Messages in this thread | | | Date | Mon, 7 Feb 2011 09:05:55 +0100 | From | Uwe Kleine-König <> | Subject | Re: [RFC, PATCH 3/3] clk: add warnings for incorrect enable/prepare semantics |
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Hello Jeremy,
On Mon, Feb 07, 2011 at 02:07:57PM +0800, Jeremy Kerr wrote: > This change adds warnings to check for: > > 1) enabling a clock that hasn't been prepared; and > > 2) unpreparing a clock that is still enabled > > While the correctness can't be guaranteed, these warnings should cover > most situations. > > Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com> > > --- > drivers/clk/clk.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 51dbd33..2369959 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -35,6 +35,8 @@ void clk_unprepare(struct clk *clk) > if (!clk->ops->unprepare) > return; > > + WARN_ON(clk->enable_count); > + > mutex_lock(&clk->prepare_lock); > if (--clk->prepare_count == 0) > clk->ops->unprepare(clk); > @@ -50,6 +52,8 @@ int clk_enable(struct clk *clk) > if (!clk->ops->enable) > return 0; > > + WARN_ON(clk->ops->prepare && clk->prepare_count); > + This implies the warning is only issued on clocks that have a prepare callback. If we want to enforce the new API the warning here shouldn't depend on clk->ops->prepare. (clk_prepare and clk_unprepare need to be changed then to adapt the prepare_count even in the absence of clk->ops->prepare.)
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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