Re: [PATCH] speed up SATA

From: Stefan Smietanowski
Date: Sun Mar 28 2004 - 02:26:39 EST

Hi Jeff.

What will happen when a PATA disk lies behind a Marvel(ous) bridge, as
in most SATA disks today?

Larger transfers work fine in PATA, too.

Correct me if I'm wrong but wasn't the max number of sectors in a
transfer limited to 255 instead of 256 because there were buggy
drives out there before ? I seem to recall something like that but
I could be wrong.

Of course I hope nobody in his right mind would take those old things,
slap a Marvel chip on it and sell it as new :) But someone else could
buy one of those SATA<->PATA converter cables with a Marvel on it and
run it with the old disk <shudder>. Wouldn't those cases bug out?

Is large transfers mandatory in the LBA48 spec and is LBA48 really
mandatory in SATA?

Yes and no, in that order :) SATA doesn't mandate lba48, but it is highly unlikely that you will see SATA disk without lba48.

Naturally, see my comment above regarding SATA<->PATA converter cables.

Regardless, libata supports what the drive supports. Older disks still work just fine.

Or.. should :)

// Stefan
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