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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 EFFF1C636CB for ; Sat, 17 Jul 2021 14:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C616E61001 for ; Sat, 17 Jul 2021 14:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234303AbhGQOvm (ORCPT ); Sat, 17 Jul 2021 10:51:42 -0400 Received: from phobos.denx.de ([85.214.62.61]:48804 "EHLO phobos.denx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234234AbhGQOvm (ORCPT ); Sat, 17 Jul 2021 10:51:42 -0400 Received: from [IPv6:::1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 60F8B80C68; Sat, 17 Jul 2021 16:48:39 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1626533324; bh=HrYp+lDZ9IBbPadiUFrdoTcHaCH/AdtmFONkS2XHVwc=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=WwbSF621mthTB3+1Rc7cabqDIa2Fg+B+356AwMInO9vxxWoPaKFYmPc2p1EWUaQ6F bzK4TUBoDhFGTLf5aH3KVpJQO6C5jJK6ZJwx6YxOMuqzQfBFYfv/3fFWLUZb8Y4Us2 fMnTKdKHW/vR73X7IAX+wr6pmG/85RFPbjXLq6J19WOv6JdmQyQ17ZCui+QtmzR9Cj TXC1OhKRLoF2DzjsoRH792J7nN0fGUjSKpkYbDFIiUZ6dU0VrY4mCfx5W1TUDcaSCI pPbh2T6hXqbRnx59W9aTcwRrra/lqCa+fPS2lHTnThyxxWaqbrWN61lTE4WHDrS3VE y1pDQIpPrUv9A== Subject: Re: [PATCH] dmaengine: xilinx: Add empty device_config function To: Vinod Koul Cc: dmaengine@vger.kernel.org, Akinobu Mita , Kedareswara rao Appana , Michal Simek , Vinod Koul References: <20210716182241.218705-1-marex@denx.de> From: Marek Vasut Message-ID: <0aa86cfb-09e7-df99-1a28-dd9086d64058@denx.de> Date: Sat, 17 Jul 2021 16:48:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 7/17/21 4:34 PM, Vinod Koul wrote: > On 17-07-21, 14:01, Marek Vasut wrote: >> On 7/17/21 1:36 PM, Vinod Koul wrote: >>> On 16-07-21, 20:22, Marek Vasut wrote: >>>> Various DMA users call the dmaengine_slave_config() and expect it to >>>> succeed, but that can only succeed if .device_config is implemented. >>>> Add empty device_config function rather than patching all the places >>>> which use dmaengine_slave_config(). >>> >>> .device_config is optional, Yes the dmaengine_slave_config() will check >>> and return error... >>> >>> I think it would make sense to handle this in caller... (ignore >>> ENOSYS..) rather than add a dummy one >> >> That's what I was trying to avoid -- patching all the places in kernel which >> might fail. Why handle it in caller ? > > And how many places would that be..? The xilinx driver using xilinx > dma right> git grep indicates around 170 matches on dmaengine_slave_config. In my case, it is generic PCM DMA in sound/soc/soc-generic-dmaengine-pcm.c . >>>> Signed-off-by: Marek Vasut >>>> Cc: Akinobu Mita >>>> Cc: Kedareswara rao Appana >>>> Cc: Michal Simek >>>> Cc: Vinod Koul >>> >>> ummm..? you really need to update this :) >> >> I had the patch around for a while indeed, it fell through the cracks. > > This has to be more than 3 yrs old then! Four