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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 E5F19C5CFE7 for ; Mon, 9 Jul 2018 17:30:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2D2C20864 for ; Mon, 9 Jul 2018 17:30:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="uXnw6pkh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A2D2C20864 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933968AbeGIRaR (ORCPT ); Mon, 9 Jul 2018 13:30:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:34564 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933479AbeGIR3p (ORCPT ); Mon, 9 Jul 2018 13:29:45 -0400 Received: from localhost (unknown [106.201.46.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 834C6208A5; Mon, 9 Jul 2018 17:29:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1531157385; bh=L6mTdTsEG7kxPYs6X+Y3M0wFuI94a2Yu5AfLGQ1RwwA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uXnw6pkhRe1NKzqZ7wE56NffkQqwwoqTxevF0Y+VjJNCaX6PmWb0w09e+jzLa/dei 9ih8sVrVsqwXGrU27cMbi5oLF0EW7ilJD3oUD1EJCgG0YWQ4GWuZCzlZM/b1nW+i0m 7MNjHmrucI7LUMAcOcZBhWJTncBU5cgoBk65OMvo= Date: Mon, 9 Jul 2018 22:59:37 +0530 From: Vinod To: Marek Szyprowski Cc: dmaengine@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Dan Williams , Lars-Peter Clausen , Mark Brown , Bartlomiej Zolnierkiewicz Subject: Re: [PATCH] dma: add support for reporting pause and resume separately Message-ID: <20180709172937.GP22377@vkoul-mobl> References: <20180702130819eucas1p2e11d8fabec93ba78d9e84f4ca6e5fd65~9jzNWZMqQ1216712167eucas1p27@eucas1p2.samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180702130819eucas1p2e11d8fabec93ba78d9e84f4ca6e5fd65~9jzNWZMqQ1216712167eucas1p27@eucas1p2.samsung.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02-07-18, 15:08, Marek Szyprowski wrote: > 'cmd_pause' DMA channel capability means that respective DMA engine > supports both pausing and resuming given DMA channel. However, in some > cases it is important to know if DMA channel can be paused without the > need to resume it. This is a typical requirement for proper residue > reading on transfer timeout in UART drivers. There are also some DMA > engines with limited hardware, which doesn't really support resuming. > > Reporting pause and resume capabilities separately allows UART drivers to > properly check for the really required capabilities and operate in DMA > mode also in systems with limited DMA hardware. On the other hand drivers, > which rely on full channel suspend/resume support, should now check for > both 'pause' and 'resume' features. > > Existing clients of dma_get_slave_caps() have been checked and the only > driver which rely on proper channel resuming is soc-generic-dmaengine-pcm > driver, which has been updated to check the newly added capability. > Existing 'cmd_pause' now only indicates that DMA engine support pausing > given DMA channel. Applied after fixing the subsystem name, thanks -- ~Vinod