Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Reply-To: kieran.bingham@ideasonboard.com
Subject: Re: [PATCH v3 2/9] media: vimc: Add get_frame callback
To:     Kaaira Gupta <kgupta@es.iitr.ac.in>,
        Helen Koike <helen.koike@collabora.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20200819180442.11630-1-kgupta@es.iitr.ac.in>
 <20200819180442.11630-3-kgupta@es.iitr.ac.in>
From:   Kieran Bingham <kieran.bingham@ideasonboard.com>
Autocrypt: addr=kieran.bingham@ideasonboard.com; keydata=
 mQINBFYE/WYBEACs1PwjMD9rgCu1hlIiUA1AXR4rv2v+BCLUq//vrX5S5bjzxKAryRf0uHat
 V/zwz6hiDrZuHUACDB7X8OaQcwhLaVlq6byfoBr25+hbZG7G3+5EUl9cQ7dQEdvNj6V6y/SC
 rRanWfelwQThCHckbobWiQJfK9n7rYNcPMq9B8e9F020LFH7Kj6YmO95ewJGgLm+idg1Kb3C
 potzWkXc1xmPzcQ1fvQMOfMwdS+4SNw4rY9f07Xb2K99rjMwZVDgESKIzhsDB5GY465sCsiQ
 cSAZRxqE49RTBq2+EQsbrQpIc8XiffAB8qexh5/QPzCmR4kJgCGeHIXBtgRj+nIkCJPZvZtf
 Kr2EAbc6tgg6DkAEHJb+1okosV09+0+TXywYvtEop/WUOWQ+zo+Y/OBd+8Ptgt1pDRyOBzL8
 RXa8ZqRf0Mwg75D+dKntZeJHzPRJyrlfQokngAAs4PaFt6UfS+ypMAF37T6CeDArQC41V3ko
 lPn1yMsVD0p+6i3DPvA/GPIksDC4owjnzVX9kM8Zc5Cx+XoAN0w5Eqo4t6qEVbuettxx55gq
 8K8FieAjgjMSxngo/HST8TpFeqI5nVeq0/lqtBRQKumuIqDg+Bkr4L1V/PSB6XgQcOdhtd36
 Oe9X9dXB8YSNt7VjOcO7BTmFn/Z8r92mSAfHXpb07YJWJosQOQARAQABtDBLaWVyYW4gQmlu
 Z2hhbSA8a2llcmFuLmJpbmdoYW1AaWRlYXNvbmJvYXJkLmNvbT6JAlcEEwEKAEECGwMFCwkI
 BwIGFQgJCgsCBBYCAwECHgECF4ACGQEWIQSQLdeYP70o/eNy1HqhHkZyEKRh/QUCXWTtygUJ
 CyJXZAAKCRChHkZyEKRh/f8dEACTDsbLN2nioNZMwyLuQRUAFcXNolDX48xcUXsWS2QjxaPm
 VsJx8Uy8aYkS85mdPBh0C83OovQR/OVbr8AxhGvYqBs3nQvbWuTl/+4od7DfK2VZOoKBAu5S
 QK2FYuUcikDqYcFWJ8DQnubxfE8dvzojHEkXw0sA4igINHDDFX3HJGZtLio+WpEFQtCbfTAG
 YZslasz1YZRbwEdSsmO3/kqy5eMnczlm8a21A3fKUo3g8oAZEFM+f4DUNzqIltg31OAB/kZS
 enKZQ/SWC8PmLg/ZXBrReYakxXtkP6w3FwMlzOlhGxqhIRNiAJfXJBaRhuUWzPOpEDE9q5YJ
 BmqQL2WJm1VSNNVxbXJHpaWMH1sA2R00vmvRrPXGwyIO0IPYeUYQa3gsy6k+En/aMQJd27dp
 aScf9am9PFICPY5T4ppneeJLif2lyLojo0mcHOV+uyrds9XkLpp14GfTkeKPdPMrLLTsHRfH
 fA4I4OBpRrEPiGIZB/0im98MkGY/Mu6qxeZmYLCcgD6qz4idOvfgVOrNh+aA8HzIVR+RMW8H
