Received: by 2002:ac0:a5a7:0:0:0:0:0 with SMTP id m36-v6csp3745274imm; Tue, 17 Jul 2018 09:34:45 -0700 (PDT) X-Google-Smtp-Source: AAOMgpedPQEIGPLjC54BddxEmmU2PI6ZtafDP2wHrz8u17RmqkusI6FrVuS7LuX1XqW17ABHcbRZ X-Received: by 2002:a63:9e0a:: with SMTP id s10-v6mr2271834pgd.326.1531845285604; Tue, 17 Jul 2018 09:34:45 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531845285; cv=none; d=google.com; s=arc-20160816; b=l6wXiIIkAPFU4ya8kDIRfH4pf8lNjoaEm1w3lT8q2nr8XodJYEliqHBrEo59Sf70eb N/4C6PfCvBEu9PZNAu7Lu5VwCahpioR5tTGCr0JRLw87e3fvfc3nkgR+S9b0lhgNSmlQ Si4ZMKqLL3kF+sQ5r9+Ghj8SkTWxE60Wo6537PZbpLjD3Po6WfRGGyZhBKwR1aldTIdS 3gTlfYtti69lTlv8C0tiljaRWNlhccfpIG7J9JvN74MwV6xxc+N48LDspQio++naPsRL OYCdynEopL3GbipSH+hCA/WRNXSNytzRqGfP4D8YiXLMK8t4o1WEpnZ1ympFLXRyquOA IBrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=ouFdEy7ZFuXzYSqTTmsyK7Ngb0HiOU4yjxlXi58JiI8=; b=CDZh5RxTgxQU/vlhOZHEbx0R2MpaIztWOKcP4IUlF/5hg6NW9P+9PgHgdNhteCY2hF 19+GLU+LiMxPy975eCsKEwTsmQHzV2NhYxYAPJ+IdE3FPwt0Q9TIFs7XZrdJSwiJdSkW bCLxZt6+MA/I8RLrOmLS17G4LP8gxfxFq1M3MhtoPqOuQo2AXmytaA2DwuF/5L0odwyy BvV+kVpiArsYFGYVrH0ir/KBB5N+LnN+kvaGO9VQQTcTT50QaI3DGxsWEwngqV+wSttC wtjqaPnZkGJMaabUyqgCJ5oyhZ8j3cNJnGTMK3LhiMbbFV/qICeKZ7f1DQn48l35H5gp TdpQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o61-v6si1179877pld.109.2018.07.17.09.34.30; Tue, 17 Jul 2018 09:34:45 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729973AbeGQRHD (ORCPT + 99 others); Tue, 17 Jul 2018 13:07:03 -0400 Received: from pio-pvt-msa2.bahnhof.se ([79.136.2.41]:40682 "EHLO pio-pvt-msa2.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729620AbeGQRHD (ORCPT ); Tue, 17 Jul 2018 13:07:03 -0400 Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa2.bahnhof.se (Postfix) with ESMTP id 594D83F428; Tue, 17 Jul 2018 18:33:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at bahnhof.se Received: from pio-pvt-msa2.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa2.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id suxv1dsbpikH; Tue, 17 Jul 2018 18:33:32 +0200 (CEST) Received: from localhost.localdomain (h-155-4-135-114.NA.cust.bahnhof.se [155.4.135.114]) (Authenticated sender: mb547485) by pio-pvt-msa2.bahnhof.se (Postfix) with ESMTPA id 1BB013F32B; Tue, 17 Jul 2018 18:33:31 +0200 (CEST) Date: Tue, 17 Jul 2018 18:33:30 +0200 From: Fredrik Noring To: Christoph Hellwig Cc: Robin Murphy , m.szyprowski@samsung.com, Geoff Levand , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, JuergenUrban@gmx.de Subject: Re: [PATCH] dma-mapping: Relax warnings for per-device areas Message-ID: <20180717163330.GE2342@localhost.localdomain> References: <1f8262d206c6886072d04cc93454f6e3f812bd20.1530623284.git.robin.murphy@arm.com> <20180705193613.GA28905@lst.de> <20180715122826.GB2342@localhost.localdomain> <20180717145725.GA22109@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180717145725.GA22109@lst.de> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, Geoff, [ CC-ing Geoff to give him an opportunity to chime in about the PS3 part. ] > > Here are three other regressions related to the coherent mask WARN_ON_ONCE: > > They are a pretty strong indication that yes, you should really set > the coherent mask if you ever do coherent allocations.. I'm unfortunately unfamiliar with the USB drivers for the PS3. Geoff, what do you think about setting a coherent mask? Christoph, what mask value would you suggest for the PS2 driver? Typical DMA addresses 0-0x200000 are mapped to 0x1c000000-0x1c200000 and is memory managed exclusively by the IOP. Robin indicated that DMA_BIT_MASK(20) or a nonzero but useless value such as 1 are possibly candidates. It seems quite unclear what the coherent mask actually means in this case, doesn't it? Fredrik