Missing config option for SFFSDR_FPGA

Missing config option for SFFSDR_FPGA

[Christian Dietrich]

Hi all!
       
        As part of the VAMOS[0] research project at the University of
Erlangen we are looking at multiple integrity errors in linux'
configuration system.

        I've been running a check on the sound/ sourcetree for
config Items not defined in Kconfig and found such a case. Sourcecode
blocks depending on these Items are not reachable from a vanilla
kernel -- dead code. I've seen such dead blocks made on purpose
e.g. while integrating new features into the kernel but generally
they're just useless.

There are two ifdef blocks, which do a check on CONFIG_SFFSDR_FPGA, but
this flag isn't defined anywhere. There is an select in
sound/soc/davinci[1], but Kconfig doesn't define the symbol, if there
isn't a config option for it. So this blocks can never be selected. I
don't think this is intended, so i didn't wrote a patch. Please just
notice it.

Regards
        Christian Dietrich

[0] http://vamos1.informatik.uni-erlangen.de/
[1] sound/soc/davinci/Kconfig:      select SFFSDR_FPGA                 
    sound/soc/davinci/davinci-sffsdr.c:#ifdef CONFIG_SFFSDR_FPGA
    sound/soc/davinci/davinci-sffsdr.c:#ifndef CONFIG_SFFSDR_FPGA
    sound/soc/davinci/davinci-sffsdr.c:#ifndef CONFIG_SFFSDR_FPGA
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Re: Missing config option for SFFSDR_FPGA

[Mark Brown]

On Wed, Jul 21, 2010 at 12:58:33PM +0200, Christian Dietrich wrote:

>         As part of the VAMOS[0] research project at the University of
> Erlangen we are looking at multiple integrity errors in linux'
> configuration system.

As I keep saying every time someone reports this problem you really need
to speak to the people responsible for the platform.  This is an issue
specific to the relevant board, please contact the maintainers of the
specific system.

If you're going to do this sort of work you need to watch out for
embedded devices - you will need to make sure to contact the people
responsible for the device as well as the subsystem maintainers who
will often have no specific knowledge of the individual systems.

Re: Missing config option for SFFSDR_FPGA

[Takashi Iwai]

At Wed, 21 Jul 2010 13:28:53 +0100,
Mark Brown wrote:
> 
> On Wed, Jul 21, 2010 at 12:58:33PM +0200, Christian Dietrich wrote:
> 
> >         As part of the VAMOS[0] research project at the University of
> > Erlangen we are looking at multiple integrity errors in linux'
> > configuration system.
> 
> As I keep saying every time someone reports this problem you really need
> to speak to the people responsible for the platform.  This is an issue
> specific to the relevant board, please contact the maintainers of the
> specific system.
> 
> If you're going to do this sort of work you need to watch out for
> embedded devices - you will need to make sure to contact the people
> responsible for the device as well as the subsystem maintainers who
> will often have no specific knowledge of the individual systems.

The problem is that the drivers for embedded platforms are often out
of sync.  davinci is one of such platforms.  So, as Mark suggested,
it'd be better to talk with guys responsible for such a system
beforehand.

Of course, as upstream, we can clean up things here.  But, I'd like to
see this clean-up rather from the platform side.  In that way, it can
be synchronized better.


thanks,

Takashi

Re: Missing config option for SFFSDR_FPGA

[Mark Brown]

On Wed, Jul 21, 2010 at 02:34:25PM +0200, Takashi Iwai wrote:

> The problem is that the drivers for embedded platforms are often out
> of sync.  davinci is one of such platforms.  So, as Mark suggested,
> it'd be better to talk with guys responsible for such a system
> beforehand.

> Of course, as upstream, we can clean up things here.  But, I'd like to
> see this clean-up rather from the platform side.  In that way, it can
> be synchronized better.

More generally nobody who doesn't have the board is going to care about
things in a board-specific file too much, and with a lot of boards
there's substantial code carried out of tree that's not yet made it into
mainline for one reason or another.