Re: ath5k: kernel timing screwed - due to unserialised register access?

[Elias Oltmanns <eo@nebensachen.de>]

Thomas Gleixner <tglx@linutronix.de> wrote:
> On Fri, 10 Oct 2008, Elias Oltmanns wrote:
>> That printk() has not been hit, I'm afraid. The output of
>
>> sysrq_timer_list_show() looks much the same but there is no message
>> about softirqs. Just for the record, I've switched to 2.6.27 because I'm
>> debugging something else at the same time, but it doesn't make any
>> difference.
>> 
>> Now, here is another question: There are various snippets like the
>> following in the ath5k driver:
>> 
>> 	/* Wait until the noise floor is calibrated and read the value */
>> 	for (i = 20; i > 0; i--) {
>> 		mdelay(1);
>
> Uurgh. That's broken. mdelay sleeps so this should not be called in
> softirq context.

That was my first thought when I discovered this. However, from what I
read on the web, I somehow got the impression that [um]delay() was
alright as opposed to msleep(). What exactly is the difference then?

Regards,

Elias