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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9BF03C433E0 for ; Mon, 4 Jan 2021 17:17:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D4E9224D4 for ; Mon, 4 Jan 2021 17:17:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727373AbhADRRk convert rfc822-to-8bit (ORCPT ); Mon, 4 Jan 2021 12:17:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbhADRRk (ORCPT ); Mon, 4 Jan 2021 12:17:40 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2866DC061794 for ; Mon, 4 Jan 2021 09:17:00 -0800 (PST) Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kwTTW-0004IN-QO; Mon, 04 Jan 2021 18:16:58 +0100 Received: from pza by lupine with local (Exim 4.92) (envelope-from ) id 1kwTTW-00015u-2u; Mon, 04 Jan 2021 18:16:58 +0100 Message-ID: Subject: Re: [PATCH 1/3] media: imx: Unregister csc/scaler only if registered From: Philipp Zabel To: Ezequiel Garcia , linux-media@vger.kernel.org, Hans Verkuil Cc: kernel@collabora.com, Laurent Pinchart , Steve Longerbeam , NXP Linux Team Date: Mon, 04 Jan 2021 18:16:57 +0100 In-Reply-To: <20201228122131.138454-1-ezequiel@collabora.com> References: <20201228122131.138454-1-ezequiel@collabora.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-media@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Ezequiel, On Mon, 2020-12-28 at 09:21 -0300, Ezequiel Garcia wrote: > The csc/scaler device pointer (imxmd->m2m_vdev) is assigned > after the imx media device v4l2-async probe completes, > therefore we need to check if the device is non-NULL > before trying to unregister it. > > This can be the case if the non-completed imx media device > is unbinded (or the driver is removed), leading to a kernel oops. > > Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") > Signed-off-by: Ezequiel Garcia > --- > drivers/staging/media/imx/imx-media-dev.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c > index 6d2205461e56..b6d5f844ad79 100644 > --- a/drivers/staging/media/imx/imx-media-dev.c > +++ b/drivers/staging/media/imx/imx-media-dev.c > @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev) > > v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n"); > > + if (imxmd->m2m_vdev) { Thank you, it's even worse. If imx_media_csc_scaler_device_init() fails in imx6_media_probe_complete(), imxmd->m2m_vdev contains an error value. So either this should check if (!IS_ERR_OR_NULL(imxmd->m2m_vdev)) or (probably better) probe_complete should be changed as well. > + imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); > + imxmd->m2m_vdev = NULL; > + } > + > v4l2_async_notifier_unregister(&imxmd->notifier); > imx_media_unregister_ipu_internal_subdevs(imxmd); > v4l2_async_notifier_cleanup(&imxmd->notifier); > - imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); > media_device_unregister(&imxmd->md); > v4l2_device_unregister(&imxmd->v4l2_dev); > media_device_cleanup(&imxmd->md); regards Philipp