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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 5D528C7618B for ; Mon, 29 Jul 2019 06:43:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A4F02073F for ; Mon, 29 Jul 2019 06:43:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564382603; bh=QmVZiVCVVdyuIOIXyrtNlQQDQrcJfU7dMvyEUty+IPs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=oHfKL/qMb8UNpcLfMdUUXYsEkV76tDvfPp3VyoI/mOtG3MTfuzXSqbB7b8IuhI45+ r/XYrfxir6It/7WIX8436p44Ou8PqKTcCX7VhfO7GDYSW5iDqkEMZzkBe4PtegWSlP yEJpmpAAy92hODSI+ciotxd+c3svgQ4BipT2RaE4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726800AbfG2GnX (ORCPT ); Mon, 29 Jul 2019 02:43:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:56784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726088AbfG2GnW (ORCPT ); Mon, 29 Jul 2019 02:43:22 -0400 Received: from localhost (unknown [122.178.221.187]) (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 07343206BA; Mon, 29 Jul 2019 06:43:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564382601; bh=QmVZiVCVVdyuIOIXyrtNlQQDQrcJfU7dMvyEUty+IPs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bXmWlhMvHD6xcN7+Lm31x5rEuncHMBalyOq4wY58j5IQwnZlqAxmMNk07LDjFW0rW 9PtitSv8mvAKbxYNAy+sRyyKM9BBl69xaBafwpwMD/GMF22lL2DJnwJh0KFCPVZFEW GL9ohHYcA81k0qzR9AA+p4+J8pfKH/mziknK4m2k= Date: Mon, 29 Jul 2019 12:12:09 +0530 From: Vinod Koul To: Peter Ujfalusi Cc: dan.j.williams@intel.com, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org Subject: Re: [PATCH v5 0/3] dmaengine: ti: edma: Polled completion support Message-ID: <20190729064209.GF12733@vkoul-mobl.Dlink> References: <20190716082655.1620-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190716082655.1620-1-peter.ujfalusi@ti.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 16-07-19, 11:26, Peter Ujfalusi wrote: > Hi, > > Changes since v4: > - Split the DMA_COMPLETE and !txstate check as Vinod suggested > > Change since v3: > - fix DMA pointer tracking for memcpy > - completion polling is only done when it is asked by not providing > DMA_PREP_INTERRUPT for memcpy > > Changes since v2: > - Fix typo in the comment for patch 0 > > Changes since v1: > - Cleanup patch for the array register handling > - typo fixed in patch2 commit message > > The code around the array register access was pretty confusing for the first > look, so clean them up first then use the cleaner way in the polled handling. > > When a DMA client driver does not set the DMA_PREP_INTERRUPT because it > does not want to use interrupts for DMA completion or because it can not > rely on DMA interrupts due to executing the memcpy when interrupts are > disabled it will poll the status of the transfer. > > Since we can not tell from any EDMA register that the transfer is > completed, we can only know that the paRAM set has been sent to TPTC for > processing we need to check the residue of the transfer, if it is 0 then > the transfer is completed. > > The polled completion can bve tested by applying: > https://patchwork.kernel.org/patch/10966499/ > > Enabling the memcpy for EDMA and run the dmatest with polled = 1. > > Or, enable the EDMA memcpy support and boot up any dra7 family device with > display enabled. The workaround for DMM errata i878 uses polled DMA memcpy. Applied, thanks. Fixed typo in 2nd patch while at it -- ~Vinod