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Date: Sun, 16 Apr 2006 07:33:45 +0200
From: Andre Draszik <kernel@andred.net>
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Subject: Re: IIC troubles w/ ppc4xx (STB04)
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Hi,

Eugene Surovegin wrote:
> On Sun, Apr 16, 2006 at 03:41:28AM +0200, Andre Draszik wrote:
>> [...]
>> Basically, I get a Data Machine Check as soon as iic->directcntl is
>> accessed. Actually, this register is not described in the (old)
>> documentation I have.
> 
> Does everything else work? I mean ordinary I2C access like read/write.

Well, i2c-dev is working fine, so i2c in general is working (w/
2.6.17-rc1). And also the initialization of the ibm i2c driver works
fine, i.e. all other registers can be accessed. It's only the directcntl
which throws the exception.

> If everything else is fine, just comment out that iic_smbus_quick() 
> call or just don't use i2c_probe(). It's a hack anyway, because I2C 
> spec has no provision for "probing". I wrote this bit-banging 
> implementation just to get some people off my back :).

I see :) So if that doesn't work, what is the preferred way of testing
for existence of a device in a kernel module? Should I just
unconditionally i2c_client_register() a static struct and then
i2c_master_send() to see if it works?

> BTW, I never tested my driver on STB4, maybe ocp_defs are wrong (in 
> this case i2c will not work at all).

Nope, this is correct, I already checked. :)


Thanks!
Andre'