| From foo@baz Thu Jan 12 21:36:14 CET 2017 |
| From: Florian Fainelli <f.fainelli@gmail.com> |
| Date: Tue, 27 Dec 2016 18:23:06 -0800 |
| Subject: net: stmmac: Fix race between stmmac_drv_probe and stmmac_open |
| |
| From: Florian Fainelli <f.fainelli@gmail.com> |
| |
| |
| [ Upstream commit 5701659004d68085182d2fd4199c79172165fa65 ] |
| |
| 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 <hock.leong.kweh@intel.com> |
| Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 22 +++++++++++++--------- |
| 1 file changed, 13 insertions(+), 9 deletions(-) |
| |
| --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |
| +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |
| @@ -2939,12 +2939,6 @@ int stmmac_dvr_probe(struct device *devi |
| 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; |
| - } |
| - |
| /* If a specific clk_csr value is passed from the platform |
| * this means that the CSR Clock Range selection cannot be |
| * changed at run-time and it is fixed. Viceversa the driver'll try to |
| @@ -2969,11 +2963,21 @@ int stmmac_dvr_probe(struct device *devi |
| } |
| } |
| |
| - return 0; |
| + ret = register_netdev(ndev); |
| + if (ret) { |
| + netdev_err(priv->dev, "%s: ERROR %i registering the device\n", |
| + __func__, ret); |
| + goto error_netdev_register; |
| + } |
| + |
| + return ret; |
| |
| -error_mdio_register: |
| - unregister_netdev(ndev); |
| 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: |
| netif_napi_del(&priv->napi); |
| error_hw_init: |
| clk_disable_unprepare(priv->pclk); |