Re: [PATCH] ata: Add support for Long Logical Sectors and LongPhysical Sectors

From: Alan Cox
Date: Wed Aug 06 2008 - 10:30:50 EST


> Obviously it is going to change per command -- because different
> commands have different sizes. I was thinking that we could call the
> driver to see if it can handle a particular sector size right after we
> get the IDENTIFY data.

The drivers need to know if you are going to be using odd sizes regularly
so they can pick between

- I do this fine who cares (most chips)
- Er uh wtf its not 512 byts (some chip state machines)
- FIFO off (performance hit) for this disk
- FIFO managed for the odd command thats a funny size
- Various other levels of software managed controller
thumping

It's not a passive thing and we'd want to do it post identify on the
drive pair as it'll often need per channel decisions (eg on FIFO)

Alan
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