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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 8E86FC432C0 for ; Tue, 3 Dec 2019 22:58:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 626E8214AF for ; Tue, 3 Dec 2019 22:58:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413907; bh=oU25JYGVk3YLHzHCGmBf/zGRZoUGL5FBoo8Zo7Ay7JQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=USLEU3udHbZv2yhvTj+kPbBzr0okbATW80+Hf2MXrHbhj8uOQ7exPgXS7v8ylVPxY eE6NGCZ0oPAZ2o+i2hzr9yaiDJ1Nkma4d/3ECg0A5U7wA9hT1dK5OfnUA3sMxspjgW JvZbTb2CyQLgYsFDJ8BAoQ3yDztFyf2qY8KorC+c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730648AbfLCW60 (ORCPT ); Tue, 3 Dec 2019 17:58:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:54696 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728692AbfLCW6U (ORCPT ); Tue, 3 Dec 2019 17:58:20 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 E5E0C2053B; Tue, 3 Dec 2019 22:58:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413899; bh=oU25JYGVk3YLHzHCGmBf/zGRZoUGL5FBoo8Zo7Ay7JQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ft/dv0LK553xVLdsZKJubYbR29RYsNBZsWEdL5Kvi1ka3AEM0JVPzxav9ViakQ91u olnaTBVD5oFe4WnmykZKBI6uDMI/u1vqrLKOPRS9GttABe0bF5ELhSngnmZRD3N9DK 0U+M1l65LBBdJ+J6ULx8cVMIFghUV9fGul3KRi1w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hugues Fruchet , Hans Verkuil , Mauro Carvalho Chehab , Mathieu Poirier Subject: [PATCH 4.19 306/321] media: stm32-dcmi: fix DMA corruption when stopping streaming Date: Tue, 3 Dec 2019 23:36:12 +0100 Message-Id: <20191203223443.065564186@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hugues Fruchet commit b3ce6f6ff3c260ee53b0f2236e5fd950d46957da upstream. Avoid call of dmaengine_terminate_all() between dmaengine_prep_slave_single() and dmaengine_submit() by locking the whole DMA submission sequence. Signed-off-by: Hugues Fruchet Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/stm32/stm32-dcmi.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -164,6 +164,9 @@ struct stm32_dcmi { int errors_count; int overrun_count; int buffers_count; + + /* Ensure DMA operations atomicity */ + struct mutex dma_lock; }; static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n) @@ -314,6 +317,13 @@ static int dcmi_start_dma(struct stm32_d return ret; } + /* + * Avoid call of dmaengine_terminate_all() between + * dmaengine_prep_slave_single() and dmaengine_submit() + * by locking the whole DMA submission sequence + */ + mutex_lock(&dcmi->dma_lock); + /* Prepare a DMA transaction */ desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr, buf->size, @@ -322,6 +332,7 @@ static int dcmi_start_dma(struct stm32_d if (!desc) { dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer phy=%pad size=%zu\n", __func__, &buf->paddr, buf->size); + mutex_unlock(&dcmi->dma_lock); return -EINVAL; } @@ -333,9 +344,12 @@ static int dcmi_start_dma(struct stm32_d dcmi->dma_cookie = dmaengine_submit(desc); if (dma_submit_error(dcmi->dma_cookie)) { dev_err(dcmi->dev, "%s: DMA submission failed\n", __func__); + mutex_unlock(&dcmi->dma_lock); return -ENXIO; } + mutex_unlock(&dcmi->dma_lock); + dma_async_issue_pending(dcmi->dma_chan); return 0; @@ -717,7 +731,9 @@ static void dcmi_stop_streaming(struct v spin_unlock_irq(&dcmi->irqlock); /* Stop all pending DMA operations */ + mutex_lock(&dcmi->dma_lock); dmaengine_terminate_all(dcmi->dma_chan); + mutex_unlock(&dcmi->dma_lock); pm_runtime_put(dcmi->dev); @@ -1719,6 +1735,7 @@ static int dcmi_probe(struct platform_de spin_lock_init(&dcmi->irqlock); mutex_init(&dcmi->lock); + mutex_init(&dcmi->dma_lock); init_completion(&dcmi->complete); INIT_LIST_HEAD(&dcmi->buffers);