Re: SATA_SIL on IXP425 workaround

[Jeff Garzik <jeff@garzik.org>]

On 01/14/2010 04:00 PM, Alan Cox wrote:
>> I think that you misinterpreted the issue -- according to Krzysztof MMIO
>> works just fine, only 8/16-bit MMIO reads are a problem (please note that
>> using mixed PIO/MMIO access is still a win over pure PIO access and also
>> that sata_sil doesn't support pure non-MMIO operations currently)..
>
> Have we got timing measurements to prove that ?
>>
>> However if it gets fixed in the upstream kernel in some other way I'll
>> simply drop the patch during the next re-base of my tree (I just collect
>> ATA stuff that looks useful/interesting to me and which otherwise may
>> become lost)..
>
> And that's a good thing. The question was aimed at Krzysztof. Really we
> need to keep platform specific weirdness out of core drivers or the
> rapidly turn into a mess.

The lack of 8-/16-byte MMIO access is unfortunately not limited to 
Krzysztof's platform.  Other people have reported the same problem 
specifically with sata_sil (see the archives).

If the driver cannot be converted to all-32-bit accesses, we will need 
to do something like Krzysztof's patch.

	Jeff