linux-kernel - Re: [PATCH] solo6x10: just pass frame motion flag from hardware, drop additional handling as complicated and unstable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5465E337.6020808@xs4all.nl>
Date:	Fri, 14 Nov 2014 12:10:47 +0100
From:	Hans Verkuil <hverkuil@...all.nl>
To:	Andrey Utkin <andrey.utkin@...p.bluecherry.net>,
	linux-kernel@...r.kernel.org, linux-media@...r.kernel.org
CC:	m.chehab@...sung.com, hans.verkuil@...co.com
Subject: Re: [PATCH] solo6x10: just pass frame motion flag from hardware,
 drop additional handling as complicated and unstable

Hi Andrew,

FYI: I need to test this myself and understand it better, so it will take some
time before I get to this. It is in my TODO list, so it won't be forgotten.

Regards,

	Hans

On 11/05/2014 09:11 PM, Andrey Utkin wrote:
> Dropping code (introduced in 316d9e84a72069e04e483de0d5934c1d75f6a44c)
> which intends to make raising of motion events more "smooth"(?).
> 
> It made motion event never appear in my installation.
> That code is complicated, so I couldn't figure out quickly how to fix
> it, so dropping it seems better to me.
> 
> Another justification is that anyway application would implement
> "motion signal stabilization" if required, it is not necessarily kernel
> driver's job.
> 
> Signed-off-by: Andrey Utkin <andrey.utkin@...p.bluecherry.net>
> ---
>  drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c | 30 +-------------------------
>  drivers/media/pci/solo6x10/solo6x10.h          |  2 --
>  2 files changed, 1 insertion(+), 31 deletions(-)
> 
> diff --git a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> index 30e09d9..866f7b3 100644
> --- a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> @@ -239,8 +239,6 @@ static int solo_enc_on(struct solo_enc_dev *solo_enc)
>  	if (solo_enc->bw_weight > solo_dev->enc_bw_remain)
>  		return -EBUSY;
>  	solo_enc->sequence = 0;
> -	solo_enc->motion_last_state = false;
> -	solo_enc->frames_since_last_motion = 0;
>  	solo_dev->enc_bw_remain -= solo_enc->bw_weight;
>  
>  	if (solo_enc->type == SOLO_ENC_TYPE_EXT)
> @@ -555,36 +553,12 @@ static int solo_enc_fillbuf(struct solo_enc_dev *solo_enc,
>  	}
>  
>  	if (!ret) {
> -		bool send_event = false;
> -
>  		vb->v4l2_buf.sequence = solo_enc->sequence++;
>  		vb->v4l2_buf.timestamp.tv_sec = vop_sec(vh);
>  		vb->v4l2_buf.timestamp.tv_usec = vop_usec(vh);
>  
>  		/* Check for motion flags */
> -		if (solo_is_motion_on(solo_enc)) {
> -			/* It takes a few frames for the hardware to detect
> -			 * motion. Once it does it clears the motion detection
> -			 * register and it takes again a few frames before
> -			 * motion is seen. This means in practice that when the
> -			 * motion field is 1, it will go back to 0 for the next
> -			 * frame. This leads to motion detection event being
> -			 * sent all the time, which is not what we want.
> -			 * Instead wait a few frames before deciding that the
> -			 * motion has halted. After some experimentation it
> -			 * turns out that waiting for 5 frames works well.
> -			 */
> -			if (enc_buf->motion == 0 &&
> -			    solo_enc->motion_last_state &&
> -			    solo_enc->frames_since_last_motion++ > 5)
> -				send_event = true;
> -			else if (enc_buf->motion) {
> -				solo_enc->frames_since_last_motion = 0;
> -				send_event = !solo_enc->motion_last_state;
> -			}
> -		}
> -
> -		if (send_event) {
> +		if (solo_is_motion_on(solo_enc) && enc_buf->motion) {
>  			struct v4l2_event ev = {
>  				.type = V4L2_EVENT_MOTION_DET,
>  				.u.motion_det = {
> @@ -594,8 +568,6 @@ static int solo_enc_fillbuf(struct solo_enc_dev *solo_enc,
>  				},
>  			};
>  
> -			solo_enc->motion_last_state = enc_buf->motion;
> -			solo_enc->frames_since_last_motion = 0;
>  			v4l2_event_queue(solo_enc->vfd, &ev);
>  		}
>  	}
> diff --git a/drivers/media/pci/solo6x10/solo6x10.h b/drivers/media/pci/solo6x10/solo6x10.h
> index 72017b7..dc503fd 100644
> --- a/drivers/media/pci/solo6x10/solo6x10.h
> +++ b/drivers/media/pci/solo6x10/solo6x10.h
> @@ -159,8 +159,6 @@ struct solo_enc_dev {
>  	u16			motion_thresh;
>  	bool			motion_global;
>  	bool			motion_enabled;
> -	bool			motion_last_state;
> -	u8			frames_since_last_motion;
>  	u16			width;
>  	u16			height;
>  
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/