Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932805Ab0DGPvq (ORCPT ); Wed, 7 Apr 2010 11:51:46 -0400 Received: from kroah.org ([198.145.64.141]:54208 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932649Ab0DGPvp (ORCPT ); Wed, 7 Apr 2010 11:51:45 -0400 Date: Wed, 7 Apr 2010 08:51:22 -0700 From: Greg KH To: Daniel Mack Cc: Alan Stern , linux-kernel@vger.kernel.org, Pedro Ribeiro , akpm@linux-foundation.org, Greg KH , alsa-devel@alsa-project.org, linux-usb@vger.kernel.org Subject: Re: USB transfer_buffer allocations on 64bit systems Message-ID: <20100407155122.GA13974@kroah.com> References: <20100407090623.GN30807@buzzloop.caiaq.de> <20100407151125.GJ30801@buzzloop.caiaq.de> <20100407153154.GC13425@kroah.com> <20100407153551.GK30801@buzzloop.caiaq.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100407153551.GK30801@buzzloop.caiaq.de> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1430 Lines: 33 On Wed, Apr 07, 2010 at 05:35:51PM +0200, Daniel Mack wrote: > On Wed, Apr 07, 2010 at 08:31:54AM -0700, Greg KH wrote: > > On Wed, Apr 07, 2010 at 05:11:25PM +0200, Daniel Mack wrote: > > > I vote for a clean solution, a fixup of existing implementations and > > > a clear note about how to allocate buffers for USB drivers. I believe > > > faulty allocations of this kind can explain quite a lot of problems on > > > x86_64 machines. > > > > Yeah, I really don't want to have to change every driver in different > > ways just depending on if someone thinks it is going to need to run on > > this wierd hardware. > > > > Alan, any objection to just using usb_buffer_alloc() for every driver? > > Or is that too much overhead? > > FWIW, most drivers I've seen in the past hours use a wild mix of > kmalloc(), kzalloc(), kcalloc() and usb_buffer_alloc(). That should > really be unified. Yes, if it is necessary that we have to handle this type of crappy hardware, then it all needs to be unified. Or at least unified into 2 types of calls, one that needs the bounce buffer fun (what usb_buffer_alloc() does today), and one that doesn't (usb_kzalloc() perhaps?) thanks, greg k-h -- 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/