Re: [PATCH 1/3] Make the IDE DMA timeout modifiable

[Mark Lord]

Sergei Shtylyov wrote:
> Mark Lord wrote:
>
> > > O> >>    BTW, why the timeout is so damn long? 2*WAIT_CMD is 20 secs, 
> > > and if DMA is not complete or interrupt pending, it may wait 10 more secs...
..
> > I've lost the original question from this thread, but the idea of the 
>
>    The original question concerned specifically the DMA command timeout 
> which is twice more than the usual one, WAIT_CMD (10 seconds).
>
> > longish
> > timeouts was that drive *may* be spun down ("standby"), and thus have 
> > to spin
> > up again to complete media commands.  Back then, drives were much 
> > slower at
> > spinning up than nowadays, and the ATA spec says to allow up to 30 
> > seconds.
>
>    Well, that doesn't explain the DMA case.

When a drive is in standby, we don't send it anything special to wake up.
So even DMA commands have to have a long enough timeout to allow
for spinning up.

Cheers
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