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* [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable}
@ 2020-05-22  7:55 Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 1/5] media: mc-entity.c: add media_graph_walk_next_stream() Dafna Hirschfeld
                   ` (5 more replies)
  0 siblings, 6 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

Hi,
This is v4 of the patchset that was sent by Helen Koike.

Media drivers need to iterate through the pipeline and call .s_stream()
callbacks in the subdevices.

Instead of repeating code, add helpers for this.

These helpers will go walk through the pipeline only visiting entities
that participates in the stream, i.e. it follows links from sink to source
(and not the opposite).
For example, in a topology like this https://bit.ly/3b2MxjI
calling v4l2_pipeline_stream_enable() from rkisp1_mainpath won't call
.s_stream(true) for rkisp1_resizer_selfpath.

stream_count variable was added in v4l2_subdevice to handle nested calls
to the helpers.
This is useful when the driver allows streaming from more then one
capture device sharing subdevices.

This patchset was tested on rkisp1 and vimc drivers.

Other cleanup might be possible (but I won't add in this patchset as I
don't have the hw to test):
	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/qcom/camss/camss-video.c#n430
	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/omap3isp/isp.c#n697
	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/stm32/stm32-dcmi.c#n680
	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/xilinx/xilinx-dma.c#n97

Testing:
--------

SEN_DEV=/dev/v4l-subdev3
ISP_DEV=/dev/v4l-subdev0
RSZ_SP_DEV=/dev/v4l-subdev2
RSZ_MP_DEV=/dev/v4l-subdev1
CAP_SP_DEV=/dev/video1
CAP_MP_DEV=/dev/video0

WIDTH=1920
HEIGHT=1080
RAW_CODE=SRGGB10_1X10
YUV_CODE=YUYV8_2X8

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $SEN_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $ISP_DEV
v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV

v4l2-ctl --set-subdev-selection pad=2,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV
v4l2-ctl --set-subdev-fmt pad=2,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $ISP_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV
v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV

v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_SP_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV
v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV

v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_MP_DEV

v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_SP_DEV
v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_MP_DEV

sleep 1

v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_SP_DEV --stream-to=/tmp/test_sp.raw &
v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_MP_DEV --stream-to=/tmp/test_mp.raw &

wait
echo "Completed"


Changes in v4:
==============
patch 1: fix coding style issues

patch 2:
- in function v4l2_pipeline_subdevs_get, use a local media_graph to walk on the topology so a lock is not needed
and also the pipe parameter is not needed.
- adding a function v4l2_subdevs_stream_disable to avoid code duplication
- change v4l2_pipeline_stream_disable to return an error code if failed
- don't add a new field to subdevice "stream_counter" when calling s_stream, since this counter is updated only in
the helper functions, and might be confusing that it is generally not an indication of the number of calls to s_stream.
Also, except of rkisp1, and vimc, it seems that the other drivers that might use the new helpers don't use a counter.

new added - patch 3: the call to media_pipeline_start should be called before calling s_stream on the subdevices in order
to validate the links and prevents them from changing, this patch fixes it.

patch 4: (use the helpers in rkisp1). The helpers now don't have a counter for the number of calls to s_stream, so rkisp1
should check if the other capture is streaming and in that case call s_stream only for its resizer.

patch 5: - (use the helpers in vimc)
- test the return value of v4l2_pipeline_stream_disable
- the call to the helerps now doesn't need the pipe parameter.

Overview of patches in V3:
--------------------------

Patch 1/5 adds a new iterator function in media-controller to follow links from sink to
source only.

Patch 2/5 adds the helpers in v4l2-common.c,

Patch 3/5 calles media_pipeline_start before calling s_stream on the subdevices

Patch 4/5 cleanup rkisp1 driver to use the helpers.

Patch 5/5 cleanup vimc driver to use the helpers.

Changes in V3:
====================
Following up Niklas' comments in V2 https://patchwork.kernel.org/patch/11473681/#23270823

* I removed the limitation in topologies with entities with multiple enabled
links to its sink pads in the topology.
Now it enables all subdevs in the pipeline that have an enabled link going
from sink to source while walking from the video device, so it can be
also useful for rcar-vin driver.

