Re: Loading both the pata_atiixp and the ahci driver causes problems

[Jon Masters <jonathan@jonmasters.org>]

Tejun Heo wrote:
> Jon Masters wrote:
>> Chuck Ebbert wrote:
>>
>>> If you try to load both the pata_atiixp and the ahci driver
>>> (for the same ATI SB600 adapter), very strange things happen.
>>> The AHCI driver churns for three minutes or so, spewing
>>> messages like this, then nothing works:
>>>
>>> <6>ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
>>> <4>ata3.00: qc timeout (cmd 0xec)
>>> <4>ata3.00: failed to IDENTIFY (I/O error, err_mask=0x104)
>>> Shouldn't it be able to tell the device has already been
>>> claimed by some other driver?
>> One would assume it'd fail to grab the PCI IO ranges twice? I haven't
>> looked at the code but I have seen this bug mentioned elsewhere so I
>> might well end up having to do that yet :-)
> 
> Dunno much about sb600 but ahci and pata_atiixp are probably using
> separate IO regions && separate PCI functions.

Yeah. I actually thought about this whole issue a bit more recently - 
things like SATA/PATA interference when you've got a part that emulates 
legacy functionality so can appear as two different kinds of device - 
since I don't think my brain was really bothering to listen before. 
Words were going in, but it chose to ignore what was being said.

Only thing that comes to mind is in-driver logic/driver loading ordering 
hack combinations. At least if you've got loadable modules, you've got a 
fighting chance of fixing this kind of situation - built-in and you need 
to fight with whatever ordering exists in the array of init functions.

Jon.

P.S. Guess this means I need to admit I was wrong and apologize to 
Zaitcev sometime too in relation to another discussion...bah :P