From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEF87C433DB for ; Thu, 11 Feb 2021 14:11:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A715264E38 for ; Thu, 11 Feb 2021 14:11:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231701AbhBKOLi (ORCPT ); Thu, 11 Feb 2021 09:11:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:38616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232051AbhBKNw4 (ORCPT ); Thu, 11 Feb 2021 08:52:56 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 607B364E87; Thu, 11 Feb 2021 13:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613051534; bh=mx/ir5owcxGhvKP8aEP+Z9CweTjM4sRvImnbrqzIaKg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qII+HWhi8xgJ5IlTlO56BXxBwssvfap7hnge/KofbknZ8sD853Wf6dt42Kh5qcB+m 2fnvunOTGfX2pp/dTMOmkTGu2jqDCWmRgLOkmARhed8XpRn5PFpR6SlbOPocZXl/83 5tN0jKTpT7SpM1Yd+zEHYM4941nTSYiVB0BjjGK8= Date: Thu, 11 Feb 2021 14:52:12 +0100 From: "gregkh@linuxfoundation.org" To: David Laight Cc: 'Amey Narkhede' , "dan.carpenter@oracle.com" , "devel@driverdev.osuosl.org" , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" Subject: Re: [PATCH v4] staging: gdm724x: Fix DMA from stack Message-ID: References: <20210211053819.34858-1-ameynarkhede03@gmail.com> <500e7317567548b48604ed9972062da2@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <500e7317567548b48604ed9972062da2@AcuMS.aculab.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 11, 2021 at 01:28:41PM +0000, David Laight wrote: > > Stack allocated buffers cannot be used for DMA > > on all architectures so allocate hci_packet buffer > > using kmalloc. > > I wonder if the usb stack ought/could support a short bounce > buffer within the memory is already has to allocate? No.