Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbdFHAPy (ORCPT ); Wed, 7 Jun 2017 20:15:54 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50088 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751922AbdFGXCE (ORCPT ); Wed, 7 Jun 2017 19:02:04 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Florian Fainelli , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 074/250] net: stmmac: Fix race between stmmac_drv_probe and stmmac_open Date: Thu, 8 Jun 2017 00:57:40 +0200 Message-Id: <1496876436-32402-75-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1496876436-32402-1-git-send-email-w@1wt.eu> References: <1496876436-32402-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3598 Lines: 89 From: Florian Fainelli commit 5701659004d68085182d2fd4199c79172165fa65 upstream. There is currently a small window during which the network device registered by stmmac can be made visible, yet all resources, including and clock and MDIO bus have not had a chance to be set up, this can lead to the following error to occur: [ 473.919358] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized): stmmac_dvr_probe: warning: cannot get CSR clock [ 473.919382] stmmaceth 0000:01:00.0: no reset control found [ 473.919412] stmmac - user ID: 0x10, Synopsys ID: 0x42 [ 473.919429] stmmaceth 0000:01:00.0: DMA HW capability register supported [ 473.919436] stmmaceth 0000:01:00.0: RX Checksum Offload Engine supported [ 473.919443] stmmaceth 0000:01:00.0: TX Checksum insertion supported [ 473.919451] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized): Enable RX Mitigation via HW Watchdog Timer [ 473.921395] libphy: PHY stmmac-1:00 not found [ 473.921417] stmmaceth 0000:01:00.0 eth0: Could not attach to PHY [ 473.921427] stmmaceth 0000:01:00.0 eth0: stmmac_open: Cannot attach to PHY (error: -19) [ 473.959710] libphy: stmmac: probed [ 473.959724] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 0 IRQ POLL (stmmac-1:00) active [ 473.959728] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 1 IRQ POLL (stmmac-1:01) [ 473.959731] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 2 IRQ POLL (stmmac-1:02) [ 473.959734] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 3 IRQ POLL (stmmac-1:03) Fix this by making sure that register_netdev() is the last thing being done, which guarantees that the clock and the MDIO bus are available. Fixes: 4bfcbd7abce2 ("stmmac: Move the mdio_register/_unregister in probe/remove") Reported-by: Kweh, Hock Leong Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index e9eab29..5cb09ec 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2697,12 +2697,6 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device, spin_lock_init(&priv->lock); spin_lock_init(&priv->tx_lock); - ret = register_netdev(ndev); - if (ret) { - pr_err("%s: ERROR %i registering the device\n", __func__, ret); - goto error_netdev_register; - } - priv->stmmac_clk = clk_get(priv->device, STMMAC_RESOURCE_NAME); if (IS_ERR(priv->stmmac_clk)) { pr_warn("%s: warning: cannot get CSR clock\n", __func__); @@ -2733,13 +2727,23 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device, } } + ret = register_netdev(ndev); + if (ret) { + netdev_err(priv->dev, "%s: ERROR %i registering the device\n", + __func__, ret); + goto error_netdev_register; + } + return priv; +error_netdev_register: + if (priv->pcs != STMMAC_PCS_RGMII && + priv->pcs != STMMAC_PCS_TBI && + priv->pcs != STMMAC_PCS_RTBI) + stmmac_mdio_unregister(ndev); error_mdio_register: clk_put(priv->stmmac_clk); error_clk_get: - unregister_netdev(ndev); -error_netdev_register: netif_napi_del(&priv->napi); error_free_netdev: free_netdev(ndev); -- 2.8.0.rc2.1.gbe9624a