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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 BC816C4727E for ; Tue, 22 Sep 2020 11:49:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 869122388B for ; Tue, 22 Sep 2020 11:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726950AbgIVLtM (ORCPT ); Tue, 22 Sep 2020 07:49:12 -0400 Received: from elvis.franken.de ([193.175.24.41]:51255 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726573AbgIVLsw (ORCPT ); Tue, 22 Sep 2020 07:48:52 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1kKfxr-000822-01; Tue, 22 Sep 2020 12:56:03 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id B061AC0FFF; Tue, 22 Sep 2020 10:49:34 +0200 (CEST) Date: Tue, 22 Sep 2020 10:49:34 +0200 From: Thomas Bogendoerfer To: Christoph Hellwig Cc: Mauro Carvalho Chehab , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Ben Skeggs , Marek Szyprowski , Tomasz Figa , Matt Porter , iommu@lists.linux-foundation.org, Stefan Richter , linux1394-devel@lists.sourceforge.net, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, netdev@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mm@kvack.org, alsa-devel@alsa-project.org Subject: Re: [PATCH 07/18] 53c700: improve non-coherent DMA handling Message-ID: <20200922084934.GB8477@alpha.franken.de> References: <20200915155122.1768241-1-hch@lst.de> <20200915155122.1768241-8-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200915155122.1768241-8-hch@lst.de> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On Tue, Sep 15, 2020 at 05:51:11PM +0200, Christoph Hellwig wrote: > Switch the 53c700 driver to only use non-coherent descriptor memory if it > really has to because dma_alloc_coherent fails. This doesn't matter for > any of the platforms it runs on currently, but that will change soon. > > To help with this two new helpers to transfer ownership to and from the > device are added that abstract the syncing of the non-coherent memory. > The two current bidirectional cases are mapped to transfers to the > device, as that appears to what they are used for. Note that for parisc, > which is the only architecture this driver needs to use non-coherent > memory on, the direction argument of dma_cache_sync is ignored, so this > will not change behavior in any way. > > Signed-off-by: Christoph Hellwig > --- > drivers/scsi/53c700.c | 113 +++++++++++++++++++++++------------------- > drivers/scsi/53c700.h | 17 ++++--- > 2 files changed, 72 insertions(+), 58 deletions(-) Tested-by: Thomas Bogendoerfer -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]