• Shubhrajyoti Datta's avatar
    net: axienet: Fix double deregister of mdio · 653959e0
    Shubhrajyoti Datta authored
    BugLink: https://bugs.launchpad.net/bugs/1792392
    
    [ Upstream commit 03bc7cab ]
    
    If the registration fails then mdio_unregister is called.
    However at unbind the unregister ia attempted again resulting
    in the below crash
    
    [   73.544038] kernel BUG at drivers/net/phy/mdio_bus.c:415!
    [   73.549362] Internal error: Oops - BUG: 0 [#1] SMP
    [   73.554127] Modules linked in:
    [   73.557168] CPU: 0 PID: 2249 Comm: sh Not tainted 4.14.0 #183
    [   73.562895] Hardware name: xlnx,zynqmp (DT)
    [   73.567062] task: ffffffc879e41180 task.stack: ffffff800cbe0000
    [   73.572973] PC is at mdiobus_unregister+0x84/0x88
    [   73.577656] LR is at axienet_mdio_teardown+0x18/0x30
    [   73.582601] pc : [<ffffff80085fa4cc>] lr : [<ffffff8008616858>]
    pstate: 20000145
    [   73.589981] sp : ffffff800cbe3c30
    [   73.593277] x29: ffffff800cbe3c30 x28: ffffffc879e41180
    [   73.598573] x27: ffffff8008a21000 x26: 0000000000000040
    [   73.603868] x25: 0000000000000124 x24: ffffffc879efe920
    [   73.609164] x23: 0000000000000060 x22: ffffffc879e02000
    [   73.614459] x21: ffffffc879e02800 x20: ffffffc87b0b8870
    [   73.619754] x19: ffffffc879e02800 x18: 000000000000025d
    [   73.625050] x17: 0000007f9a719ad0 x16: ffffff8008195bd8
    [   73.630345] x15: 0000007f9a6b3d00 x14: 0000000000000010
    [   73.635640] x13: 74656e7265687465 x12: 0000000000000030
    [   73.640935] x11: 0000000000000030 x10: 0101010101010101
    [   73.646231] x9 : 241f394f42533300 x8 : ffffffc8799f6e98
    [   73.651526] x7 : ffffffc8799f6f18 x6 : ffffffc87b0ba318
    [   73.656822] x5 : ffffffc87b0ba498 x4 : 0000000000000000
    [   73.662117] x3 : 0000000000000000 x2 : 0000000000000008
    [   73.667412] x1 : 0000000000000004 x0 : ffffffc8799f4000
    [   73.672708] Process sh (pid: 2249, stack limit = 0xffffff800cbe0000)
    
    Fix the same by making the bus NULL on unregister.
    Signed-off-by: default avatarShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
    Signed-off-by: default avatarKleber Sacilotto de Souza <kleber.souza@canonical.com>
    653959e0
xilinx_axienet_mdio.c 6.28 KB