From patchwork Fri Dec 13 05:52:46 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Jiada" X-Patchwork-Id: 3338331 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 00FC29F44E for ; Fri, 13 Dec 2013 05:53:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2D39A207CE for ; Fri, 13 Dec 2013 05:53:40 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3415E207C3 for ; Fri, 13 Dec 2013 05:53:39 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VrLgt-00036A-5d; Fri, 13 Dec 2013 05:53:35 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VrLgq-0005VD-Mg; Fri, 13 Dec 2013 05:53:32 +0000 Received: from relay1.mentorg.com ([192.94.38.131]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VrLgn-0005UQ-1S for linux-arm-kernel@lists.infradead.org; Fri, 13 Dec 2013 05:53:29 +0000 Received: from svr-orw-exc-10.mgc.mentorg.com ([147.34.98.58]) by relay1.mentorg.com with esmtp id 1VrLgM-0005H6-06 from Jiada_Wang@mentor.com ; Thu, 12 Dec 2013 21:53:02 -0800 Received: from NA1-MAIL.mgc.mentorg.com ([147.34.98.181]) by SVR-ORW-EXC-10.mgc.mentorg.com with Microsoft SMTPSVC(6.0.3790.4675); Thu, 12 Dec 2013 21:53:01 -0800 Received: from ubuntu.localdomain ([134.86.193.47]) by NA1-MAIL.mgc.mentorg.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 12 Dec 2013 21:53:00 -0800 From: jiada_wang@mentor.com To: shawn.guo@linaro.org, b32955@freescale.com Subject: [PATCH] dma: imx: correct sdmac->status for cyclic dma tx Date: Thu, 12 Dec 2013 21:52:46 -0800 Message-Id: <1386913966-20595-1-git-send-email-jiada_wang@mentor.com> X-Mailer: git-send-email 1.8.5 X-OriginalArrivalTime: 13 Dec 2013 05:53:01.0284 (UTC) FILETIME=[9520F240:01CEF7C7] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131213_005329_136014_66122E0D X-CRM114-Status: UNSURE ( 8.54 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -1.9 (-) Cc: linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jiada Wang In cyclic dma tx's handler sdma_handle_channel_loop(), SDMA channel statue is set to either DMA_ERROR or DMA_IN_PROGRESS based on each period's status. This has the following issues: 1) If one period's status is BD_RROR, then channel status will be set to DMA_ERROR, but it will be overwritten to DMA_IN_PROGRESS if the following periods are OK. 2) DMA client may call sdma_control(DMA_TERMINATE_ALL) to stop the cyclic dma operation, sdma channel status will be set to DMA_ERROR, but if after this handler is called, then again the channel status will be overwritten to DMA_IN_PROGRESS. Then the following dmaengine_prep_dma_cyclic() will always fail, as channel status is DMA_IN_PROGRESS. As in cyclic dma tx, channel status will be initially set to DMA_IN_PROGRESS, driver only needs to change it to DMA_ERROR, when something wrong happens (one period status is wrong, or stoped by client explicitly). Signed-off-by: Jiada Wang --- drivers/dma/imx-sdma.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index c75679d..c8a0094 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -605,8 +605,6 @@ static void sdma_handle_channel_loop(struct sdma_channel *sdmac) if (bd->mode.status & BD_RROR) sdmac->status = DMA_ERROR; - else - sdmac->status = DMA_IN_PROGRESS; bd->mode.status |= BD_DONE; sdmac->buf_tail++;