net: stmmac: fix unbalanced ptp clock issue in suspend/resume flow

BugLink: https://bugs.launchpad.net/bugs/1988479
[ Upstream commit f4c7d8948e866918d61493264dbbd67e45ef2bda ]

Current stmmac driver will prepare/enable ptp_ref clock in
stmmac_init_tstamp_counter().

The stmmac_pltfr_noirq_suspend will disable it once in suspend flow.

But in resume flow,
	stmmac_pltfr_noirq_resume --> stmmac_init_tstamp_counter
	stmmac_resume --> stmmac_hw_setup --> stmmac_init_ptp --> stmmac_init_tstamp_counter
ptp_ref clock reference counter increases twice, which leads to unbalance
ptp clock when resume back.

Move ptp_ref clock prepare/enable out of stmmac_init_tstamp_counter to fix it.

Fixes: 0735e639f129d ("net: stmmac: skip only stmmac_ptp_register when resume from suspend")
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 95e1307cfda2d152e2cd06ba30d7167aa590a18b..b4f83c86556840e805da9e26cb92a8520831107a 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -844,19 +844,10 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags)
        struct timespec64 now;
        u32 sec_inc = 0;
        u64 temp = 0;
-       int ret;
 
        if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
                return -EOPNOTSUPP;
 
-       ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
-       if (ret < 0) {
-               netdev_warn(priv->dev,
-                           "failed to enable PTP reference clock: %pe\n",
-                           ERR_PTR(ret));
-               return ret;
-       }
-
        stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags);
        priv->systime_flags = systime_flags;
 
@@ -3325,6 +3316,14 @@ static int stmmac_hw_setup(struct net_device *dev, bool ptp_register)
 
        stmmac_mmc_setup(priv);
 
+       if (ptp_register) {
+               ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
+               if (ret < 0)
+                       netdev_warn(priv->dev,
+                                   "failed to enable PTP reference clock: %pe\n",
+                                   ERR_PTR(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 11e1055e8260f49962ca88271337eb022b3fa3c5..9f5cac4000da680d061c37171817fb8642abee55 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -815,7 +815,13 @@ static int __maybe_unused stmmac_pltfr_noirq_resume(struct device *dev)
                if (ret)
                        return ret;
 
-               stmmac_init_tstamp_counter(priv, priv->systime_flags);
+               ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
+               if (ret < 0) {
+                       netdev_warn(priv->dev,
+                                   "failed to enable PTP reference clock: %pe\n",
+                                   ERR_PTR(ret));
+                       return ret;
+               }
        }
 
        return 0;