Re: USB transfer_buffer allocations on 64bit systems

[Alan Stern]

On Wed, 14 Apr 2010, Pedro Ribeiro wrote:

> On 14 April 2010 19:23, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Wed, 14 Apr 2010, Pedro Ribeiro wrote:
> >
> >> The best way to trigger the issue is to connect a dib0700 based DVB
> >> adapter. All you need is to connect it. Since it polls for the remote
> >> control every 50 msec, it causes a constant interference. Beware that
> >> on 2.6.34 this behaviour has been corrected. Other DVB adapters may
> >> trigger the same issue if they also poll constatly for the rc.
> >
> > Your computer has two EHCI controllers, doesn't it?  Can you plug the
> > DVB into a different USB bus from the audio device?  If you do, does
> > the interference still occur?
> >
> > Alan Stern
> >
> >
> 
> It does not matter on which ports I plug into, even if in different
> buses not sharing IRQ's.

Okay, good.  That's important.  If the problem went away when the two
devices were on separate buses then it would have to be a bug in
ehci-hcd.  But since it didn't go away, it must be a bug in the
memory/buffering code or in the hardware.

Alan Stern

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