From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-3.sys.kth.se ([130.237.48.192]:42965 "EHLO smtp-3.sys.kth.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751999AbdEOXLn (ORCPT ); Mon, 15 May 2017 19:11:43 -0400 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= To: Vinod Koul , dmaengine@vger.kernel.org, linux-renesas-soc@vger.kernel.org Cc: Yoshihiro Shimoda , Lars-Peter Clausen , Hiroyuki Yokoyama , Geert Uytterhoeven , Laurent Pinchart , =?UTF-8?q?Niklas=20S=C3=B6derlund?= Subject: [PATCH v2 2/3] dmaengine: rcar-dmac: implement device_synchronize() Date: Tue, 16 May 2017 01:09:16 +0200 Message-Id: <20170515230917.31888-3-niklas.soderlund+renesas@ragnatech.se> In-Reply-To: <20170515230917.31888-1-niklas.soderlund+renesas@ragnatech.se> References: <20170515230917.31888-1-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Implement the device_synchronize() callback which wait until a dma channel is stopped to provide a synchronization point. This protects the driver from multiple race conditions when terminating and freeing resources. E.g. the completion callback still running after device_terminate_all() has completed. Signed-off-by: Niklas Söderlund --- drivers/dma/sh/rcar-dmac.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index c68c3336bdad44df..fb07cd5fe77b3c43 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -1365,6 +1365,13 @@ static void rcar_dmac_issue_pending(struct dma_chan *chan) spin_unlock_irqrestore(&rchan->lock, flags); } +static void rcar_dmac_device_synchronize(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + + synchronize_irq(rchan->irq); +} + /* ----------------------------------------------------------------------------- * IRQ handling */ @@ -1846,6 +1853,7 @@ static int rcar_dmac_probe(struct platform_device *pdev) engine->device_terminate_all = rcar_dmac_chan_terminate_all; engine->device_tx_status = rcar_dmac_tx_status; engine->device_issue_pending = rcar_dmac_issue_pending; + engine->device_synchronize = rcar_dmac_device_synchronize; ret = dma_async_device_register(engine); if (ret < 0) -- 2.13.0