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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 56219C7618B for ; Tue, 23 Jul 2019 14:33:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2EA28218EA for ; Tue, 23 Jul 2019 14:33:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bXD8Jml8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EA28218EA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hYRm9MztQzIT/AhEDxxxRlzXMcNm1z4VHtzA5lzGo4U=; b=bXD8Jml8N+fVPL tEXEBqeHdqAL1EmncX82dru+7tf43X+AogggnCE2t+WB4DydRLIqFrnqsV2g5zROkxqLmLoZQ7ZIU u+368wz3VfnHqMRj+BQePGS60gtTbd4frRiJqwe3MygozItsrXII1/JNwLPfo91EfLn8PUy6IF2yZ oGTL4aRg6EJhVvCRTqb0pnWAOh+60IfMuxclombbRUyu2IKJrGQGG18r21kRXL8KfliYLkfsC7jjj P2IeO6aFY+k7Mpf+RndsWlNCHNS/bpa21NRbgkRqvxEyQ/ZQtOldz1aXlUtPrlowNbq33w/8V1WQZ 7osHjNlq3fcWTZE2glUg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpvrM-0004GG-LD; Tue, 23 Jul 2019 14:33:44 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hpvrJ-0004FY-7e; Tue, 23 Jul 2019 14:33:42 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 4351B68BFE; Tue, 23 Jul 2019 16:33:37 +0200 (CEST) Date: Tue, 23 Jul 2019 16:33:36 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH 00/18] ARM: Add minimal Raspberry Pi 4 support Message-ID: <20190723143336.GA32294@lst.de> References: <1563774880-8061-1-git-send-email-wahrenst@gmx.net> <96113adb5fcab9c2f4bb5fa82b84ff5f9c07fd07.camel@suse.de> <20190723093442.GA27239@lst.de> <04c5eaa03f3a124dbbce6186e11e19acc4539cc8.camel@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <04c5eaa03f3a124dbbce6186e11e19acc4539cc8.camel@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190723_073341_426755_0BA1BEC9 X-CRM114-Status: GOOD ( 12.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Ulf Hansson , Florian Fainelli , Scott Branden , Michael Turquette , Stephen Boyd , Ray Jui , Linus Walleij , linux-mmc@vger.kernel.org, Adrian Hunter , Rob Herring , Eric Anholt , Matthias Brugger , bcm-kernel-feedback-list@broadcom.com, Stefan Wahren , linux-gpio@vger.kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 23, 2019 at 03:32:11PM +0200, Nicolas Saenz Julienne wrote: > You state in "arm: use swiotlb for bounce buffer on LPAE configs" that "The DMA > API requires that 32-bit DMA masks are always supported". If I understand it > correctly this device breaks that assumption. Which implies we need a bounce > buffer system in place for any straming DMA user. Yes, you do. > It seems we're unable to use dma-direct/swiotlb, so I enabled arm's dmabounce > on all devices hooked into RPi's limited interconnect, which fixes this issue. > Any thoughts on this? There is no reason swiotlb could not handle the case, but at least for now dmabounce seems like the better option given that it is well integrated into the arm code. Your patch looks good to me. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel