On Wed, Sep 18, 2013 at 04:18:56PM -0700, Joe Perches wrote: > On Wed, 2013-09-18 at 16:09 -0700, Sören Brinkmann wrote: > > On Wed, Sep 18, 2013 at 04:02:41PM -0700, Joe Perches wrote: > > > On Wed, 2013-09-18 at 15:43 -0700, Soren Brinkmann wrote: > > > > Add a driver for SILabs 570, 571, 598, 599 programmable oscillators. > > > > The devices generate low-jitter clock signals and are reprogrammable via > > > > an I2C interface. > > > [] > > > > v2: > > > [] > > > > - use 10000 as MIN and MAX value in usleep_range > > > [] > > > > diff --git a/drivers/clk/clk-si570.c b/drivers/clk/clk-si570.c > > > [] > > > > +static int si570_set_frequency(struct clk_si570 *data, unsigned long frequency) > > > > +{ > > > [] > > > > + /* Applying a new frequency can take up to 10ms */ > > > > + usleep_range(10000, 10000); > > > > > > Generally it's nicer to have an actual range for usleep_range. > > Well, as I said in the discussion with Guenther. I'm flexible and nobody > > objected when I said to make both equal. A real range doesn't make sense > > here though, but I don't know what's common practice for cases like > > this. > > udelay is normal, but I guess you don't need atomic context. After checkpatch correcting me a few times I went with what Documentation/timers/timers-howto.txt suggests. But yes, then we have this situation, that I want to sleep 10ms, but not longer using a *_range function. I guess it is very application specific whether a longer delay here is acceptable or not. > > > > Is there a bit you could periodically poll to see > > > if the new frequency has been set or is stable so > > > that a 10ms delay isn't always used? > > > Unfortunately not. > > Thanks. I suppose I should read the datasheets before asking. > > http://www.silabs.com/Support%20Documents/TechnicalDocs/si570.pdf > (page 12) > > Anyway, perhaps si570_set_frequency_small needs a delay too.' > > The 570 datasheet says it needs a 100uS delay. You're right. I'll add a delay there as well. The 'rang' question applies here as well. Sören -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html