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From:   Bartosz Golaszewski <brgl@bgdev.pl>
To:     Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Junxiao Chang <junxiao.chang@intel.com>
Cc:     netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [PATCH net] net: stmmac: fix double serdes powerdown
Date:   Wed, 21 Jun 2023 15:55:37 +0200
Message-Id: <20230621135537.376649-1-brgl@bgdev.pl>
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From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Commit 49725ffc15fc ("net: stmmac: power up/down serdes in
stmmac_open/release") correctly added a call to the serdes_powerdown()
callback to stmmac_release() but did not remove the one from
stmmac_remove() which leads to a doubled call to serdes_powerdown().

This can lead to all kinds of problems: in the case of the qcom ethqos
driver, it caused an unbalanced regulator disable splat.

Fixes: 49725ffc15fc ("net: stmmac: power up/down serdes in stmmac_open/release")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 10e8a5606ba6..4727f7be4f86 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7461,12 +7461,6 @@ void stmmac_dvr_remove(struct device *dev)
 	netif_carrier_off(ndev);
 	unregister_netdev(ndev);
 
-	/* Serdes power down needs to happen after VLAN filter
-	 * is deleted that is triggered by unregister_netdev().
-	 */
-	if (priv->plat->serdes_powerdown)
-		priv->plat->serdes_powerdown(ndev, priv->plat->bsp_priv);
-
 #ifdef CONFIG_DEBUG_FS
 	stmmac_exit_fs(ndev);
 #endif
-- 
2.39.2