Re: [PATCH 01/48] clk: at91: replace usleep() by udelay() calls

[Afzal Mohammed]

Hi,

On Mon, Jun 13, 2016 at 05:24:09PM +0200, Alexandre Belloni wrote:
> On 11/06/2016 at 00:30:36 +0200, Arnd Bergmann wrote :

> > Does this have to be called that early? It seems wasteful to always
> > call udelay() here, when these are functions that are normally
> > allowed to sleep.

> So I've tested it and something like that would work:
> 
> 	if (system_state < SYSTEM_RUNNING)
> 		udelay(osc->startup_usec);
> 	else
> 		usleep_range(osc->startup_usec, osc->startup_usec + 1);
> 
> But I'm afraid it would be the first driver to actually do something
> like that (however, it is already the only driver trying to sleep). 

tglx has suggested to modify clock core to handle a somewhat similar
kind of scenario (probably should work here too) and avoid driver
changes,

http://lkml.kernel.org/r/alpine.DEB.2.11.1606061448010.28031@nanos

Regards
afzal