Re: [PATCH] CDROM: replace jiffies busyloop with msleep

From: Ingo Molnar
Date: Tue May 22 2007 - 07:22:19 EST



* Jeff Garzik <jeff@xxxxxxxxxx> wrote:

> >@@ -1709,12 +1710,11 @@ static int __init sjcd_init(void)
> > printk(KERN_INFO "SJCD: Resetting: ");
> > sjcd_send_cmd(SCMD_RESET);
> > for (i = 1000; i > 0 && !sjcd_status_valid; --i) {
> >- unsigned long timer;
> >-
> > /*
> > * Wait 10ms approx.
> > */
> >- for (timer = jiffies; time_before_eq(jiffies, timer););
> >+ msleep(10);
> >+
>
> I always worry when I see code like this, wondering if there is some
> arcane reason that I cannot fathom, that is being removed. You gotta
> wonder how long it has been since this driver was used, by anybody.
>
> Oh well, I cannot find fault with the patch, paranoia worries aside.

well, while i dont have that hardware, i found this by booting an
allyesconfig bzImage which runs the code above, which locks up without
this change. And then it booted fine with this change. So arcane issues
aside, it does visibly improve things ;-)

Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/