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SubjectRe: Locking in the clk API, part 2: clk_prepare/clk_unprepare
On Tue, Feb 01, 2011 at 04:53:44PM +0100, Uwe Kleine-König wrote:
> On Tue, Feb 01, 2011 at 03:24:58PM +0000, Russell King - ARM Linux wrote:
> > On Tue, Feb 01, 2011 at 04:18:46PM +0100, Uwe Kleine-König wrote:
> > > yeah, didn't thought about multiple consumers, so (as Jeremy suggested)
> > > the right thing is to sleep until CLK_BUSY is cleared.
> >
> > A simpler way to write this is:
> >
> > int clk_prepare(struct clk *clk)
> > {
> > int ret = 0;
> >
> > mutex_lock(&clk->mutex);
> > if (clk->prepared == 0)
> > ret = clk->ops->prepare(clk);
> > if (ret == 0)
> > clk->prepared++;
> > mutex_unlock(&clk->mutex);
> >
> > return ret;
> > }
> But you cannot call this in atomic context when you know the clock is
> already prepared.

So? You're not _supposed_ to call it from any atomic context ever.
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