Ralf Baechle napsal(a):
On Fri, Jul 25, 2008 at 07:49:58PM +0200, Jiri Slaby wrote:
ds1286_get_time(); is not called from atomic context, sleep for 20 ms is
better choice than a (home-made) busy waiting for such a situation.
Looks ok to me I guess. Though I don't really think it matters ...
I think RT people has different opinion ;).
The same condition also appears in drivers/char/rtc.c and maybe a few
others. Rtc.c has been copies and modified several times.
In rtc.c there is something completely different:
while (rtc_is_updating() != 0 &&
time_before(jiffies, uip_watchdog + 2*HZ/100))
cpu_relax();
It's a conditional busy-waiting. It reads the rtc status after each busy
cycle while in the ds1286 there was
if (ds1286_is_updating() != 0)
while (time_before(jiffies, uip_watchdog + 2*HZ/100))
barrier();
