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=-7.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 0F511ECDFB6 for ; Tue, 1 Oct 2019 06:37:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6D032133F for ; Tue, 1 Oct 2019 06:37:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PBu8Coen" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732441AbfJAGhq (ORCPT ); Tue, 1 Oct 2019 02:37:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:39110 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbfJAGhq (ORCPT ); Tue, 1 Oct 2019 02:37:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1J2bXPCX7WE0H0txEjX0ivUz5quBP90hFeMgyCZKxxo=; b=PBu8CoencaxSyAddpHhtk33O1 pscNJjIe2M6BHbx5hsP0da5LBziJK9lGdykY1AKQZ+I9oApgaowj8CS7DQHxN2F956cRGedrXzu3k Lvv58vkz9vBT6yrNgCDdK+dPResg6761Wm4yLVdYa8I+PpqzTWZ8lVe+RN1as6JstbuhDMKycS6LL 0OhKiwCi8iCZNM+ifUqrk5ymys1Wo/BipAbs7jyIKFu+giaW9bXDJDZt2bO7a37D2aIHRyHUolSy2 yVCwZv/mDjrn6oRHhbvCTu1B4oY33aIUdmOBmY2XU/HkNLfUk9rJ9e1tAnd03WE8wCfraM4ssvOCX 0+rFJHt9w==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFBn6-00035m-Fo; Tue, 01 Oct 2019 06:37:44 +0000 Date: Mon, 30 Sep 2019 23:37:44 -0700 From: Christoph Hellwig To: Nicolas Boichat Cc: Shik Chen , Linux Media Mailing List , Tomasz Figa , notify@kernel.org, Keiichi Watanabe , Ricky Liang , Mauro Carvalho Chehab , Laurent Pinchart , lkml , kieran.bingham@ideasonboard.com, Vlastimil Babka , Christoph Lameter , Christoph Hellwig Subject: Re: [PATCH] media: uvcvideo: Use streaming DMA APIs to transfer buffers Message-ID: <20191001063744.GA10402@infradead.org> References: <20190802131226.123800-1-shik@chromium.org> <20190930082310.GA1750@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190930082310.GA1750@infradead.org> User-Agent: Mutt/1.12.1 (2019-06-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 30, 2019 at 01:23:10AM -0700, Christoph Hellwig wrote: > And drivers really have no business looking at the dma mask. I have > a plan for dma_alloc_pages API that could replace that cruft, but > until then please use GFP_KERNEL and let the dma subsystem bounce > buffer if needed. Can you try this series: http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma_alloc_pages and see if it does whay you need for usb?