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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 96A1BC3524A for ; Tue, 4 Feb 2020 06:52:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65BA021582 for ; Tue, 4 Feb 2020 06:52:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="lEciPoSL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726230AbgBDGwv (ORCPT ); Tue, 4 Feb 2020 01:52:51 -0500 Received: from lelv0142.ext.ti.com ([198.47.23.249]:35690 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725976AbgBDGwv (ORCPT ); Tue, 4 Feb 2020 01:52:51 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 0146qepo081703; Tue, 4 Feb 2020 00:52:40 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1580799160; bh=kqHjON9qr5o5bbhRZyitzLHtPGadeidJrm20nZP2rPw=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=lEciPoSLv6eg/ca444XD396RT1yJylQxslE0enN1iz3KkZSI54RnuZ4mdQrwm5BuT 26NmudokKyzAWXdNvfx+BQB4WqI9S5k4M/E6npfHQjlDcF2AbptZ2LWjJuwkOKsxnc vGpDUBeg+is1H5WTdtjEumucqHabhpC4kDJfs6mY= Received: from DFLE107.ent.ti.com (dfle107.ent.ti.com [10.64.6.28]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 0146qeSX101493 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 4 Feb 2020 00:52:40 -0600 Received: from DFLE107.ent.ti.com (10.64.6.28) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Tue, 4 Feb 2020 00:52:40 -0600 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Tue, 4 Feb 2020 00:52:40 -0600 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 0146qb9Z046269; Tue, 4 Feb 2020 00:52:38 -0600 Subject: Re: [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan() To: Geert Uytterhoeven , John Paul Adrian Glaubitz CC: Andy Shevchenko , Vinod Koul , dmaengine , Linux Kernel Mailing List , Dan Williams , Linux-sh list , Linux-Renesas References: <20200203101806.2441-1-peter.ujfalusi@ti.com> <701ab186-c240-3c37-2c0b-8ac195f8073f@ti.com> <38f686ae-66fa-0e3a-ec2e-a09fc4054ac4@physik.fu-berlin.de> From: Peter Ujfalusi Message-ID: Date: Tue, 4 Feb 2020 08:52:37 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Hi Geert, Adrian, On 03/02/2020 22.34, Geert Uytterhoeven wrote: > Hi Adrian, > > On Mon, Feb 3, 2020 at 9:21 PM John Paul Adrian Glaubitz > wrote: >> On 2/3/20 2:32 PM, Geert Uytterhoeven wrote: >>> Both rspi and sh-msiof have users on legacy SH (i.e. without DT): >> >> FWIW, there is a patch set by Yoshinori Sato to add device tree support >> for classical SuperH hardware. It was never merged, unfortunately :(. > > True. > >>> Anyone who cares for DMA on SuperH? >> >> What is DMA used for on SuperH? Wouldn't dropping it cut support for >> essential hardware features? > > It may make a few things slower. I would not drop DMA support but I would suggest to add dma_slave_map for non DT boot so the _compat() can be dropped. Imho on lower spec SoC (and I believe SuperH is) the DMA makes big difference offloading data movement from the CPU. > Does any of your SuperH boards use DMA? > Anything interesting in /proc or /sys w.r.t. DMA? > > Gr{oetje,eeting}s, > > Geert > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki