Re: [PATCH] Poll-based IDE driver

[Jamie Lokier]

Alan Cox wrote:
> On Mer, 2003-10-08 at 13:14, Srivatsa Vaddagiri wrote:
> > Since my code is supposed to run when system is crashing, I would like 
> > to avoid calling any function in the kernel as far as possible, since 
> > the kernel and its data structures may be in a inconsistent state 
> > and/or corrupted.
> 
> For x86 udelay is a tiny piece of code - you could easily inline it

No, because that changes the delay.  Things like whether the
instructions straddle a cache line or page boundary, or ar 4-byte or
16-byte aligned affect the timing on some x86 CPUs.

udelay must reside at a fixed memory location to get the nearest thing
to determinism that we know how to get.

-- Jamie
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