Re: [PATCH 2/2] media: v4l: vsp1: Fix uif null pointer access

From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
To: Biju Das <biju.das.jz@bp.renesas.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>
Subject: Re: [PATCH 2/2] media: v4l: vsp1: Fix uif null pointer access
Date: Wed, 10 Mar 2021 14:39:21 +0000	[thread overview]
Message-ID: <56c2d53e-8d1f-5b84-1480-5965ae9cbae2@ideasonboard.com> (raw)
In-Reply-To: <OS0PR01MB5922BE9F9D151623773CF53286919@OS0PR01MB5922.jpnprd01.prod.outlook.com>

Hi Biju,

On 10/03/2021 13:56, Biju Das wrote:
> Hi Kieran,
> 
> Thanks for the feedback.
>> Subject: Re: [PATCH 2/2] media: v4l: vsp1: Fix uif null pointer access
>>
>> Hi Biju,
>>
>> On 01/03/2021 12:08, Biju Das wrote:
>>> RZ/G2L SoC has no UIF. This patch fixes null pointer access, when UIF
>>> module is not used.
>>>
>>> Fixes: 5e824f989e6e8("media: v4l: vsp1: Integrate DISCOM in display
>>> pipeline")
>>> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
>>> ---
>>>  drivers/media/platform/vsp1/vsp1_drm.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/vsp1/vsp1_drm.c
>>> b/drivers/media/platform/vsp1/vsp1_drm.c
>>> index f6d2f47a4058..06f74d410973 100644
>>> --- a/drivers/media/platform/vsp1/vsp1_drm.c
>>> +++ b/drivers/media/platform/vsp1/vsp1_drm.c
>>> @@ -462,9 +462,9 @@ static int vsp1_du_pipeline_setup_inputs(struct
>>> vsp1_device *vsp1,
>>
>>
>> This looks like it complicates these conditionals more than we perhaps
>> need to.
>>
>> What do you think about adding something above the block comment here?:
> 
> It is much better. 
> 
> This patch is accepted in media tree[1]. So not sure,
> should I send a follow up patch as optimization or drop this patch and send new one.

Oh, I didn't realise these were in already. Sorry, I didn't see any
review on the list, and it was the earliest I had got to them.

> Please suggest.

Up to you, I don't think this would get dropped now it's integrated.
It's in, so if you want to update on top I believe that's fine.

--
Kieran

> [1] https://git.linuxtv.org/media_tree.git/commit/?h=fixes&id=c4f27003ec3d84ef0c333c74ae2aff326537e583
> 
> Cheers,
> Biju
> 
>> 	if (!drm_pipe->uif)
>> 		return 0;
>>
>>
>>>  	 * make sure it is present in the pipeline's list of entities if it
>>>  	 * wasn't already.
>>>  	 */
>>> -	if (!use_uif) {
>>> +	if (drm_pipe->uif && !use_uif) {
>>>  		drm_pipe->uif->pipe = NULL;
>>> -	} else if (!drm_pipe->uif->pipe) {
>>> +	} else if (drm_pipe->uif && !drm_pipe->uif->pipe) {>
>> 	drm_pipe->uif->pipe = pipe;
>>>  		list_add_tail(&drm_pipe->uif->list_pipe, &pipe->entities);
>>>  	}
>>>
> 