[RFC, PATCH 3/3] clk: add warnings for incorrect enable/prepare semantics
From: Uwe Kleine-König <hidden>
Date: 2011-02-07 08:06:08
Also in:
linux-sh, lkml
Hello Jeremy, On Mon, Feb 07, 2011 at 02:07:57PM +0800, Jeremy Kerr wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |