>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 <mturque...@baylibre.com>
---
Changed in v2ish:
* s/WARN_ON/WARN_ON_ONCE/ to reduce noise for pm-clocks
drivers/clk/clk.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 01183e3..d81f970 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2824,6 +2824,14 @@ 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_ONCE(clk->prepare_count);
+ WARN_ON_ONCE(clk->enable_count);
+
owner = clk->core->owner;
kref_put(&clk->core->ref, __clk_release);
--
2.1.4
