[PATCH v2] gianfar: Fall back to software tcp/udp checksum on oldercontrollers

[Scott Wood]

On Fri, 28 Jan 2011 09:10:46 +0000
David Laight <David.Laight at ACULAB.COM> wrote:

>  
> > +		if (unlikely(gfar_has_errata(priv, GFAR_ERRATA_12)
> > +			     && ((unsigned long)fcb % 0x20) > 0x18)) {
> 
> You need to check the generated code, but I think you need:
> 
>     if (unlikely(gfar_has_errata(priv, GFAR_ERRATA_12))
> 	     && unlikely(((unsigned long)fcb % 0x20) > 0x18))
> 
> ie unlikely() around both the primitive comparisons.

Is the first condition actually unlikely?  If you've got affected
hardware, you'll hit it every time.

If packets with the problematic alignment are rare, seems like it'd be
better to check that first.

-Scott