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=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 D5C06C433E1 for ; Fri, 21 Aug 2020 17:04:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD03E20656 for ; Fri, 21 Aug 2020 17:04:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="x1UiSShY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728269AbgHURDt (ORCPT ); Fri, 21 Aug 2020 13:03:49 -0400 Received: from crapouillou.net ([89.234.176.41]:60498 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728358AbgHURCM (ORCPT ); Fri, 21 Aug 2020 13:02:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1598029328; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ug5gxRXWAmpM8XNioOeKclYiEPP4BbU07uhWjR3Ug9Q=; b=x1UiSShYKhNWkYR4fQ4NnNOx3XVOyC4J+Uz2YQHTAnKh/JxvHpm9QtgSjOtpAdZOiMnO0e 7T6i334G567SO96AIU6yNxNwTGC/AI4+5imcJfDekHDN5JDlFPplnW903jV5n7taNgCDwC ykVqnCCQ5EHDAvi9htZfbLUidHoW9DA= Date: Fri, 21 Aug 2020 19:01:57 +0200 From: Paul Cercueil Subject: Re: [PATCH v2] drivers/dma/dma-jz4780: Fix race condition between probe and irq handler To: madhuparnabhowmik10@gmail.com Cc: vkoul@kernel.org, dan.j.williams@intel.com, lars@metafoo.de, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, andrianov@ispras.ru, ldv-project@linuxtesting.org Message-Id: <9BBFFQ.4DKVQYU5BDCT1@crapouillou.net> In-Reply-To: <20200821034423.12713-1-madhuparnabhowmik10@gmail.com> References: <20200821034423.12713-1-madhuparnabhowmik10@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Le ven. 21 ao=FBt 2020 =E0 9:14, madhuparnabhowmik10@gmail.com a =E9crit : > From: Madhuparna Bhowmik >=20 > In probe, IRQ is requested before zchan->id is initialized which can=20 > be > read in the irq handler. Hence, shift request irq after other=20 > initializations > complete. >=20 > Found by Linux Driver Verification project (linuxtesting.org). >=20 > Signed-off-by: Madhuparna Bhowmik Reviewed-by: Paul Cercueil Thanks for the patch. Cheers, -Paul >=20 > --- > Changes since v1: > Keep enable clock before request IRQ. > --- > drivers/dma/dma-jz4780.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) >=20 > diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c > index 448f663da89c..8beed91428bd 100644 > --- a/drivers/dma/dma-jz4780.c > +++ b/drivers/dma/dma-jz4780.c > @@ -879,24 +879,11 @@ static int jz4780_dma_probe(struct=20 > platform_device *pdev) > return -EINVAL; > } >=20 > - ret =3D platform_get_irq(pdev, 0); > - if (ret < 0) > - return ret; > - > - jzdma->irq =3D ret; > - > - ret =3D request_irq(jzdma->irq, jz4780_dma_irq_handler, 0,=20 > dev_name(dev), > - jzdma); > - if (ret) { > - dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); > - return ret; > - } > - > jzdma->clk =3D devm_clk_get(dev, NULL); > if (IS_ERR(jzdma->clk)) { > dev_err(dev, "failed to get clock\n"); > ret =3D PTR_ERR(jzdma->clk); > - goto err_free_irq; > + return ret; > } >=20 > clk_prepare_enable(jzdma->clk); > @@ -949,10 +936,23 @@ static int jz4780_dma_probe(struct=20 > platform_device *pdev) > jzchan->vchan.desc_free =3D jz4780_dma_desc_free; > } >=20 > + ret =3D platform_get_irq(pdev, 0); > + if (ret < 0) > + goto err_disable_clk; > + > + jzdma->irq =3D ret; > + > + ret =3D request_irq(jzdma->irq, jz4780_dma_irq_handler, 0,=20 > dev_name(dev), > + jzdma); > + if (ret) { > + dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); > + goto err_disable_clk; > + } > + > ret =3D dmaenginem_async_device_register(dd); > if (ret) { > dev_err(dev, "failed to register device\n"); > - goto err_disable_clk; > + goto err_free_irq; > } >=20 > /* Register with OF DMA helpers. */ > @@ -960,17 +960,17 @@ static int jz4780_dma_probe(struct=20 > platform_device *pdev) > jzdma); > if (ret) { > dev_err(dev, "failed to register OF DMA controller\n"); > - goto err_disable_clk; > + goto err_free_irq; > } >=20 > dev_info(dev, "JZ4780 DMA controller initialised\n"); > return 0; >=20 > -err_disable_clk: > - clk_disable_unprepare(jzdma->clk); > - > err_free_irq: > free_irq(jzdma->irq, jzdma); > + > +err_disable_clk: > + clk_disable_unprepare(jzdma->clk); > return ret; > } >=20 > -- > 2.17.1 >=20