Re: [powerpc:next 45/53] warning: (PPC_C2K && ..) selects NOT_COHERENT_CACHE which has unmet direct dependencies (4xx || ..)

[Fengguang Wu <fengguang.wu@intel.com>]

On Mon, Mar 10, 2014 at 10:49:24AM -0400, Paul Gortmaker wrote:
> On 14-03-08 03:07 AM, kbuild test robot wrote:
> > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc.git next
> > head:   c7e64b9ce04aa2e3fad7396d92b5cb92056d16ac
> > commit: 3c8464a9b12bf83807b6e2c896d7e7b633e1cae7 [45/53] powerpc: Delete old PrPMC 280/2800 support
> > config: make ARCH=powerpc c2k_defconfig
> > 
> > All warnings:
> > 
> > warning: (PPC_C2K && AMIGAONE) selects NOT_COHERENT_CACHE which has unmet direct dependencies (4xx || 8xx || E200 || PPC_MPC512x || GAMECUBE_COMMON)
> 
> This _looks_ like a new warning, but it really is not.  If you look
> at the tree prior to the above named commit, it generates this:
> 
> $ make c2k_defconfig
> warning: (PPC_PRPMC2800 && PPC_C2K && AMIGAONE) selects NOT_COHERENT_CACHE which has unmet direct dependencies (4xx || 8xx || E200 || PPC_MPC512x || GAMECUBE_COMMON)
> warning: (PPC_PRPMC2800 && PPC_C2K && AMIGAONE) selects NOT_COHERENT_CACHE which has unmet direct dependencies (4xx || 8xx || E200 || PPC_MPC512x || GAMECUBE_COMMON)
> #
> # configuration written to .config
> 
> So the warning is slightly different in text, but essentially
> the exact same thing that was being warned about before.  We've
> just removed one of the possible symbols from existence.

Yes, sorry, the kbuild robot is not smart enough to detect such
slightly changed error/warnings and will treat them as new ones.

> I'm not sure there would ever be a way to teach kbuild robot
> about something as subtle as the above; just one of the false
> positives that we'll have to live with, probably.

It is false positive: "this bug is not introduced by me!"

However if you take a broader view, it's still notifying the possibly
"relevant" people who may know the background about that bug, or whom
to further CC the report. :)

Thanks,
Fengguang