Re: sata_sil and byte-aligned mmio

[Tejun Heo <htejun@gmail.com>]

Hello, Kevin.

Kevin Hilman wrote:
> Tejun,
> 
> A while back you provided a patch for sata_sil to use PCI IO space since
> so that it can work on hardware that doesn't support byte-aligned MMIO.
> 
> I'd like to see a fix for this pushed upstream, but IIRC, Jeff Garzik
> prefers that the driver be fixed up to use 32-bit aligned MMIO instead
> of making the driver use IO space.
> 
> If you can point me in the right direction, as to where the
> byte-alignement assumtions are, I can fix up the driver and test it on
> my hardware.

Byte-aligned IO accesses are in the default ATA operations - 
ata_tf_load/read, ata_check_status, ata_exec_command, 
ata_std_dev_select, all the bmdma ops, etc...  Basically, traditional 
ATA interface is designed to use byte-aligned registers to operate.

sil3112 family of controllers allow all those ops implemented using 
32bit ops, so you need to implement sata_sil's own methods to replace 
those standard byte-aligned ops.  I don't think it's gonna be too difficult.

Good luck. :-)

-- 
tejun