From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benoit Parrot , Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH 4.2 070/134] [media] media: am437x-vpfe: Fix a race condition during release Date: Sat, 26 Sep 2015 13:55:22 -0700 Message-Id: <20150926205316.033254699@linuxfoundation.org> In-Reply-To: <20150926205311.819185658@linuxfoundation.org> References: <20150926205311.819185658@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benoit Parrot commit c99235fa3ef833c3c23926085f2bb68851c8460a upstream. 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") Signed-off-by: Benoit Parrot Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/am437x/am437x-vpfe.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/drivers/media/platform/am437x/am437x-vpfe.c +++ b/drivers/media/platform/am437x/am437x-vpfe.c @@ -1186,14 +1186,24 @@ static int vpfe_initialize_device(struct 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;