 QGBN9f0E3kfwxuhl3omo6V7lDw8XOdmuWZNC9zPq1UfryVHANYbLGz9KJ4Aw6M+OgBC2JpkD
 hXMdHUkC+d20dwXrwHTlrJi1YNp6rBc+xald3wsUPOZ5z8moTHUX/uPA/qhGsbkCDQRWBP1m
 ARAAzijkb+Sau4hAncr1JjOY+KyFEdUNxRy+hqTJdJfaYihxyaj0Ee0P0zEi35CbE6lgU0Uz
 tih9fiUbSV3wfsWqg1Ut3/5rTKu7kLFp15kF7eqvV4uezXRD3Qu4yjv/rMmEJbbD4cTvGCYI
 d6MDC417f7vK3hCbCVIZSp3GXxyC1LU+UQr3fFcOyCwmP9vDUR9JV0BSqHHxRDdpUXE26Dk6
 mhf0V1YkspE5St814ETXpEus2urZE5yJIUROlWPIL+hm3NEWfAP06vsQUyLvr/GtbOT79vXl
 En1aulcYyu20dRRxhkQ6iILaURcxIAVJJKPi8dsoMnS8pB0QW12AHWuirPF0g6DiuUfPmrA5
 PKe56IGlpkjc8cO51lIxHkWTpCMWigRdPDexKX+Sb+W9QWK/0JjIc4t3KBaiG8O4yRX8ml2R
 +rxfAVKM6V769P/hWoRGdgUMgYHFpHGSgEt80OKK5HeUPy2cngDUXzwrqiM5Sz6Od0qw5pCk
 NlXqI0W/who0iSVM+8+RmyY0OEkxEcci7rRLsGnM15B5PjLJjh1f2ULYkv8s4SnDwMZ/kE04
 /UqCMK/KnX8pwXEMCjz0h6qWNpGwJ0/tYIgQJZh6bqkvBrDogAvuhf60Sogw+mH8b+PBlx1L
 oeTK396wc+4c3BfiC6pNtUS5GpsPMMjYMk7kVvEAEQEAAYkCPAQYAQoAJgIbDBYhBJAt15g/
 vSj943LUeqEeRnIQpGH9BQJdizzIBQkLSKZiAAoJEKEeRnIQpGH9eYgQAJpjaWNgqNOnMTmD
 MJggbwjIotypzIXfhHNCeTkG7+qCDlSaBPclcPGYrTwCt0YWPU2TgGgJrVhYT20ierN8LUvj
 6qOPTd+Uk7NFzL65qkh80ZKNBFddx1AabQpSVQKbdcLb8OFs85kuSvFdgqZwgxA1vl4TFhNz
 PZ79NAmXLackAx3sOVFhk4WQaKRshCB7cSl+RIng5S/ThOBlwNlcKG7j7W2MC06BlTbdEkUp
 ECzuuRBv8wX4OQl+hbWbB/VKIx5HKlLu1eypen/5lNVzSqMMIYkkZcjV2SWQyUGxSwq0O/sx
 S0A8/atCHUXOboUsn54qdxrVDaK+6jIAuo8JiRWctP16KjzUM7MO0/+4zllM8EY57rXrj48j
 sbEYX0YQnzaj+jO6kJtoZsIaYR7rMMq9aUAjyiaEZpmP1qF/2sYenDx0Fg2BSlLvLvXM0vU8
 pQk3kgDu7kb/7PRYrZvBsr21EIQoIjXbZxDz/o7z95frkP71EaICttZ6k9q5oxxA5WC6sTXc
 MW8zs8avFNuA9VpXt0YupJd2ijtZy2mpZNG02fFVXhIn4G807G7+9mhuC4XG5rKlBBUXTvPU
 AfYnB4JBDLmLzBFavQfvonSfbitgXwCG3vS+9HEwAjU30Bar1PEOmIbiAoMzuKeRm2LVpmq4
 WZw01QYHU/GUV/zHJSFk
Organization: Ideas on Board
Message-ID: <80345b28-88e6-b119-5152-9f016dea2c76@ideasonboard.com>
Date:   Thu, 20 Aug 2020 16:36:56 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <20200819180442.11630-3-kgupta@es.iitr.ac.in>
Content-Type: text/plain; charset=utf-8
Content-Language: en-GB
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Kaaira,

