• Ryan Grimm's avatar
    cxl: Fix device_node reference counting · 6f963ec2
    Ryan Grimm authored
    When unbinding and rebinding the driver on a system with a card in PHB0, this
    error condition is reached after a few attempts:
    
    ERROR: Bad of_node_put() on /pciex@3fffe40000000
    CPU: 0 PID: 3040 Comm: bash Not tainted 3.18.0-rc3-12545-g3627ffe #152
    Call Trace:
    [c000000721acb5c0] [c00000000086ef94] .dump_stack+0x84/0xb0 (unreliable)
    [c000000721acb640] [c00000000073a0a8] .of_node_release+0xd8/0xe0
    [c000000721acb6d0] [c00000000044bc44] .kobject_release+0x74/0xe0
    [c000000721acb760] [c0000000007394fc] .of_node_put+0x1c/0x30
    [c000000721acb7d0] [c000000000545cd8] .cxl_probe+0x1a98/0x1d50
    [c000000721acb900] [c0000000004845a0] .local_pci_probe+0x40/0xc0
    [c000000721acb980] [c000000000484998] .pci_device_probe+0x128/0x170
    [c000000721acba30] [c00000000052400c] .driver_probe_device+0xac/0x2a0
    [c000000721acbad0] [c000000000522468] .bind_store+0x108/0x160
    [c000000721acbb70] [c000000000521448] .drv_attr_store+0x38/0x60
    [c000000721acbbe0] [c000000000293840] .sysfs_kf_write+0x60/0xa0
    [c000000721acbc50] [c000000000292500] .kernfs_fop_write+0x140/0x1d0
    [c000000721acbcf0] [c000000000208648] .vfs_write+0xd8/0x260
    [c000000721acbd90] [c000000000208b18] .SyS_write+0x58/0x100
    [c000000721acbe30] [c000000000009258] syscall_exit+0x0/0x98
    
    We are missing a call to of_node_get(). pnv_pci_to_phb_node() should
    call of_node_get() otherwise np's reference count isn't incremented and
    it might go away. Rename pnv_pci_to_phb_node() to pnv_pci_get_phb_node()
    so it's clear it calls of_node_get().
    Signed-off-by: default avatarRyan Grimm <grimm@linux.vnet.ibm.com>
    Acked-by: default avatarIan Munsie <imunsie@au1.ibm.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    6f963ec2
pci.c 29.4 KB