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SubjectRe: [PATCH 1/3] hvc_dcc: Fix bad code generation by marking assembly volatile
Hi!

> > diff --git a/drivers/char/hvc_dcc.c b/drivers/char/hvc_dcc.c
> > index 6470f63..155ec10 100644
> > --- a/drivers/char/hvc_dcc.c
> > +++ b/drivers/char/hvc_dcc.c
> > @@ -33,8 +33,7 @@
> > static inline u32 __dcc_getstatus(void)
> > {
> > u32 __ret;
> > -
> > - asm("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
> > + asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
> > : "=r" (__ret) : : "cc");
> >
> > return __ret;

Is volatile needed here? If __dcc_getstatus() return value is
discarded, we want assembly discarded, right?


> > @@ -58,7 +57,7 @@ static inline char __dcc_getchar(void)
> > {
> > char __c;
> >
> > - asm("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
> > + asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
> > : "=r" (__c));
> >
> > return __c;

Same here?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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