Re: [PATCH v4 04/11] mips: use fallback for random_get_entropy() instead of zero

[Maciej W. Rozycki]

On Wed, 13 Apr 2022, Thomas Bogendoerfer wrote:

> > diff --git a/arch/mips/include/asm/timex.h b/arch/mips/include/asm/timex.h
> > index b05bb70a2e46..abc60a6395e3 100644
> > --- a/arch/mips/include/asm/timex.h
> > +++ b/arch/mips/include/asm/timex.h
> > @@ -94,7 +94,7 @@ static inline unsigned long random_get_entropy(void)
> >  	else if (likely(imp != PRID_IMP_R6000 && imp != PRID_IMP_R6000A))
> >  		return read_c0_random();
> >  	else
> > -		return 0;	/* no usable register */
> > +		return random_get_entropy_fallback();	/* no usable register */
> >  }
> >  #define random_get_entropy random_get_entropy
> >  
> > -- 
> > 2.35.1
> 
> Acked-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>

 Or we could drop the PRID_IMP_R6000/A check and the final `else' clause 
entirely, as we don't even pretend to support the R6k at all anymore, and 
this is the final reference remaining.  For one we no longer handle the 
CPU in `cpu_probe_legacy' so any attempt to boot on such a CPU would 
inevitably fail as no CPU options would be set (we probably should have a 
`panic' or suchlike as the default case for the switch statement there).

 Therefore I'm all for removing this piece instead, complementing commit 
3b2db173f012 ("MIPS: Remove unused R6000 support"), where it should have 
really happened.

  Maciej