4.10-rc3 rpi issues

[Gerd Hoffmann]

  Hi,

> > usb is flaky.  raspberry pi 2 b.  Has a edimax wifi dongle, and that
> > stopped working.  rtl8xxxu driver.  Doesn't find any wifi networks.  usb
> > keyboard has problems too, looses keys now and then, which makes me
> > think this is more a usb than a wifi problem.  I had that before, with
> > the 4.8 kernels.  4.9 works fine.  Now with 4.10-rc3 the problems are
> > back :(  Anyone seen this too?  Any clues what this might be?

> The Fedora built rc3 kernel seems OK. I'm using usb wifi ATM without
> too many issues and haven't had any drop outs. I've seen some
> interesting bits with CMA which I reported [1]. USB doesn't appear at
> least in my testing to be any worse on the 2 or 3.

Tried to enable some memory debugging, so see if that helps to figure
what is going on:

    CONFIG_DEBUG_KMEMLEAK=y
    CONFIG_DEBUG_MEMORY_INIT=y
    CONFIG_SLUB_DEBUG=y
    CONFIG_SLUB_DEBUG_ON=y

That made the bug disappear.  :-o

Rawhide kernels are build with quite some debug turned on too, right?
So that could be it.  Or it is something else:  timing, memory layout /
alignment, ...

cheers,
  Gerd