pinctrl: sirf: fix kernel panic in gpio_lock_as_irq

pinctrl: sirf: fix kernel panic in gpio_lock_as_irq

commit 655dada6277991 causes kernel panic, this patch fixes it.

    [    1.197816] [ffffffee] *pgd=0d7fd821, *pte=00000000, *ppte=00000000
    [    1.204070] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
    [    1.209447] Modules linked in:
    [    1.212490] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0-rc1 #3
    [    1.218737] task: cd03c000 ti: cd040000 task.ti: cd040000
    [    1.224127] PC is at gpiod_lock_as_irq+0xc/0x64
    [    1.228634] LR is at sirfsoc_gpio_irq_startup+0x18/0x44
    [    1.233842] pc : [<c01d3990>]    lr : [<c01d1c38>]    psr: a0000193
    [    1.233842] sp : cd041d30  ip : 00000000  fp : 00000000
    [    1.245296] r10: 00000000  r9 : cd023db4  r8 : 60000113
    [    1.250505] r7 : 0000003e  r6 : cd023dd4  r5 : c06bfa54  r4 : cd023d80
    [    1.257014] r3 : 00000020  r2 : 00000000  r1 : ffffffea  r0 : ffffffea
    [    1.263526] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    [    1.270903] Control: 10c53c7d  Table: 00004059  DAC: 00000015
    [    1.276631] Process swapper/0 (pid: 1, stack limit = 0xcd040240)
    [    1.282620] Stack: (0xcd041d30 to 0xcd042000)
    [    1.286963] 1d20:                                     cd023d80 c01d1c38 c01d1c20 cd023d80
    [    1.295124] 1d40: 00000001 c0068438 cd023d80 ccb6d880 cd023dd4 c0067044 0000718e c006719c
    [    1.286963] 1d20:                                     cd023d80 c01d1c38 c01d1c20 cd023d80
    [    1.295124] 1d40: 00000001 c0068438 cd023d80 ccb6d880 cd023dd4 c0067044 0000718e c006719c
    [    1.295124] 1d40: 00000001 c0068438 cd023d80 ccb6d880 cd023dd4 c0067044 0000718e c006719c
    [    1.303283] 1d60: 00000800 00000083 ccb6d880 cd023d80 c02b41d8 00000083 0000003e ccb7c410
    [    1.311442] 1d80: 00000000 c00671dc 00000083 0000003e c02b41d8 cd3dd5c0 0000003e ccb7c634
    [    1.319601] 1da0: cd040030 c00672a8 cd3dd5c0 ccb7c410 ccb6d340 ccb7c410 ccb6d340 cd3dd400
    [    1.327760] 1dc0: cd3dd410 c02b4434 ccb7c410 c01265a8 00000001 cd3dd410 c0687108 00000000
    [    1.335919] 1de0: c0687108 00000000 00000000 c0240170 c0240158 cd3dd410 c06c30d0 c023e8bc
    [    1.344079] 1e00: c023e9d4 00000000 cd3dd410 c023e9d4 c0682150 c023cf88 cd003e98 cd2d50c4
    [    1.352238] 1e20: cd3dd410 cd3dd444 c06822f0 c023e768 cd3dd418 cd3dd410 c06822f0 c023de14
    [    1.360397] 1e40: cd3dd418 00000000 cd3dd410 c023c398 cd041e78 cd041ea8 cd3dd400 cd3dd410
    [    1.368556] 1e60: 00000083 00000000 cd3dd400 cd3dd410 00000083 000000c8 c04e00c8 c023fee8
    [    1.376715] 1e80: 00000000 cd041ea8 cd3dd400 00000001 00000083 c024048c c0435ef8 c0434dec
    [    1.384874] 1ea0: c068da58 c04c6d04 c0682150 c0435ef8 ffffffff 00000000 00000000 c068da58
    [    1.393033] 1ec0: 00000020 00000000 00000000 00000000 c05dabb8 00000007 c068d640 c068d640
    [    1.401193] 1ee0: c04c247c c04c249c 00000000 c00088e8 cd004c00 c043bbb8 cd029180 c03812a0
    [    1.409352] 1f00: 00000000 00000000 60000113 c0673728 60000113 c0673728 00000000 00000000
    [    1.417511] 1f20: cd7fce01 c0390a54 00000065 c003a81c c049e8bc 00000007 cd7fce0e 00000007
    [    1.425670] 1f40: 00000000 c05dabb8 00000007 c068d640 c068d640 c04c050c c04e00c8 00000065
    [    1.433829] 1f60: c04e00c0 c04c0c54 00000007 00000007 c04c050c c037d8fc cd03c000 c004322c
    [    1.441988] 1f80: c0662b40 0000d640 c03737c0 00000000 00000000 00000000 00000000 00000000
    [    1.450147] 1fa0: 00000000 c03737cc 00000000 c000e478 00000000 00000000 00000000 00000000
    [    1.458307] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
    [    1.466467] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 0002d481 05014092
    [    1.474640] [<c01d3990>] (gpiod_lock_as_irq) from [<c01d1c38>] (sirfsoc_gpio_irq_startup+0x18/0x44)
    [    1.483661] [<c01d1c38>] (sirfsoc_gpio_irq_startup) from [<c0068438>] (irq_startup+0x34/0x6c)
    [    1.492163] [<c0068438>] (irq_startup) from [<c0067044>] (__setup_irq+0x450/0x4b8)
    [    1.499714] [<c0067044>] (__setup_irq) from [<c00671dc>] (request_threaded_irq+0xa8/0x128)
    [    1.507960] [<c00671dc>] (request_threaded_irq) from [<c00672a8>] (request_any_context_irq+0x4c/0x7c)
    [    1.517164] [<c00672a8>] (request_any_context_irq) from [<c02b4434>] (gpio_extcon_probe+0x144/0x1d4)
    [    1.526279] [<c02b4434>] (gpio_extcon_probe) from [<c0240170>] (platform_drv_probe+0x18/0x48)
    [    1.534783] [<c0240170>] (platform_drv_probe) from [<c023e8bc>] (driver_probe_device+0x120/0x238)
    [    1.543641] [<c023e8bc>] (driver_probe_device) from [<c023cf88>] (bus_for_each_drv+0x58/0x8c)
    [    1.552143] [<c023cf88>] (bus_for_each_drv) from [<c023e768>] (device_attach+0x74/0x88)
    [    1.560126] [<c023e768>] (device_attach) from [<c023de14>] (bus_probe_device+0x84/0xa8)
    [    1.568113] [<c023de14>] (bus_probe_device) from [<c023c398>] (device_add+0x440/0x520)
    [    1.576012] [<c023c398>] (device_add) from [<c023fee8>] (platform_device_add+0xb4/0x214)
    [    1.584084] [<c023fee8>] (platform_device_add) from [<c024048c>] (platform_device_register_full+0xb8/0xdc)
    [    1.593719] [<c024048c>] (platform_device_register_full) from [<c04c6d04>] (sirfsoc_init_late+0xec/0xf4)
    [    1.603185] [<c04c6d04>] (sirfsoc_init_late) from [<c04c249c>] (init_machine_late+0x20/0x28)
    [    1.611603] [<c04c249c>] (init_machine_late) from [<c00088e8>] (do_one_initcall+0xf8/0x144)
    [    1.619934] [<c00088e8>] (do_one_initcall) from [<c04c0c54>] (kernel_init_freeable+0x13c/0x1dc)
    [    1.628620] [<c04c0c54>] (kernel_init_freeable) from [<c03737cc>] (kernel_init+0xc/0x118)

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>