Re: sg regression in 2.6.16-rc5

[Jeff Garzik]

Linus Torvalds wrote:
> On Fri, 3 Mar 2006, Jeff Garzik wrote:
>
> > 256 max sectors IDE driver, 200 max sectors libata (due to driver not
> > hardware).
>
>
> When I said "lower due to broken hw" I was more thinking about things like 
> the SiIimage driver, which actually limits the rqsize to 15 sectors due to 
> some strange hw interactions with seagate SATA devices.

Yep.  There's trouble if the last FIS (sata packet, max 8K) is exactly 7.5K.


> (It will then raise it back up to 128 if it's not a Seagate SATA drive. I 
> forget what the exact issue was. Some strange corruption in some limited 
> case, and not allowing big requests worked around it. There's some 
> strange IDE quirks out there...).

Technically its

	if (sectors % 15 == 1)
		explode

:)  Yes, IDE is a weird weird world...

	Jeff


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