Re: [PATCH v3 1/2] mmc: Move mmc_delay() to include/linux/mmc/core.h

On 09/21/2012 08:33 AM, Arnd Bergmann wrote:

On Friday 21 September 2012, Chunhe Lan wrote:

quoted

On 08/10/2012 09:27 AM, Arnd Bergmann wrote:

quoted

On Friday 10 August 2012, Chunhe Lan wrote:

       cond_resched();
       mdelay(ms);

sets off alarm bells, and I would always replace that with msleep().

      I think that it does not replace with msleep().
      When the time of sleep is very short, program should not been scheduled
      in the context. Because it expends the more time.

A time measured in miliseconds is never "very short" for the scheduler,
a lot of things can happen during that time span. The code I quoted
also does not care too much about accuracy, otherwise it would adapt
the time in the mdelay based on whether the cond_resched() actually
schedules to another thread.

   OK. As you have mentioned, it would been modified to such:

static inline void mmc_delay(unsigned int ms)
{
        if (ms < 1000 / HZ) {
                cond_resched();
                msleep(ms);
        } else {
                msleep(ms);
        }
}

OR such:

static inline void mmc_delay(unsigned int ms)
{
                msleep(ms);
}

OR other code?

Thanks,
Chunhe

	Arnd