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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B83D0C43381 for ; Thu, 28 Feb 2019 17:11:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E9DC218C3 for ; Thu, 28 Feb 2019 17:11:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733240AbfB1RLR (ORCPT ); Thu, 28 Feb 2019 12:11:17 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:28467 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726093AbfB1RLQ (ORCPT ); Thu, 28 Feb 2019 12:11:16 -0500 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx08-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1SH8Pha008743; Thu, 28 Feb 2019 18:11:07 +0100 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2qtv6d6qv7-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Thu, 28 Feb 2019 18:11:07 +0100 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id B559031; Thu, 28 Feb 2019 17:11:06 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas21.st.com [10.75.90.44]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 97C43A984; Thu, 28 Feb 2019 17:11:06 +0000 (GMT) Received: from SAFEX1HUBCAS22.st.com (10.75.90.93) by SAFEX1HUBCAS21.st.com (10.75.90.44) with Microsoft SMTP Server (TLS) id 14.3.361.1; Thu, 28 Feb 2019 18:11:06 +0100 Received: from localhost (10.201.23.19) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.361.1; Thu, 28 Feb 2019 18:11:05 +0100 From: Hugues Fruchet To: Alexandre Torgue , Mauro Carvalho Chehab , Hans Verkuil CC: , , , , Benjamin Gaignard , Yannick Fertre , Philippe CORNU , "Hugues Fruchet" Subject: [PATCH] media: stm32-dcmi: fix DMA corruption when stopping streaming Date: Thu, 28 Feb 2019 18:10:53 +0100 Message-ID: <1551373853-30222-1-git-send-email-hugues.fruchet@st.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.201.23.19] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-28_09:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/media/platform/stm32/stm32-dcmi.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index f44d8a7..a611a21 100644 --- 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_dcmi *dcmi, 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_dcmi *dcmi, 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_dcmi *dcmi, 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; @@ -720,7 +734,9 @@ static void dcmi_stop_streaming(struct vb2_queue *vq) 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); @@ -1711,6 +1727,7 @@ static int dcmi_probe(struct platform_device *pdev) spin_lock_init(&dcmi->irqlock); mutex_init(&dcmi->lock); + mutex_init(&dcmi->dma_lock); init_completion(&dcmi->complete); INIT_LIST_HEAD(&dcmi->buffers); -- 2.7.4