[PATCH v3 04/13] net: ethernet: ti: cpts: fix unbalanced clk api usage in cpts_register/unregister

From: Grygorii Strashko
Date: Fri Dec 02 2016 - 15:32:24 EST


There are two issues with TI CPTS code which are reproducible when TI
CPSW ethX device passes few up/down iterations:
- cpts refclk prepare counter continuously incremented after each
up/down iteration;
- devm_clk_get(dev, "cpts") is called many times.

Hence, fix these issues by using clk_disable_unprepare() in
cpts_clk_release() and skipping devm_clk_get() if cpts refclk has been
acquired already.

Acked-by: Richard Cochran <richardcochran@xxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/net/ethernet/ti/cpts.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 8cb0369..61198f1 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -230,18 +230,20 @@ static void cpts_overflow_check(struct work_struct *work)

static void cpts_clk_init(struct device *dev, struct cpts *cpts)
{
- cpts->refclk = devm_clk_get(dev, "cpts");
- if (IS_ERR(cpts->refclk)) {
- dev_err(dev, "Failed to get cpts refclk\n");
- cpts->refclk = NULL;
- return;
+ if (!cpts->refclk) {
+ cpts->refclk = devm_clk_get(dev, "cpts");
+ if (IS_ERR(cpts->refclk)) {
+ dev_err(dev, "Failed to get cpts refclk\n");
+ cpts->refclk = NULL;
+ return;
+ }
}
clk_prepare_enable(cpts->refclk);
}

static void cpts_clk_release(struct cpts *cpts)
{
- clk_disable(cpts->refclk);
+ clk_disable_unprepare(cpts->refclk);
}

static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
--
2.10.1