From patchwork Wed Jul 15 21:00:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benoit Parrot X-Patchwork-Id: 6800611 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 69109C05AC for ; Wed, 15 Jul 2015 21:00:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7FF55206A2 for ; Wed, 15 Jul 2015 21:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0C4120632 for ; Wed, 15 Jul 2015 21:00:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753653AbbGOVAR (ORCPT ); Wed, 15 Jul 2015 17:00:17 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:57215 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753534AbbGOVAQ (ORCPT ); Wed, 15 Jul 2015 17:00:16 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id t6FL0EcD007486; Wed, 15 Jul 2015 16:00:14 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id t6FL0E1q008107; Wed, 15 Jul 2015 16:00:14 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Wed, 15 Jul 2015 15:59:49 -0500 Received: from tct7400.am.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t6FL0D52023263; Wed, 15 Jul 2015 16:00:13 -0500 From: Benoit Parrot To: Hans Verkuil CC: Prabhakar Lad , , , , Benoit Parrot , Subject: [Patch v4] media: am437x-vpfe: Fix a race condition during release Date: Wed, 15 Jul 2015 16:00:06 -0500 Message-ID: <1436994006-10120-1-git-send-email-bparrot@ti.com> X-Mailer: git-send-email 1.8.5.1 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There was a race condition where during cleanup/release operation on-going streaming would cause a kernel panic because the hardware module was disabled prematurely with IRQ still pending. Fixes: 417d2e507edc ("[media] media: platform: add VPFE capture driver support for AM437X") Cc: # v4.0+ Signed-off-by: Benoit Parrot --- Changes since v3: - fix review comment to protect v4l2_fh_is_singular_file() drivers/media/platform/am437x/am437x-vpfe.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c index a30cc2f7e4f1..5ab50c6babe2 100644 --- a/drivers/media/platform/am437x/am437x-vpfe.c +++ b/drivers/media/platform/am437x/am437x-vpfe.c @@ -1185,14 +1185,24 @@ static int vpfe_initialize_device(struct vpfe_device *vpfe) static int vpfe_release(struct file *file) { struct vpfe_device *vpfe = video_drvdata(file); + bool fh_singular; int ret; mutex_lock(&vpfe->lock); - if (v4l2_fh_is_singular_file(file)) - vpfe_ccdc_close(&vpfe->ccdc, vpfe->pdev); + /* Save the singular status before we call the clean-up helper */ + fh_singular = v4l2_fh_is_singular_file(file); + + /* the release helper will cleanup any on-going streaming */ ret = _vb2_fop_release(file, NULL); + /* + * If this was the last open file. + * Then de-initialize hw module. + */ + if (fh_singular) + vpfe_ccdc_close(&vpfe->ccdc, vpfe->pdev); + mutex_unlock(&vpfe->lock); return ret;