[PATCH] arm: spin one more cycle in timer-based delays

[Russell King - ARM Linux]

On Sun, Nov 20, 2016 at 11:18:48AM -0800, Doug Anderson wrote:
> Hi,
> 
> On Sat, Nov 19, 2016 at 10:29 AM, Mason <slash.tmp at free.fr> wrote:
> >> Exactly - and the reason for that (as I've explained several times in
> >> the past) the "standard" software delay loop calibrated against the
> >> timer interrupt is _always_ going to be short.
> >
> > OK, so loop-based delays are known to be short. Would you or Linus
> > accept a patch that adds a X% cushion *in the implementation* ?
> >
> > You are saying "people shouldn't expect udelay(10) to delay at least
> > 10 µs, thus they should write udelay(10+N)".
> >
> > Why not hide that implementation detail inside the implementation,
> > so as not to force the pessimization on every other implementation
> > behind the udelay/ndelay wrapper?

Try sending Linus a patch for it.

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