Re: Early ATA devices

[Jeff Garzik <jeff@garzik.org>]

Alan Cox wrote:
> #1	We assume identify works. Early ATA actually lists this command
> as optional

ITYM we assume identify command exists on the device?

We certainly do not assume IDENTIFY command, if exists, succeeds.

What is the proper probing method -- notice if command-aborted is 
returned and do something from there?


> #2	We don't allow for INIT_DEV_PARAMS failing which it may do on
> some early IDE pre ATA devices

Suggested handling?  Ignore device, since we don't know what state its 
in, if this fails?


> We check ATA < 4 || non-LBA capable when deciding whether to issue
> INIT_DEV_PARAMS. ATA 4+ however mandate LBA so the second case isn't
> theoretically at least possible.

I agree, though I figured that the current code was more robust, in case 
some weirdo device decided to forget its LBA-ness.

No strong opinions here, though.


> So in theory we can persuade libata to drive original MFM/RLL disks with
> relatively few changes

Crazy :)

	Jeff