From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [LKML] Re: USB transfer_buffer allocations on 64bit systems Date: Fri, 9 Apr 2010 16:25:33 -0400 Message-ID: <20100409202533.GA8983@phenom.dumpdata.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alan Stern Cc: Pedro Ribeiro , Daniel Mack , Robert Hancock , 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, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: alsa-devel@alsa-project.org On Fri, Apr 09, 2010 at 03:34:06PM -0400, Alan Stern wrote: > On Fri, 9 Apr 2010, Pedro Ribeiro wrote: > > > > The DMA pointers do indeed look sane. I wanted to take a deeper look at > > > this and set up a 64bit system today. However, I fail to see the problem > > > here. Pedro, how much RAM does your machine have installed? > > > It has 4 GB. > > That means DMA mapping cannot be the cause of the problem. :-( That isn't entirely true. The BIOS usually allocates a 256 MB ACPI/PCI hole that is under the 4GB. So end up with 3.7 GB, then the 256MB hole, and then right above the 4GB you the the remaining memory: 4.3GB. -- 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