From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756535Ab0DNRVK (ORCPT ); Wed, 14 Apr 2010 13:21:10 -0400 Received: from ey-out-2122.google.com ([74.125.78.26]:41576 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756495Ab0DNRVI convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2010 13:21:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=WBUyhEKScuPj143kpHyNCKLxKpHmx8XMMX3Q31fK9Yf8JNOaknxSPu8tmglM+2vy8r 9FvkTf5uD6UQ5inJLp4Ua2nmh92itltY0hLWIryAYNk8Ai8RraQdSt8lIXGLGLDICxWp RsxbX3qSNwX5/4yA43ODu27GUwnRgXjKtVYQo= MIME-Version: 1.0 In-Reply-To: <20100414163637.GV30807@buzzloop.caiaq.de> References: <20100414163637.GV30807@buzzloop.caiaq.de> Date: Wed, 14 Apr 2010 18:21:05 +0100 Message-ID: Subject: Re: USB transfer_buffer allocations on 64bit systems From: Pedro Ribeiro To: Daniel Mack Cc: Alan Stern , linux-usb@vger.kernel.org, Andi Kleen , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Greg KH , alsa-devel@alsa-project.org 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 On 14 April 2010 17:36, Daniel Mack wrote: > On Wed, Apr 14, 2010 at 10:08:47AM -0400, Alan Stern wrote: >> On Wed, 14 Apr 2010, Pedro Ribeiro wrote: >> > On 14 April 2010 11:09, Daniel Mack wrote: >> > > Thanks! So the only thing I can do for now is submit exactly this patch. >> > > At least, it helps you and it shouldn't break anything. The question >> > > remains whether this type of memory should be used for all >> > > transfer_buffers. >> > > >> > >> > Is there any chance you could push this to -stable? I don't care >> > because I always use the latest kernel, but the next Debian stable and >> > Ubuntu LTS are going to use 2.6.32. >> >> No!  Please don't do it: Don't submit the patch and _certainly_ don't >> submit it to -stable.  It doesn't fix anything; it only works around a >> bug, and at the moment we don't even know if the bug is in the kernel >> or in Pedro's hardware (and even though it affects two different >> systems of his, nobody else has reported a similar problem).  Papering >> over it will only remove the incentive to fix it properly. > > No worries - I agree. But unfortunately, I'm out of ideas now, and my > initial thoughts about what might cause the trouble were abviously not > able to explain the issue. Does anyone see further steps of tracking > this issue down? > > Thanks, > Daniel > Well if this is a dirty / dangerous hack, what about your first patch? I've been testing it for days and has given me no problems. 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. Regards, Pedro From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pedro Ribeiro Subject: Re: USB transfer_buffer allocations on 64bit systems Date: Wed, 14 Apr 2010 18:21:05 +0100 Message-ID: References: <20100414163637.GV30807@buzzloop.caiaq.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100414163637.GV30807-ahpEBR4enfnCULTFXS99ULNAH6kLmebB@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Daniel Mack Cc: Alan Stern , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andi Kleen , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, Greg KH , alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org List-Id: alsa-devel@alsa-project.org On 14 April 2010 17:36, Daniel Mack wrote: > On Wed, Apr 14, 2010 at 10:08:47AM -0400, Alan Stern wrote: >> On Wed, 14 Apr 2010, Pedro Ribeiro wrote: >> > On 14 April 2010 11:09, Daniel Mack wrote: >> > > Thanks! So the only thing I can do for now is submit exactly thi= s patch. >> > > At least, it helps you and it shouldn't break anything. The ques= tion >> > > remains whether this type of memory should be used for all >> > > transfer_buffers. >> > > >> > >> > Is there any chance you could push this to -stable? I don't care >> > because I always use the latest kernel, but the next Debian stable= and >> > Ubuntu LTS are going to use 2.6.32. >> >> No! =A0Please don't do it: Don't submit the patch and _certainly_ do= n't >> submit it to -stable. =A0It doesn't fix anything; it only works arou= nd a >> bug, and at the moment we don't even know if the bug is in the kerne= l >> or in Pedro's hardware (and even though it affects two different >> systems of his, nobody else has reported a similar problem). =A0Pape= ring >> over it will only remove the incentive to fix it properly. > > No worries - I agree. But unfortunately, I'm out of ideas now, and my > initial thoughts about what might cause the trouble were abviously no= t > able to explain the issue. Does anyone see further steps of tracking > this issue down? > > Thanks, > Daniel > Well if this is a dirty / dangerous hack, what about your first patch? I've been testing it for days and has given me no problems. 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. Regards, Pedro -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html