On 19/08/2020 19:04, Kaaira Gupta wrote:
> In the process of making vimc compatible for multiple streams, we need
> to create a frame passing process such that two different entities can
> get the frame from a common entity. This isn't possible currently without
> calling process_frame twice for the common entity, as process_frames
> returns the frame which gets passed on.
> 
> So, to take care of this, add a get_frame callback to vimc device and
> use it to get the frames for an entity from previous entity instead of
> returning and passing the frames as an argument in process_frame.
> 
> Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
> ---
>  .../media/test-drivers/vimc/vimc-capture.c    | 18 +++++++++++++++---
>  drivers/media/test-drivers/vimc/vimc-common.h |  7 ++++---
>  .../media/test-drivers/vimc/vimc-debayer.c    | 19 ++++++++++++++++---
>  drivers/media/test-drivers/vimc/vimc-scaler.c | 18 +++++++++++++++---
>  drivers/media/test-drivers/vimc/vimc-sensor.c | 11 +++++++++--
>  .../media/test-drivers/vimc/vimc-streamer.c   | 10 ++++++----
>  6 files changed, 65 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c
> index c63496b17b9a..a8cbb8e4d5ba 100644
> --- a/drivers/media/test-drivers/vimc/vimc-capture.c
> +++ b/drivers/media/test-drivers/vimc/vimc-capture.c
> @@ -355,12 +355,13 @@ static void vimc_cap_unregister(struct vimc_ent_device *ved)
>  	video_unregister_device(&vcap->vdev);
>  }
>  
> -static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
> -				    const void *frame)
> +static int vimc_cap_process_frame(struct vimc_ent_device *ved)
>  {
>  	struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
>  						    ved);
>  	struct vimc_cap_buffer *vimc_buf;
> +	struct v4l2_subdev *sd;
> +	const void *frame;
>  	void *vbuf;
>  
>  	spin_lock(&vcap->qlock);
> @@ -370,7 +371,7 @@ static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
>  					    typeof(*vimc_buf), list);
>  	if (!vimc_buf) {
>  		spin_unlock(&vcap->qlock);
> -		return ERR_PTR(-EAGAIN);
> +		return -EAGAIN;
>  	}
>  
>  	/* Remove this entry from the list */
> @@ -385,12 +386,22 @@ static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
>  
>  	vbuf = vb2_plane_vaddr(&vimc_buf->vb2.vb2_buf, 0);
>  
> +	sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> +	ved = v4l2_get_subdevdata(sd);
> +	frame = ved->get_frame(ved);

