Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755364AbYF3OEI (ORCPT ); Mon, 30 Jun 2008 10:04:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751440AbYF3ODz (ORCPT ); Mon, 30 Jun 2008 10:03:55 -0400 Received: from rv-out-0506.google.com ([209.85.198.237]:47058 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751189AbYF3ODy (ORCPT ); Mon, 30 Jun 2008 10:03:54 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Wf5t6C28Of0kk2kngEF9IcFdh9tBB3OwMzrZYVJFSVuY9903UbAXOTTo7TdDQiBGn4 jV6bLyhqiEhyef4Vyrr8nvnx1H9ewfVGrIejagjsIgE4dzJv/ydnk+rfRfRWeXUGnqxQ sBQkaISYZ38acKn1eXW7qT9GfNg5tEVf524c0= Message-ID: <38b2ab8a0806300703j7c0f0567w4cf1730fbe375c00@mail.gmail.com> Date: Mon, 30 Jun 2008 16:03:52 +0200 From: "Francis Moreau" To: "Oliver Neukum" Subject: Re: usb_get_status(): what a weird implementation ! Cc: "David Brownell" , linux-usb@vger.kernel.org, "Linux Kernel Mailing List" In-Reply-To: <200806301551.42252.oliver@neukum.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200806261011.00287.oliver@neukum.org> <200806301346.11267.oliver@neukum.org> <38b2ab8a0806300541q756e9b6fl445a5ee69d403ce7@mail.gmail.com> <200806301551.42252.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 774 Lines: 23 On Mon, Jun 30, 2008 at 3:51 PM, Oliver Neukum wrote: > > If your buffer is smaller than CACHE_LINE_SIZE it should work. > However, this needs input from people who understand DMA in and out. yeah, that's the reason why it's a hack. Maybe adding a new helper in the dma API would be better... > But how large is 2 * CACHE_LINE_SIZE compared to the kernel stack? CACHE_LINE_SIZE = 32 bytes is common for embedded systems I guess. For big system, I dunno. Kernel stack size is usually 4KiB. -- Francis -- 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/