Re: PATA drivers in libata?

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Mon, 2005-02-14 at 20:42 +0000, Alan Cox wrote:
> On Llu, 2005-02-14 at 00:16, Jeff Garzik wrote:
> > Error handling is -very- stupid simple right now:  if we get an error, 
> > report that error in the struct request [based on your ATA -> SCSI sense 
> > conversion] back to upper layer.
> > 
> > It needs to be fleshed out into separate host bus / ATA bus / device 
> > errors, and handled accordingly.
> 
> Thats a barrier to real PATA IDE I guess then. We see a lot of cable
> errors and speed change downs and not all are caused by misdetecting
> 80wire cables.
> 
> The current IDE layer does speed changes synchronously outside the state
> machine which makes a nasty mess when your error handling interrupt
> state wants to speed change.

It's not _too_ bad ... you can just put the current request "on
hold" (and block the queue) until the thread finishes with the speed
change, but I tend to think nowadays that the state machine approach
might be better in the long run (even if a bit more complex to implement
in the first place).

Ben.