[PATCH 2/7] net: stmmac: Balance PTP reference clock enable/disable

From: Thierry Reding
Date: Thu Feb 23 2017 - 12:26:37 EST


From: Thierry Reding <treding@xxxxxxxxxx>

clk_prepare_enable() and clk_disable_unprepare() for this clock aren't
properly balanced, which can trigger a WARN_ON() in the common clock
framework.

Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++++
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 -
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3cbe09682afe..6b7a5ce19589 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1711,6 +1711,10 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
stmmac_mmc_setup(priv);

if (init_ptp) {
+ ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
+ if (ret < 0)
+ netdev_warn(priv->dev, "failed to enable PTP reference clock: %d\n", ret);
+
ret = stmmac_init_ptp(priv);
if (ret == -EOPNOTSUPP)
netdev_warn(priv->dev, "PTP not supported by HW\n");
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 5b18355c0d2b..d285d6cfbd0d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -365,7 +365,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
plat->clk_ptp_ref = NULL;
dev_warn(&pdev->dev, "PTP uses main clock\n");
} else {
- clk_prepare_enable(plat->clk_ptp_ref);
plat->clk_ptp_rate = clk_get_rate(plat->clk_ptp_ref);
dev_dbg(&pdev->dev, "PTP rate %d\n", plat->clk_ptp_rate);
}
--
2.11.1