Re: [PATCH 1/3] hvc_dcc: Fix bad code generation by markingassembly volatile

[Pavel Machek]

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
-- 
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