Re: ATA device reset, shoud I be concerned?

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

> I still don't think it's worth the trouble.  There's currently only one
> reported device which forgets to raise IRQ on media error.  The behavior

Most people wouldn't realise what is going on.

> > Old IDE says it works for PATA. For SATA I can see it might need more
> > care and you might simply not be able to get the info.
> 
> Old IDE often locks up the machine hard after timeouts.  I'm all for

The code paths are racy - it didn't use to in 2.4 (except for the promise
drain bug)

> gathering more info but benefit vs. risk equation just doesn't look good
> here.  Why take risk for a rare device which forgets to raise IRQ on
> media error?  If such behavior is wide spread among PATA drives && we
> can verify that TF register access after timeout is safe for PATA
> controllers, sure, but currently we aren't sure about either.

We lose IRQs in lots of other cases. Promise PATA is particularly bad at
forgetting to give us the completion interrupt.

Alan