Re: [PATCH 30/39] sound/vx_core: replace schedule_timeout() with msleep()

Re: [PATCH 30/39] sound/vx_core: replace schedule_timeout() with msleep()

[Takashi Iwai]

At Fri, 21 Jan 2005 11:47:31 -0800,
Nishanth Aravamudan wrote:
> 
> Hi,
> 
> Please consider applying.
> 
> Description: Use msleep() instead of schedule_timeout() to guarantee the task
> delays as expected. The check for xmsec >= 1000 / HZ seems wrong to me, as well,
> since if HZ==100, that means we could mdelay() for 9 msecs!

Yes, and that's intentional.  Originally there were places to call
like snd_vx_delay(1) for just 1 or 2 ms in a long loop.  The loop
calls schedule() occasionally to take control back.
So, we didn't want to do schedule_timeout(1) for HZ=100 in such a
case.  This results in 10 times longer loop execution.

>  msleep() should be
> usable in all cases when not in an interrupt handler.

I agree in general, but, msleep() isn't always a replacement of
mdelay() if the delay time really matters.


Takashi


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[PATCH 30/39] sound/vx_core: replace schedule_timeout() with msleep()

[Nishanth Aravamudan]

Hi,

Please consider applying.

Description: Use msleep() instead of schedule_timeout() to guarantee the task
delays as expected. The check for xmsec >= 1000 / HZ seems wrong to me, as well,
since if HZ==100, that means we could mdelay() for 9 msecs! msleep() should be
usable in all cases when not in an interrupt handler.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>

--- 2.6.11-rc1-kj-v/sound/drivers/vx/vx_core.c	2005-01-15 16:55:45.000000000 -0800
+++ 2.6.11-rc1-kj/sound/drivers/vx/vx_core.c	2005-01-18 13:26:06.000000000 -0800
@@ -45,9 +45,8 @@ MODULE_LICENSE("GPL");
  */
 void snd_vx_delay(vx_core_t *chip, int xmsec)
 {
-	if (! in_interrupt() && xmsec >= 1000 / HZ) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule_timeout((xmsec * HZ + 999) / 1000);
+	if (!in_interrupt()) {
+		msleep(xmsec);
 	} else {
 		mdelay(xmsec);
 	}


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