8.0-RC1: AMD CS5536 (Geode) USB 2.0 controller strange behavour

Hans Petter Selasky hselasky at freebsd.org
Sun Sep 27 18:39:54 UTC 2009


On Sunday 27 September 2009 18:14:08 Eugene Grosbein wrote:
> On Sun, Sep 27, 2009 at 10:31:38PM +0800, Eugene Grosbein wrote:
> > > %dd if=/dev/zero bs=64k of=/dev/da0 count=1000
> > >
> > > It started to work, meantime iostat output was:
> > >
> > >  63.62  17  1.05
> > >   0.00   0  0.00
> > >   0.00   0  0.00
> > >   0.00   0  0.00
> > >   0.00   0  0.00
> > >   0.00   0  0.00
> > >  64.00   2  0.15
> > >  62.31  83  5.06
> > >   0.25   0  0.00
> > >   0.00   0  0.00
> > >   0.00   0  0.00
> > > ^C
>
> I've repeated the test with my USB flash drive formatted as FAT32.
> It gives the same result: for ICH7-based system I get 26 megabyte/s
> file writing speed and for AMD CS5536 it suffers from long periods of
> inactivity while writing data, hence very low awarage writing speed.
>
> It seems the root of the problem is in the interaction
> between USB stack and AMD CS5536 (Geode) USB 2.0 controller
> and not in media devices themselves.
>
> Any more hints please?

sysctl hw.usb.ehci.debug=15

If the USB stack puts the new job into the schedule and the USB controller 
does not pick it up, it is not an USB stack problem ...

--HPS



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