To implement this, I added back in the series the patch from v1:
    "media: mc-entity.c: add media_graph_walk_next_stream()"

* "size" was renamed to "max_size" in function v4l2_pipeline_subdevs_get()
to reflect the maximum number of elements that can fit in the subdevs array,
with proper documentation.

* v4l2_pipeline_subdevs_get() returns a negative number for error, instead
of returning 0 and printing a warning.

* I also add if defined(CONFIG_MEDIA_CONTROLLER) around helpers to avoid
compiling errors.

Overview of patches in V3:
--------------------------

Patch 1/4 adds a new iterator function in media-controller to follow links from sink to
source only.

Patch 2/4 adds the helpers in v4l2-common.c, allowing nested calls by
adding stream_count in the subdevice struct.

Patch 3/4 cleanup rkisp1 driver to use the helpers.

Patch 4/4 cleanup vimc driver to use the helpers.

Changes in V2:
====================
The first version was calling the s_stream() callbacks from sensor to
capture.

This was generating errors in the Scarlet Chromebook, when the sensor
was being enabled before the ISP.

It make sense to enable subdevices from capture to sensor instead (which
is what most drivers do already).

This v2 drops the changes from mc-entity.c, and re-implement helpers in
v4l2-common.c

Overview of patches in V2:
--------------------------

Path 1/3 adds the helpers in v4l2-common.c, allowing nested calls by
adding stream_count in the subdevice struct.

Patch 2/3 cleanup rkisp1 driver to use the helpers.

Patch 3/3 cleanup vimc driver to use the helpers.

Dafna Hirschfeld (1):
  media: staging: rkisp1: validate links before powering and streaming

Helen Koike (4):
  media: mc-entity.c: add media_graph_walk_next_stream()
  media: v4l2-common: add helper functions to call s_stream() callbacks
  media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable}
    helpers
  media: vimc: use v4l2_pipeline_stream_{enable,disable} helpers

 drivers/media/mc/mc-entity.c                  |  34 ++++-
 .../media/test-drivers/vimc/vimc-capture.c    |  31 +++--
 .../media/test-drivers/vimc/vimc-streamer.c   |  49 +------
 drivers/media/v4l2-core/v4l2-common.c         |  99 ++++++++++++++
 drivers/staging/media/rkisp1/rkisp1-capture.c | 125 ++++++------------
 include/media/media-entity.h                  |  15 +++
 include/media/v4l2-common.h                   |  39 ++++++
 7 files changed, 253 insertions(+), 139 deletions(-)

-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH v4 1/5] media: mc-entity.c: add media_graph_walk_next_stream()
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
@ 2020-05-22  7:55 ` Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks Dafna Hirschfeld
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

From: Helen Koike <helen.koike@collabora.com>

Add media_graph_walk_next_stream() function to follow links only from
sink to source (not the opposite) to allow iteration only through the
entities participating in a given stream.

This is useful to allow calling .s_stream() callback only in the
subdevices that requires to be enabled/disabled, and avoid calling this
callback when not required.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
[Dafna: fixing coding style issues]
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/media/mc/mc-entity.c | 34 +++++++++++++++++++++++++++++++---
 include/media/media-entity.h | 15 +++++++++++++++
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 12b45e669bcc..555f9dd9f7f2 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -228,6 +228,11 @@ EXPORT_SYMBOL_GPL(media_entity_pads_init);
  * Graph traversal
  */
 
+enum media_graph_walk_type {
+	MEDIA_GRAPH_WALK_CONNECTED_NODES,
+	MEDIA_GRAPH_WALK_STREAM_NODES,
+};
+
 static struct media_entity *
 media_entity_other(struct media_entity *entity, struct media_link *link)
 {
@@ -305,7 +310,8 @@ void media_graph_walk_start(struct media_graph *graph,
 }
 EXPORT_SYMBOL_GPL(media_graph_walk_start);
 
