[PATCH v3] arm: remove unused code in delay.S
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Fri Sep 18 16:53:49 EDT 2009
On 15:25 Fri 18 Sep , Steve Chen wrote:
> On Fri, 2009-09-18 at 21:09 +0200, Uwe Kleine-König wrote:
> > Hello Steve,
> >
> > On Fri, Sep 18, 2009 at 11:46:58AM -0500, Steve Chen wrote:
> > > Document #if 0 code block in delay.S and make it selectable for compile.
> > >
> > > Signed-off-by: Steve Chen <schen at mvista.com>
> > >
> > > ---
> > > arch/arm/Kconfig | 31 +++++++++++++++++++++++++++++++
> > > arch/arm/lib/delay.S | 2 +-
> > > 2 files changed, 32 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > > index aef63c8..f44cb70 100644
> > > --- a/arch/arm/Kconfig
> > > +++ b/arch/arm/Kconfig
> > > @@ -813,6 +813,37 @@ config ARM_ERRATA_460075
> > > ACTLR register. Note that setting specific bits in the ACTLR
> > > register
> > > may not be available in non-secure mode.
> > >
> > > +config OLD_CPU_DELAY
> > > + depends on CPU_32v3 || CPU_32v4 || CPU_32v4T
> > > + bool "Different delay() code for some older CPUs"
> > > + def_bool n
> > as already noted, n is the default (that would better be expressed using
> > "default n" btw).
>
> Jean-Christope/Uwe, I'll change it to "default n".
simply remove it will be better
Best Regards,
J.
>
> >
> > > + help
> > > + Enable this if observing longer than expected delays. This code
> > > + improves delay accuracy for some CPUs. However, it can also cause
> > > + delay duration to be too short for others which leads to stability
> > > + issues.
> > > +
> > > + In other words, do not enable unless you can guarantee that the
> > > + processor (or ALL of the processors if building a generic kernel)
> > > + delays for at least the time requested after enabling.
> > > +
> > > + ARM610 and ARM710 are known to benefit from enabling this option.
> > > + It should not be enabled for StrongARMs, because it is known
> > > + to produce too short delays on those.
> > > +
> > > + Lastly, below are 2 lists. The first list contains the processors
simply remove it will be better
Best Regards,
J.> > > + that would benefit from enabling this flag, and the second list
> > > + contains processor that are known to have issues. Please note that
> > > + both lists are by no means complete. Entries are expected to be
> > > + added and refined. If you like to update the list, please send a
> > > + patch to Linux ARM mailing list.
> > I'd delete the last three sentences.
>
> Well, do. Anything after "Entries are expected to be..." will be
> deleted.
>
> >
> > > + CPUs should enable this flag
> > > + ARM610
> > > + ARM710
> > > +
> > > + CPUs should disable this flag
> > > + StrongARM
> > everything armv5+ ?
IIRC StrongARM is armv4
ARM610 & 710 is armv3
Best Regards,
J.
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