Re: crash on CONFIG_CFAG12864B=y in 2.6.20-rc3-mm1

["Miguel Ojeda" <maxextreme@gmail.com>]

On 1/7/07, Daniel Walker <dwalker@mvista.com> wrote:
> (forgot to CC LKML)
>
> The options,
>
> CONFIG_CFAG12864B=y
> CONFIG_CFAG12864B_RATE=20
>
> causes a crash at boot in 2.6.20-rc3-mm1. I don't have the hardware
> associated with the options. It looks like it just doesn't have guards
> to detect if the hardware doesn't exists.
>
> Here is the crash,
>
> ks0108: ERROR: parport didn't find 888 port
> BUG: unable to handle kernel NULL pointer dereference at virtual address
> 0000004 printing eip:
> c02dbff9
> *pde = 00000000
> Oops: 0000 [#1]
> PREEMPT SMP
> last sysfs file:
> Modules linked in:
> CPU:    3
> EIP:    0060:[<c02dbff9>]    Not tainted VLI
> EFLAGS: 00010246   (2.6.20-rc3-mm1 #11)
> EIP is at ks0108_writecontrol+0x79/0xc0
> eax: 00001008   ebx: 0000000a   ecx: 673e2eb8   edx: 00000001
> esi: 0000000a   edi: 00000000   ebp: f7c3ff6c   esp: f7c3ff50
> ds: 007b   es: 007b   fs: 00d8  gs: 0000  ss: 0068
> Process swapper (pid: 1, ti=f7c3e000 task=f7c26a90 task.ti=f7c3e000)
> Stack: 00000001 f7552c40 f7c3ff60 c0120e3f 00000000 c049f450 00000000
> f7c3ff74
>        c02dc159 f7c3ff80 c02dc177 00000000 f7c3ff98 c048feda 00000378
> c02d74db
>        00000000 00000000 f7c3ffe0 c0478610 c03d9d35 00000004 f7c26a90
> c0473fc4
> Call Trace:
>  [<c01053da>] show_trace_log_lvl+0x1a/0x30
>  [<c0105499>] show_stack_log_lvl+0xa9/0xd0
>  [<c01056c7>] show_registers+0x207/0x370
>  [<c0105949>] die+0x119/0x250
>  [<c011d267>] do_page_fault+0x277/0x610
>  [<c038e9d4>] error_code+0x7c/0x84
>  [<c02dc159>] cfag12864b_e+0x19/0x20
>  [<c02dc177>] cfag12864b_page+0x17/0x30
>  [<c048feda>] cfag12864b_init+0x8a/0x130
>  [<c0478610>] init+0x110/0x250
>  [<c0104fd3>] kernel_thread_helper+0x7/0x14
>  =======================
> Code: 8b 98 ec 00 00 00 0f b6 03 24 df 88 45 f3 80 75 f3 20 0f b6 43 01 20
> 45 f
> EIP: [<c02dbff9>] ks0108_writecontrol+0x79/0xc0 SS:ESP 0068:f7c3ff50
>  <0>Kernel panic - not syncing: Attempted to kill init!
>
>
>
>

As Daniel Walker pointed out, the driver doesn't probe for the
hardware because it just uses the parallel port for output (there
isn't any kind of input).

The driver shouldn't continue execution and using
ks0108_writecontrol() (which writes to the parallel port) after the
"ks0108: ERROR: parport didn't find 888 port" message.

Will check.

Thanks for the warning,
Miguel

(forgot to reply to all).

-- 
Miguel Ojeda
http://maxextreme.googlepages.com/index.htm