Re: Problem with random.c and PPC

From: Oliver Xymoron (
Date: Fri Aug 16 2002 - 11:28:02 EST

On Thu, Aug 15, 2002 at 02:04:49PM -0700, Tom Rini wrote:
> On Thu, Aug 15, 2002 at 01:59:33PM -0600, Andreas Dilger wrote:
> > On Aug 15, 2002 12:03 -0700, Tom Rini wrote:
> > > On Thu, Aug 15, 2002 at 12:25:56PM -0600, Andreas Dilger wrote:
> > > > Maybe the PPC keyboard/mouse drivers do not add randomness?
> > >
> > > Well, how is this set for the i386 ones? I grepped around and I didn't
> > > really see anything, so I'm sort-of confused.
> >
> > I think it is something like "add_mouse_entropy" and "add_keyboard_entropy"
> > or similar. If you look at the random.c sources you can find the actual
> > function names and work backwards from there.
> Ah, thanks. In that case, no. It doesn't look like the input-layer USB
> keyboards contribute to entropy (but mice do), and I don't think the ADB
> ones do. I'll take a crack at adding this to keyboards monday maybe.

Tom, I'm working on a set of patches that completely change this
interface because there are a bunch of problems with the current
entropy accounting.

What PPC and other arches really need in this area is a higher
resolution timing source. The jiffies-based timing is rather
limiting, especially after the entropy accounting stops overestimating
things by orders of magnitude. Does the PPC port have a convenient way
to access the TBR or something similar?

 "Love the dolphins," she advised him. "Write by W.A.S.T.E.." 
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