bce(4) un hiding adapter info

[Pyun YongHyeon]

On Thu, Sep 23, 2010 at 01:48:13PM -0700, David Christensen wrote:
> > > What I'd really like to do is revamp the debug code so that it
> > > can be enabled/disabled on the fly rather than requiring that
> > > the driver be compiled.  Adding some performance stuff would
> > 
> > Couldn't it be implemented with sysctl? Users may set a variable
> > something like dev.bce.0.diag_bitmap to activate debugging code.
> > But it seems that requires a lot of code changes.
> 
> I already have an extensive amount of conditionally compiled
> debug code in the driver which uses a bitmap to adjust the 
> debug spew.  For personal testing I've also added a sysctl
> to allow that value to be modified at runtime.  My concerns
> are from a security standpoint (some of the debug code allows
> direct register access), a code size perspective (adds a lot

Normal users couldn't change a sysctl variable so that information
is only available to root(Here I assume the feature is off by
default).

> of code most people don't use), and the performance penalty

I think code size wouldn't be large compared to firmware code. If
we switch to use firmware(9) I guess we can reduce the code size a
lot. We don't have to carry that image after downloading the
firmware.

> (lots of bitmap checking even when all debug spew is turned
> off).  
> 

That's correct. If that checking is not in fast path that
wouldn't affect much I guess.

> Probably worth the time to pull the most useful stuff into
> the production driver and leave the more obscure code in the
> debug only build.  If there are no complaints I'll add that
> to my task list.
> 
> Dave
>