2005-03-19 13:17:27

by Domen Puncer

Subject: [patch 01/10] char/ds1620: use msleep() instead of schedule_timeout()

Not sure why any driver needs to sleep for *two* ticks, so let's fix it.

Use msleep() instead of schedule_timeout() to guarantee the
task delays as expected. Signals are never checked for by the callers or
in the function itself, so use TASK_UNINTERRUPTIBLE instead of
TASK_INTERRUPTIBLE. The delay is presumed to have been written when HZ==100,
and thus has been multiplied by 10 to pass to msleep().

Signed-off-by: Nishanth Aravamudan <[email protected]>
Signed-off-by: Domen Puncer <[email protected]>
---


kj-domen/drivers/char/ds1620.c | 3 +--
1 files changed, 1 insertion(+), 2 deletions(-)

diff -puN drivers/char/ds1620.c~msleep-drivers_char_ds1620 drivers/char/ds1620.c
--- kj/drivers/char/ds1620.c~msleep-drivers_char_ds1620 2005-03-18 20:05:09.000000000 +0100
+++ kj-domen/drivers/char/ds1620.c 2005-03-18 20:05:09.000000000 +0100
@@ -163,8 +163,7 @@ static void ds1620_out(int cmd, int bits
netwinder_ds1620_reset();
netwinder_unlock(&flags);

- set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(2);
+ msleep(20);
}

static unsigned int ds1620_in(int cmd, int bits)
_

2005-03-19 19:36:02

by Russell King

Subject: Re: [patch 01/10] char/ds1620: use msleep() instead of schedule_timeout()

On Sat, Mar 19, 2005 at 02:17:15PM +0100, [email protected] wrote:
> Not sure why any driver needs to sleep for *two* ticks, so let's fix it.
>
> Use msleep() instead of schedule_timeout() to guarantee the
> task delays as expected. Signals are never checked for by the callers or
> in the function itself, so use TASK_UNINTERRUPTIBLE instead of
> TASK_INTERRUPTIBLE. The delay is presumed to have been written when HZ==100,
> and thus has been multiplied by 10 to pass to msleep().
>
> Signed-off-by: Nishanth Aravamudan <[email protected]>
> Signed-off-by: Domen Puncer <[email protected]>

Acked-by: Russell King <[email protected]>

> ---
>
>
> kj-domen/drivers/char/ds1620.c | 3 +--
> 1 files changed, 1 insertion(+), 2 deletions(-)
>
> diff -puN drivers/char/ds1620.c~msleep-drivers_char_ds1620 drivers/char/ds1620.c
> --- kj/drivers/char/ds1620.c~msleep-drivers_char_ds1620 2005-03-18 20:05:09.000000000 +0100
> +++ kj-domen/drivers/char/ds1620.c 2005-03-18 20:05:09.000000000 +0100
> @@ -163,8 +163,7 @@ static void ds1620_out(int cmd, int bits
> netwinder_ds1620_reset();
> netwinder_unlock(&flags);
>
> - set_current_state(TASK_INTERRUPTIBLE);
> - schedule_timeout(2);
> + msleep(20);
> }
>
> static unsigned int ds1620_in(int cmd, int bits)
> _
> -
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--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core