• Darren Salt's avatar
    eeepc-laptop: fix oops when changing backlight brightness during eeepc-laptop init · 7695fb04
    Darren Salt authored
    I got the following oops while changing the backlight brightness during
    startup.  When it happens, it prevents use of the hotkeys, Fn-Fx, and the
    lid button.
    
    It's a clear use-before-init, as I verified by testing with an
    appropriately-placed "else printk".
    
    BUG: unable to handle kernel NULL pointer dereference at 00000000
    *pde = 00000000
    Oops: 0002 [#1] PREEMPT SMP
    Pid: 160, comm: kacpi_notify Not tainted (2.6.28.1-eee901 #4) 901
    EIP: 0060:[<c0264e68>]  [<c0264e68>] eeepc_hotk_notify+26/da
    EFLAGS: 00010246 CPU: 1
    Using defaults from ksymoops -t elf32-i386 -a i386
    EAX: 00000009 EBX: 00000000 ECX: 00000009 EDX: f70dbf64
    ESI: 00000029 EDI: f7335188 EBP: c02112c9 ESP: f70dbf80
     DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
     f70731e0 f73acd50 c02164ac f7335180 f70aa040 c02112e6 f733518c c012b62f
     f70aa044 f70aa040 c012bdba f70aa04c 00000000 c012be6e 00000000 f70bdf80
     c012e198 f70dbfc4 f70dbfc4 f70aa040 c012bdba 00000000 c012e0c9 c012e091
    Call Trace:
     [<c02164ac>] ? acpi_ev_notify_dispatch+4c/55
     [<c02112e6>] ? acpi_os_execute_deferred+1d/25
     [<c012b62f>] ? run_workqueue+71/f1
     [<c012bdba>] ? worker_thread+0/bf
     [<c012be6e>] ? worker_thread+b4/bf
     [<c012e198>] ? autoremove_wake_function+0/2b
     [<c012bdba>] ? worker_thread+0/bf
     [<c012e0c9>] ? kthread+38/5f
     [<c012e091>] ? kthread+0/5f
     [<c0103abf>] ? kernel_thread_helper+7/10
    Code: 00 00 00 00 c3 83 3d 60 5c 50 c0 00 56 89 d6 53 0f 84 c4 00 00 00 8d 42
    e0 83 f8 0f 77 0f 8b 1d 68 5c 50 c0 89 d8 e8 a9 fa ff ff <89> 03 8b 1d 60 5c
    50 c0 89 f2 83 e2 7f 0f b7 4c 53 10 8d 41 01
    Signed-off-by: default avatarDarren Salt <linux@youmustbejoking.demon.co.uk>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    7695fb04
eeepc-laptop.c 20.9 KB