Re: [PATCH] Re: Linux v2.6.22-rc3

[Alan Cox]

On Fri, 8 Jun 2007 11:35:13 -0400
Jeff Garzik <jeff@xxxxxxxxxx> wrote:

> On Fri, Jun 08, 2007 at 04:38:04PM +0100, Alan Cox wrote:
> > > See a URL I posted earlier in this thread.  With dumb ATAPI devices we
> > > actually have to wait a bit for BSY to be asserted.  Not only at reset,
> > > but also for every command
> > 
> > 400nS and the current code correctly accounts for it.
> 
> No, _far_ longer than 400nS.  2ms minimum by the spec, but,
> 
> ATADRVR. blackmagic.html and googling around shows plenty of ATAPI
> devices that don't get their shit together for 50-100ms.

400nS is commands. Reset is indeed about 150mS or so if you catch a drive
right - eg in the middle of revalidating a dodgy disk. One or two have
really weird behaviour in that they take MUCH longer to come out of reset
with no media loaded.
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