Subject: Re: crash on CONFIG_CFAG12864B=y in 2.6.20-rc3-mm1
From: Daniel Walker <dwalker@mvista.com>
To: Miguel Ojeda <maxextreme@gmail.com>
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org
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Date: Thu, 01 Feb 2007 07:16:31 -0800
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On Thu, 2007-02-01 at 16:16 +0100, Miguel Ojeda wrote:
> The problem is easy:
> 
> ks0108_init() prints the error message and exit with -EINVAL, so the
> module isn't loaded properly.
> 
> However, cfag12864b_init() is called, although ks0108 failed. It
> returns 0 and after a while cfag12864b calls ks0108_writecontrol()
> which dereferences the uninitialized pointer ks0108_parport:
> 
> 	parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
> 
> Why is cfag12864b_init() called if ks0108 module didn't load properly?
> Is that normal? If so, how a module should alarm other modules about
> it failed loading?

I don't know if this matters, but I had this driver built-in , and not a
module ..

Daniel

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