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Date: Fri, 7 Aug 2015 12:09:29 -0700 From: Michael Turquette <mturquette@...libre.com> To: linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org Cc: sboyd@...eaurora.org, lee.jones@...aro.org, maxime.ripard@...e-electrons.com, s.hauer@...gutronix.de, geert@...ux-m68k.org, Michael Turquette <mturquette@...libre.com> Subject: [PATCH RFC RFT 2/3] clk: clk_put WARNs if user has not disabled clk >From the clk_put kerneldoc in include/linux/clk.h: """ Note: drivers must ensure that all clk_enable calls made on this clock source are balanced by clk_disable calls prior to calling this function. """ The common clock framework implementation of the clk.h api has per-user reference counts for calls to clk_prepare and clk_disable. As such it can enforce the requirement to properly call clk_disable and clk_unprepare before calling clk_put. Because this requirement is probably violated in many places, this patch starts with a simple warning. Once offending code has been fixed this check could additionally release the reference counts automatically. Signed-off-by: Michael Turquette <mturquette@...libre.com> --- drivers/clk/clk.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 72feee9..6ec0f77 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2764,6 +2764,14 @@ void __clk_put(struct clk *clk) clk->max_rate < clk->core->req_rate) clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + /* + * before calling clk_put, all calls to clk_prepare and clk_enable from + * a given user must be balanced with calls to clk_disable and + * clk_unprepare by that same user + */ + WARN_ON(clk->prepare_count); + WARN_ON(clk->enable_count); + owner = clk->core->owner; kref_put(&clk->core->ref, __clk_release); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.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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