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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 98111C433FF for ; Fri, 2 Aug 2019 21:38:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 679DA206A3 for ; Fri, 2 Aug 2019 21:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395051AbfHBViB (ORCPT ); Fri, 2 Aug 2019 17:38:01 -0400 Received: from verein.lst.de ([213.95.11.211]:56230 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726059AbfHBViA (ORCPT ); Fri, 2 Aug 2019 17:38:00 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id BE1CD68AFE; Fri, 2 Aug 2019 23:37:56 +0200 (CEST) Date: Fri, 2 Aug 2019 23:37:56 +0200 From: Christoph Hellwig To: Rob Clark Cc: Stephan Gerhold , Rob Clark , Sean Paul , linux-kernel@vger.kernel.org, torvalds@linux-foundation.org Subject: please revert "drm/msm: Use the correct dma_sync calls in msm_gem" Message-ID: <20190802213756.GA20033@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, I just saw your above commit in Linus' tree, which is completely bogus and misunderstand the DMA API. Next time you have any issues please Cc the relevant maintainers and mailing lists. But even more importantly get_dma_ops is an completely internal API, and whatevet your helpers are trying to do is bad - if the dma wasn't mapped at the time you call the new sync_for_device helper, this is broken because you can't call dma_sync_sg_for_device on unmapped address. If it was mapped it is bogus as well as you can't double map it. Please describe what you're actually trying to fix and we're going to work on a proper solution, but this shot from the hip is just going to make things worse.