Hrm, this code block is used in several places throughout this patch,
and it aliases the function parameter ved to a new device which isn't
nice. Not a problem as long as it's not used for the original VED after
of course.

But I wonder if we should instead add a helper into vimc-common.c:

struct vimc_ent_device *vimc_get_source_ved(struct vimc_ent_device *ved)
{
	struct media_entity *ent;
	struct v4l2_subdev *sd;

	ent = vimc_get_source_entity(ved->ent);
	if (!ent)
		return NULL;

	sd = media_entity_to_v4l2_subdev(ent);

	return v4l2_get_subdevdata(sd);
}

It might not be necessary though, just an idea. If you like it, it can
be a patch on it's own after the vimc_get_source_entity() moving patch.


But it does show that vimc_get_source_entity() can return NULL which
might have to be checked... though perhaps we 'know' it will always be
valid ...

Also, following the links for each entity, for each frame sounds like
quite a lot of work. I wonder if the active source entity should be
cached in each VED ...

That could be done on top anyway...

Overall, this looks like it will work, so with comments addressed how
you wish,

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>


> +
>  	memcpy(vbuf, frame, vcap->format.sizeimage);
>  
>  	/* Set it as ready */
>  	vb2_set_plane_payload(&vimc_buf->vb2.vb2_buf, 0,
>  			      vcap->format.sizeimage);
>  	vb2_buffer_done(&vimc_buf->vb2.vb2_buf, VB2_BUF_STATE_DONE);
> +
> +	return 0;
> +}
> +
> +static void *vimc_cap_get_frame(struct vimc_ent_device *ved)
> +{
>  	return NULL;
>  }
>  
> @@ -455,6 +466,7 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
>  	vcap->ved.ent = &vcap->vdev.entity;
>  	vcap->ved.process_frame = vimc_cap_process_frame;
>  	vcap->ved.vdev_get_format = vimc_cap_get_format;
> +	vcap->ved.get_frame = vimc_cap_get_frame;
>  	vcap->ved.dev = vimc->mdev.dev;
>  
>  	/* Initialize the video_device struct */
> diff --git a/drivers/media/test-drivers/vimc/vimc-common.h b/drivers/media/test-drivers/vimc/vimc-common.h
> index 4c580d854007..287d66edff49 100644
> --- a/drivers/media/test-drivers/vimc/vimc-common.h
> +++ b/drivers/media/test-drivers/vimc/vimc-common.h
> @@ -85,7 +85,8 @@ struct vimc_pix_map {
>   *
>   * @dev:		a pointer of the device struct of the driver
>   * @ent:		the pointer to struct media_entity for the node
> - * @process_frame:	callback send a frame to that node
> + * @get_frame:		callback that sends a frame processed by the entity

