Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756673Ab0DNSxX (ORCPT ); Wed, 14 Apr 2010 14:53:23 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:33853 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756603Ab0DNSxV (ORCPT ); Wed, 14 Apr 2010 14:53:21 -0400 Date: Wed, 14 Apr 2010 14:53:20 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Pedro Ribeiro cc: Daniel Mack , David Woodhouse , USB list , Andi Kleen , Kernel development list , Andrew Morton , Greg KH Subject: Re: USB transfer_buffer allocations on 64bit systems In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 34 On Wed, 14 Apr 2010, Pedro Ribeiro wrote: > On 14 April 2010 19:23, Alan Stern 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/