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 D64B7C432C3 for ; Tue, 3 Dec 2019 13:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F2D32073B for ; Tue, 3 Dec 2019 13:04:55 +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="M8Y595qc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726131AbfLCNEz (ORCPT ); Tue, 3 Dec 2019 08:04:55 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:49612 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbfLCNEz (ORCPT ); Tue, 3 Dec 2019 08:04:55 -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=swPLnU+mch3Xmy4l4gNFvfkSplS5ugsR2ljdaAIZq+8=; b=M8Y595qcM8HSiDgNNG6dYczb2 Pe72oiN1OM/5miwYjnPRYyA5q8yeDzR7UFs4AAMtsVL1+/fNGhCAPTsfr3FCkoCBMoXkYXSI5koN0 l9XuGn7bW6uVNKxP+tj3igXUgjA4azjLqLFLyjaWfYL2SSHfU5xhN94rai6/14NcUyCimhCYE/TPm KFCW8HvCR3TZxuVhLcdawgyxvh7zBmKD4lHI/spONN5RXJgaGiwJCfeqxBKudY/3DErZYB7jGfGBl Rnt4mef3hh9g3Puw2CZnD7oQjp4Eji1VNeQYBE38NpQ24rk0lKKgn1YUIaTCsYyVdZiTpUARwOiOF q6yFB7t8w==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic7rF-00074e-57; Tue, 03 Dec 2019 13:04:49 +0000 Date: Tue, 3 Dec 2019 05:04:49 -0800 From: Christoph Hellwig To: Jisheng Zhang Cc: Jun Nie , Christoph Hellwig , "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" Subject: Re: [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround Message-ID: <20191203130449.GA20607@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> <20191203173256.55f527d5@xhacker.debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191203173256.55f527d5@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: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Dec 03, 2019 at 09:49:33AM +0000, Jisheng Zhang wrote: > > can't work. I'm not sure I understand blk_queue_segment_boundary() properly. > > May Christoph help to clarify? > > what's more, not all scatterlist in mmc are from block layer, for example, > __mmc_blk_ioctl_cmd(), mmc_test.c etc.. > > How do we ensure the boundary is fine in these cases? By using block layer passthrough requests (REQ_OP_DRV*). Otherwise any other I/O limit imposed by the driver is ignored as well.