[PATCH] ARM: avoid undef on ARCH_HAS_READ_CURRENT_TIMER

[Russell King - ARM Linux]

On Tue, Sep 11, 2012 at 12:19:00PM -0400, Cyril Chemparathy wrote:
> With the inclusion of asm-generic/timex.h, the ARM arch timer implementation
> breaks on build.  This is because asm/arch_timer.h now defines
> ARCH_HAS_READ_CURRENT_TIMER, only to have this macro undefined by the
> subsequent inclusion of asm-generic/timex.h.
> 
> This patch fixes the problem in asm/timex.h by including asm-generic/timex.h
> early, and by defining get_cycles even earlier.
> 
> This patch has been tested against linux-next-20120910, both with and without
> arch timer support.

Given the complexity this introduces, just for the sake of using one
thing from asm-generic/timex.h:

typedef unsigned long cycles_t;

it seems utterly pointless to use the asm-generic version at all,
especially if we have to play games to work around what it's doing.
What this means is one of two things.  Either we should not be using
asm-generic/timex.h, or asm-generic/timex.h as currently exists is
broken.