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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7F5C5C54FCB for ; Fri, 24 Apr 2020 12:31:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5251120736 for ; Fri, 24 Apr 2020 12:31:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587731496; bh=/HD9MmdeIWifWlhK6G1FDWA7NHgdjdefK5EkIy2ZJyk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Bulamif6yrGOG3XA593SsJzg5q4LcUkRrlJLlxBpmDJ72tms/QXiZ0E6tpCEvZU+v dqUGpGQ2pgJ8Bfj8xdowUa0WmznFrHAXvlmAGyJnXKcF9zu/3BaO/sAcEgtFyt9Y9e gnRm5CqOoJk+k8JVzHIURPViH9A/WfZHgo/uMZDg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727878AbgDXMXO (ORCPT ); Fri, 24 Apr 2020 08:23:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:52800 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727872AbgDXMXN (ORCPT ); Fri, 24 Apr 2020 08:23:13 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A7394216FD; Fri, 24 Apr 2020 12:23:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587730993; bh=/HD9MmdeIWifWlhK6G1FDWA7NHgdjdefK5EkIy2ZJyk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CCrakp+oqgOaa6fysldmxy4KTAfwwNRzwxVezEK8FVZSc9Xv/YoxLVq2Qw2LMjXOe 9uSJlMGXOuztcrrQPb23/Vj/PiPjvIJ8pTbUeC8KmjH/mDpGPXAykeX74Vz7wZQ/nb HVXmrivk0Z2JGw0Vm3jeJdjktmpBw41AQI0JfOOA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Osipenko , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 31/38] i2c: tegra: Synchronize DMA before termination Date: Fri, 24 Apr 2020 08:22:29 -0400 Message-Id: <20200424122237.9831-31-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200424122237.9831-1-sashal@kernel.org> References: <20200424122237.9831-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dmitry Osipenko [ Upstream commit 8814044fe0fa182abc9ff818d3da562de98bc9a7 ] DMA transfer could be completed, but CPU (which handles DMA interrupt) may get too busy and can't handle the interrupt in a timely manner, despite of DMA IRQ being raised. In this case the DMA state needs to synchronized before terminating DMA transfer in order not to miss the DMA transfer completion. Signed-off-by: Dmitry Osipenko Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-tegra.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 0daa863fb26f2..0c6dac770fc3a 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -1223,6 +1223,15 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, time_left = tegra_i2c_wait_completion_timeout( i2c_dev, &i2c_dev->dma_complete, xfer_time); + /* + * Synchronize DMA first, since dmaengine_terminate_sync() + * performs synchronization after the transfer's termination + * and we want to get a completion if transfer succeeded. + */ + dmaengine_synchronize(i2c_dev->msg_read ? + i2c_dev->rx_dma_chan : + i2c_dev->tx_dma_chan); + dmaengine_terminate_sync(i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan); -- 2.20.1