s/sends a/obtains the/


> + * @process_frame:	callback that processes a frame
>   * @vdev_get_format:	callback that returns the current format a pad, used
>   *			only when is_media_entity_v4l2_video_device(ent) returns
>   *			true
> @@ -101,8 +102,8 @@ struct vimc_pix_map {
>  struct vimc_ent_device {
>  	struct device *dev;
>  	struct media_entity *ent;
> -	void * (*process_frame)(struct vimc_ent_device *ved,
> -				const void *frame);
> +	void * (*get_frame)(struct vimc_ent_device *ved);
> +	int (*process_frame)(struct vimc_ent_device *ved);
>  	void (*vdev_get_format)(struct vimc_ent_device *ved,
>  			      struct v4l2_pix_format *fmt);
>  };
> diff --git a/drivers/media/test-drivers/vimc/vimc-debayer.c b/drivers/media/test-drivers/vimc/vimc-debayer.c
> index c3f6fef34f68..f61e6e8899ac 100644
> --- a/drivers/media/test-drivers/vimc/vimc-debayer.c
> +++ b/drivers/media/test-drivers/vimc/vimc-debayer.c
> @@ -491,17 +491,22 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
>  	}
>  }
>  
> -static void *vimc_deb_process_frame(struct vimc_ent_device *ved,
> -				    const void *sink_frame)
> +static int vimc_deb_process_frame(struct vimc_ent_device *ved)
>  {
>  	struct vimc_deb_device *vdeb = container_of(ved, struct vimc_deb_device,
>  						    ved);
>  	unsigned int rgb[3];
>  	unsigned int i, j;
> +	struct v4l2_subdev *sd;
> +	const void *sink_frame;
>  
>  	/* If the stream in this node is not active, just return */
>  	if (!vdeb->src_frame)
> -		return ERR_PTR(-EINVAL);
> +		return -EINVAL;
> +
> +	sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> +	ved = v4l2_get_subdevdata(sd);
> +	sink_frame = ved->get_frame(ved);
>  
>  	for (i = 0; i < vdeb->sink_fmt.height; i++)
>  		for (j = 0; j < vdeb->sink_fmt.width; j++) {
> @@ -509,6 +514,13 @@ static void *vimc_deb_process_frame(struct vimc_ent_device *ved,
>  			vdeb->set_rgb_src(vdeb, i, j, rgb);
>  		}
>  
> +	return 0;
> +}
> +
> +static void *vimc_deb_get_frame(struct vimc_ent_device *ved)
> +{
> +	struct vimc_deb_device *vdeb = container_of(ved, struct vimc_deb_device,
> +						    ved);
>  	return vdeb->src_frame;
>  }
>  
> @@ -593,6 +605,7 @@ static struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
>  		goto err_free_hdl;
>  
>  	vdeb->ved.process_frame = vimc_deb_process_frame;
> +	vdeb->ved.get_frame = vimc_deb_get_frame;
>  	vdeb->ved.dev = vimc->mdev.dev;
>  	vdeb->mean_win_size = vimc_deb_ctrl_mean_win_size.def;
>  
> diff --git a/drivers/media/test-drivers/vimc/vimc-scaler.c b/drivers/media/test-drivers/vimc/vimc-scaler.c
> index 121fa7d62a2e..347f9cd4a168 100644
> --- a/drivers/media/test-drivers/vimc/vimc-scaler.c
> +++ b/drivers/media/test-drivers/vimc/vimc-scaler.c
> @@ -455,18 +455,29 @@ static void vimc_sca_fill_src_frame(const struct vimc_sca_device *const vsca,
>  			vimc_sca_scale_pix(vsca, i, j, sink_frame);
>  }
>  
> -static void *vimc_sca_process_frame(struct vimc_ent_device *ved,
> -				    const void *sink_frame)
> +static int vimc_sca_process_frame(struct vimc_ent_device *ved)
>  {
>  	struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
>  						    ved);
> +	const void *sink_frame;
> +	struct v4l2_subdev *sd;
>  
>  	/* If the stream in this node is not active, just return */
>  	if (!vsca->src_frame)
> -		return ERR_PTR(-EINVAL);
> +		return -EINVAL;
>  
> +	sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> +	ved = v4l2_get_subdevdata(sd);
> +	sink_frame = ved->get_frame(ved);
>  	vimc_sca_fill_src_frame(vsca, sink_frame);
>  
> +	return 0;
> +};
> +
> +static void *vimc_sca_get_frame(struct vimc_ent_device *ved)
> +{
> +	struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
> +						    ved);
>  	return vsca->src_frame;
>  };
>  
> @@ -505,6 +516,7 @@ static struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc,
>  	}
>  
>  	vsca->ved.process_frame = vimc_sca_process_frame;
> +	vsca->ved.get_frame = vimc_sca_get_frame;
>  	vsca->ved.dev = vimc->mdev.dev;
>  
>  	/* Initialize the frame format */
> diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
> index ba5db5a150b4..32a2c39de2cd 100644
> --- a/drivers/media/test-drivers/vimc/vimc-sensor.c
> +++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
> @@ -190,8 +190,7 @@ static const struct v4l2_subdev_pad_ops vimc_sen_pad_ops = {
>  	.set_fmt		= vimc_sen_set_fmt,
>  };
>  
> -static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
> -				    const void *sink_frame)
> +static int vimc_sen_process_frame(struct vimc_ent_device *ved)
>  {
>  	struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
>  						    ved);
> @@ -238,6 +237,13 @@ static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
>  		break;
>  	}
>  
> +	return 0;
> +}
> +
> +static void *vimc_sen_get_frame(struct vimc_ent_device *ved)
> +{
> +	struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
> +						    ved);
>  	return vsen->frame;
>  }
>  
> @@ -429,6 +435,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
>  		goto err_free_tpg;
>  
>  	vsen->ved.process_frame = vimc_sen_process_frame;
> +	vsen->ved.get_frame = vimc_sen_get_frame;
>  	vsen->ved.dev = vimc->mdev.dev;
>  
>  	/* Initialize the frame format */
> diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
> index 4f8384246042..c1644d69686d 100644
> --- a/drivers/media/test-drivers/vimc/vimc-streamer.c
> +++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
> @@ -125,7 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>  static int vimc_streamer_thread(void *data)
>  {
>  	struct vimc_stream *stream = data;
> -	u8 *frame = NULL;
> +	struct vimc_ent_device *ved;
> +	int ret;
>  	int i;
>  
>  	set_freezable();
> @@ -136,9 +137,10 @@ static int vimc_streamer_thread(void *data)
>  			break;
>  
>  		for (i = stream->pipe_size - 1; i >= 0; i--) {
> -			frame = stream->ved_pipeline[i]->process_frame(
> -					stream->ved_pipeline[i], frame);
> -			if (!frame || IS_ERR(frame))
> +			ved = stream->ved_pipeline[i];
> +			ret = ved->process_frame(ved);
> +
> +			if (ret)
>  				break;
>  		}
>  		//wait for 60hz
> 

-- 
Regards
--
Kieran