• Florian Fainelli's avatar
    net: stmmac: Fix race between stmmac_drv_probe and stmmac_open · 3f284760
    Florian Fainelli authored
    [ Upstream commit 57016590 ]
    
    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: 4bfcbd7a ("stmmac: Move the mdio_register/_unregister in probe/remove")
    Reported-by: default avatarKweh, Hock Leong <hock.leong.kweh@intel.com>
    Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    3f284760
stmmac_main.c 89.2 KB