On 12/22/2012 03:39 AM, Arnd Bergmann wrote:
On Friday 21 December 2012, Chunhe Lan wrote:
+static inline void mmc_delay(unsigned int ms)
+{
+ ktime_t end = ktime_add_us(ktime_get(), ms * 1000);
+
+ while (1) {
+ s64 remaining;
+
+ cond_resched();
+ remaining = ktime_to_us(ktime_sub(end, ktime_get()));
+ if (remaining < 0)
+ break;
+
+ udelay(min_t(u32, remaining, 100));
+ }
+}
The new logic is more accurate than the old one, but it still wastes
a lot of energy and CPU cycles. Could you perhaps use an hrtimer to
set the exact timeout and actually sleep?
I think that does not have to use hrtimer, and it makes a fuss.
And mmc structure has not included the hrtimer variable.
Thanks,
Chunhe
Arnd
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