Re: PATCH[[vme/bridges/vme_ca91cx42.c:1382: Bad if test Bug Fix]ââ

[Martyn Welch]

On 16/06/14 10:56, Dan Carpenter wrote:
> On Mon, Jun 16, 2014 at 10:47:25AM +0100, Martyn Welch wrote:
> > Nick,
> >
> > Sorry for the delay in responding.
> >
> > I'm staring at the manual for the ca91c142 and the relevant bits in
> > the VSIx_CTL registers definitely need to be set to 0 for A16,
> > likewise with the LM_CTL register. The pattern (3<<16) would enable
> > one of the "reserved" address spaces.
>
> Nick emailed me privately that this was a static checker warning.  These
> warnings are often false positives...  But I'm worried about the test:
>
> 	if ((ctl & CA91CX42_VSI_CTL_VAS_M) == CA91CX42_VSI_CTL_VAS_A16)
> 		*aspace = VME_A16;
>
> That could be true when we didn't intend it.

If I'm not mistaken, CA91CX42_VSI_CTL_VAS_A16 is currently defined as 0.

So:
	if ((ctl & (7<<16) == 0)
		*aspace = VME_A16;

Which looks right to me, it's checking to see if the relevant bits in 
the register are all zero, am I missing something obvious?

Martyn


--
Martyn Welch (Lead Software Engineer)  | Registered in England and Wales
GE Intelligent Platforms               | (3828642) at 100 Barbirolli Square
T +44(0)1327322748                     | Manchester, M2 3AB
E martyn.welch@xxxxxx                  | VAT:GB 927559189
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/