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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D30FBC433FE for ; Mon, 28 Mar 2022 14:59:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244211AbiC1PB0 (ORCPT ); Mon, 28 Mar 2022 11:01:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229673AbiC1PBX (ORCPT ); Mon, 28 Mar 2022 11:01:23 -0400 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E5C92D1C9; Mon, 28 Mar 2022 07:59:42 -0700 (PDT) Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 22SDsu15025436; Mon, 28 Mar 2022 16:59:07 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=kltjsirzntSwfHTV/4WKoQM0uiln7XLsDRSP3qmSBh4=; b=NecfBsKyQWBqiXma1Zhw2cVJtVl4UDOKML7BTAe3e+LFAcTdfXlyw7wklCzcffFl/EDp rSyYsr6Irm3guATATSJnlScoZDze8MKQAUzD73gV/CVt5XOl91XVuLu5E8KRLC1iZXyN ctiHoAjA4oy5Tc2npoOG5dLc1f9k9JoCbc8sa066ciP2XwmPPnwd6ASka2hD0tBrNcpj M5gOYnzVCzR06iV7BjkQdTNhnrX6LWS3LEZGhMXkxiWXt6Ypck4UgYtve25lGkEGmx58 kY9D7nQU2JTpeA/AKR/eRLS0OcDWs0X3Lc0SGhgLk3QCqqgkroGdaxnEKSRsGWVIVZX2 ug== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3f1tkm3ec9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 28 Mar 2022 16:59:07 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id EE38110002A; Mon, 28 Mar 2022 16:59:05 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id D9521235F0D; Mon, 28 Mar 2022 16:59:05 +0200 (CEST) Received: from [10.201.21.172] (10.75.127.49) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Mon, 28 Mar 2022 16:59:04 +0200 Message-ID: <0d0653d4-8272-7052-e0c5-447506a13a64@foss.st.com> Date: Mon, 28 Mar 2022 16:58:52 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 1/3] dt-bindings: mmc: mmci: add a property to disable DMA LLI Content-Language: en-US To: Linus Walleij CC: Rob Herring , Ulf Hansson , , , , , , Alexandre Torgue , Christophe Kerello , Ludovic Barre , Maxime Coquelin , Philipp Zabel , Russell King , Marek Vasut , , Manivannan Sadhasivam , Grzegorz Szymaszek References: <20220304135134.47827-1-yann.gautier@foss.st.com> <20220304135134.47827-2-yann.gautier@foss.st.com> <0bc53018-fce4-4104-fa47-6e60d2367d69@foss.st.com> From: Yann Gautier In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.49] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.850,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-28_06,2022-03-28_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/25/22 21:12, Linus Walleij wrote: > On Tue, Mar 15, 2022 at 9:26 AM Yann Gautier wrote: > >> The STM32 variant uses an internal DMA, and the DMA functions are in its >> dedicated file. So I was planning to do the same as what is done in >> meson-gx-mmc.c: using a bounce buffer to copy from/to in case DMA >> constraints are not fulfilled. Not sure it can help for Ux500. >> >> Ulf, before I send my new series (although it is not ready yet), would >> you be OK with the bounce buffer idea? > Hi Linus, > Would it not be better if the bounce buffer is something available > for all MMCI variants and not restricted to the STM32 DMA add-on? The issue was seen with the internal DMA of the STM32 variant of PL180. > > What I'm thinking is that this is a problem with the MMCI hardware > rather than with the DMA hardware, so the problem kind of gets > fixed in the wrong place if the bounce buffer is in the DMA add-on > code. > > Maybe this is how you fixed it in later patches, I'll take a look. I've pushed a new version there to correct latest remarks from Ulf: https://lore.kernel.org/all/20220328145114.334577-1-yann.gautier@foss.st.com/ > > Yours, > Linus Walleij Best regards, Yann