From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-f177.google.com ([209.85.217.177]:50481 "EHLO mail-lb0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbaLRRlA (ORCPT ); Thu, 18 Dec 2014 12:41:00 -0500 Received: by mail-lb0-f177.google.com with SMTP id b6so1338633lbj.22 for ; Thu, 18 Dec 2014 09:40:59 -0800 (PST) Message-ID: <549311A9.8050909@cogentembedded.com> Date: Thu, 18 Dec 2014 20:40:57 +0300 From: Sergei Shtylyov MIME-Version: 1.0 To: Ben Hutchings , linux-media@vger.kernel.org CC: Guennadi Liakhovetski , linux-kernel@codethink.co.uk, William Towle , Hans Verkuil Subject: Re: [RFC PATCH 3/5] media: rcar_vin: Fix race condition terminating stream References: <1418914070.22813.13.camel@xylophone.i.decadent.org.uk> <1418914186.22813.16.camel@xylophone.i.decadent.org.uk> In-Reply-To: <1418914186.22813.16.camel@xylophone.i.decadent.org.uk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hello. On 12/18/2014 05:49 PM, Ben Hutchings wrote: > From: Ian Molton > This patch fixes a race condition whereby a frame being captured may generate an > interrupt between requesting capture to halt and freeing buffers. No need for the leading space. > This condition is exposed by the earlier patch that explicitly calls > vb2_buffer_done() during stop streaming. Hm, perhaps for the sake of bisection, these 2 patches need to be merged? > The solution is to wait for capture to finish prior to finalising these buffers. > Signed-off-by: Ian Molton > Signed-off-by: William Towle > --- > drivers/media/platform/soc_camera/rcar_vin.c | 43 +++++++++++++++++--------- > 1 file changed, 28 insertions(+), 15 deletions(-) > diff --git a/drivers/media/platform/soc_camera/rcar_vin.c b/drivers/media/platform/soc_camera/rcar_vin.c > index 7069176..b234e57 100644 > --- a/drivers/media/platform/soc_camera/rcar_vin.c > +++ b/drivers/media/platform/soc_camera/rcar_vin.c [...] > @@ -465,7 +488,6 @@ static void rcar_vin_videobuf_release(struct vb2_buffer *vb) > struct rcar_vin_priv *priv = ici->priv; > unsigned int i; > int buf_in_use = 0; > - Unrelated white space change. Moreover, there should be an empty line after declarations. > spin_lock_irq(&priv->lock); > > /* Is the buffer in use by the VIN hardware? */ [...] > @@ -520,12 +530,15 @@ static void rcar_vin_stop_streaming(struct vb2_queue *vq) > > spin_lock_irq(&priv->lock); > > + rcar_vin_wait_stop_streaming(priv); > + > for (i = 0; i < vq->num_buffers; ++i) > if (vq->bufs[i]->state == VB2_BUF_STATE_ACTIVE) > vb2_buffer_done(vq->bufs[i], VB2_BUF_STATE_ERROR); > > list_for_each_safe(buf_head, tmp, &priv->capture) > list_del_init(buf_head); > + Also seems like unrelated whitespace cleanup. > spin_unlock_irq(&priv->lock); > } WBR, Sergei