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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 3DB91C432C0 for ; Tue, 3 Dec 2019 13:06:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 122D2206EC for ; Tue, 3 Dec 2019 13:06:13 +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="ENkvTP7/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725957AbfLCNGN (ORCPT ); Tue, 3 Dec 2019 08:06:13 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:52208 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbfLCNGN (ORCPT ); Tue, 3 Dec 2019 08:06:13 -0500 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=nB+RFuMx6p+ckuFU7XT4n9LRqqE+cpEgvTBUwrwJ8BQ=; b=ENkvTP7/SADn+Vrs/m/95i8on Q0D1kUNIgud/Ip202gJZ1OHdzB+AA034RXVtOjN+em2vaxQEBAvHVcdycQgD8kvUccbDV1Kqgdo6f NaxTzcU/Siv1d7Sz62ZScvTBWMtDw+7ev8vVcSMXAtNN5s7g9F/2MKSuJ1Jhpw6lW+Ishw3iq2/Nj XX1ou+pTsQbCWcVAVEX3AnREDHqHPFW2cK5EnfRwVfO6AlPDXq3h62LMTbAltYgERyM1CLJmjp65o qWtnzXwPqwvCzQ9/NuED3R3xuUbieb9bUX7yffTTJN2GIJ+2eEKle7x4ODrtkazFc2lEQPUS8no6Z 5ienkSB/A==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic7sX-0000aC-BW; Tue, 03 Dec 2019 13:06:09 +0000 Date: Tue, 3 Dec 2019 05:06:09 -0800 From: Christoph Hellwig To: Jisheng Zhang Cc: Christoph Hellwig , Jun Nie , "ulf.hansson@linaro.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "adrian.hunter@intel.com" , "linux-mmc@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-ide@vger.kernel.org" Subject: Re: [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround Message-ID: <20191203130609.GA2144@infradead.org> References: <20191202144104.5069-1-jun.nie@linaro.org> <20191202144104.5069-5-jun.nie@linaro.org> <20191203103320.273a7309@xhacker.debian> <20191203165123.4e6f9e28@xhacker.debian> <20191203091824.GA4685@infradead.org> <20191203172434.39b2c2c2@xhacker.debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191203172434.39b2c2c2@xhacker.debian> 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-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On Tue, Dec 03, 2019 at 09:49:49AM +0000, Jisheng Zhang wrote: > > As in exactly one boundary and not an alignment? Where the one > > boundary is not a power of two and thus can't be expressed? > > Take drivers/mmc/host/sdhci-of-dwcmshc.c for example, target physical DMA addr > can't span 128MB, 256MB, 128*3MB, ...128*nMB > > I'm not sure whether blk_queue_segment_boundary could solve this limitation. That is exaxtly the kind of limitation blk_queue_segment_boundary is intended for.