[PATCH] drivers/char/hvc_console.c: reduce max idle timeout

From: Chris Metcalf
Date: Wed Oct 27 2010 - 13:00:01 EST


The tile architecture uses this framework for our serial console,
and our users complain that the delay of up to two seconds feels like
the machine has gone non-responsive and is disturbing. By contrast,
a delay of up to half a second feels like just the normal sort of
delay caused by swapping, network lag, etc. and is not noticeable.
The overhead is obviously not much greater.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
---

I'm happy to push this via the tile tree if the linuxppc-dev folks
want to give me an acked-by, or you can take it into your tree. Thanks!

drivers/char/hvc_console.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 3afd62e..1df5431 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -565,11 +565,11 @@ static int hvc_chars_in_buffer(struct tty_struct *tty)
* and during console activity we will use a default MIN_TIMEOUT of 10. When
* the console is idle, we increase the timeout value on each pass through
* msleep until we reach the max. This may be noticeable as a brief (average
- * one second) delay on the console before the console responds to input when
+ * 0.25 second) delay on the console before the console responds to input when
* there has been no input for some time.
*/
#define MIN_TIMEOUT (10)
-#define MAX_TIMEOUT (2000)
+#define MAX_TIMEOUT (500)
static u32 timeout = MIN_TIMEOUT;

#define HVC_POLL_READ 0x00000001
--
1.6.5.2

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