8e99ee9d5c (diff)
[PATCH] uml: Add throttling to console driver
This patch adds support for throttling and unthrottling input when the tty driver can't handle it. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/drivers/line.c')
-rw-r--r--arch/um/drivers/line.c29
1 files changed, 27 insertions, 2 deletions
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 851a7c8caae..b8e3e800ee4 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -36,8 +36,9 @@ static void line_timer_cb(void *arg)
{
struct line *line = arg;
- chan_interrupt(&line->chan_list, &line->task, line->tty,
- line->driver->read_irq);
+ if(!line->throttled)
+ chan_interrupt(&line->chan_list, &line->task, line->tty,
+ line->driver->read_irq);
}
/* Returns the free space inside the ring buffer of this line.
@@ -340,6 +341,30 @@ int line_ioctl(struct tty_struct *tty, struct file * file,
return ret;
}
+void line_throttle(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ deactivate_chan(&line->chan_list, line->driver->read_irq);
+ line->throttled = 1;
+}
+
+void line_unthrottle(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ line->throttled = 0;
+ chan_interrupt(&line->chan_list, &line->task, tty,
+ line->driver->read_irq);
+
+ /* Maybe there is enough stuff pending that calling the interrupt
+ * throttles us again. In this case, line->throttled will be 1
+ * again and we shouldn't turn the interrupt back on.
+ */
+ if(!line->throttled)
+ reactivate_chan(&line->chan_list, line->driver->read_irq);
+}
+
static irqreturn_t line_write_interrupt(int irq, void *data,
struct pt_regs *unused)
{