-static void media_graph_walk_iter(struct media_graph *graph)
+static void media_graph_walk_iter(struct media_graph *graph,
+				  enum media_graph_walk_type type)
 {
 	struct media_entity *entity = stack_top(graph);
 	struct media_link *link;
@@ -326,6 +332,15 @@ static void media_graph_walk_iter(struct media_graph *graph)
 	/* Get the entity in the other end of the link . */
 	next = media_entity_other(entity, link);
 
+	if (type == MEDIA_GRAPH_WALK_STREAM_NODES &&
+	    next == link->sink->entity) {
+		link_top(graph) = link_top(graph)->next;
+		dev_dbg(entity->graph_obj.mdev->dev,
+			"walk: skipping '%s' (outside of the stream path)\n",
+			link->sink->entity->name);
+		return;
+	}
+
 	/* Has the entity already been visited? */
 	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
 		link_top(graph) = link_top(graph)->next;
@@ -342,7 +357,9 @@ static void media_graph_walk_iter(struct media_graph *graph)
 		next->name);
 }
 
-struct media_entity *media_graph_walk_next(struct media_graph *graph)
+static struct media_entity *
+__media_graph_walk_next(struct media_graph *graph,
+			enum media_graph_walk_type type)
 {
 	struct media_entity *entity;
 
@@ -355,7 +372,7 @@ struct media_entity *media_graph_walk_next(struct media_graph *graph)
 	 * found.
 	 */
 	while (link_top(graph) != &stack_top(graph)->links)
-		media_graph_walk_iter(graph);
+		media_graph_walk_iter(graph, type);
 
 	entity = stack_pop(graph);
 	dev_dbg(entity->graph_obj.mdev->dev,
@@ -363,8 +380,19 @@ struct media_entity *media_graph_walk_next(struct media_graph *graph)
 
 	return entity;
 }
+
+struct media_entity *media_graph_walk_next(struct media_graph *graph)
+{
+	return __media_graph_walk_next(graph, MEDIA_GRAPH_WALK_CONNECTED_NODES);
+}
 EXPORT_SYMBOL_GPL(media_graph_walk_next);
 
+struct media_entity *media_graph_walk_next_stream(struct media_graph *graph)
+{
+	return __media_graph_walk_next(graph, MEDIA_GRAPH_WALK_STREAM_NODES);
+}
+EXPORT_SYMBOL_GPL(media_graph_walk_next_stream);
+
 int media_entity_get_fwnode_pad(struct media_entity *entity,
 				struct fwnode_handle *fwnode,
 				unsigned long direction_flags)
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index cde80ad029b7..9035a36e9442 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -928,6 +928,21 @@ void media_graph_walk_start(struct media_graph *graph,
  */
 struct media_entity *media_graph_walk_next(struct media_graph *graph);
 
+/**
+ * media_graph_walk_next_stream - Get the next entity in the graph
+ * @graph: Media graph structure
+ *
+ * Perform a depth-first traversal of the given media entities graph only
+ * following links from sink to source (and not the opposite).
+ *
+ * The graph structure must have been previously initialized with a call to
+ * media_graph_walk_start().
+ *
+ * Return: returns the next entity in the graph in the stream path
+ * or %NULL if the whole stream path have been traversed.
+ */
+struct media_entity *media_graph_walk_next_stream(struct media_graph *graph);
+
 /**
  * media_pipeline_start - Mark a pipeline as streaming
  * @entity: Starting entity
-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 1/5] media: mc-entity.c: add media_graph_walk_next_stream() Dafna Hirschfeld
@ 2020-05-22  7:55 ` Dafna Hirschfeld
  2020-05-25  9:23   ` Sakari Ailus
  2020-05-22  7:55 ` [PATCH v4 3/5] media: staging: rkisp1: validate links before powering and streaming Dafna Hirschfeld
                   ` (3 subsequent siblings)
  5 siblings, 1 reply; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

From: Helen Koike <helen.koike@collabora.com>

Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
through the subdevices in a given stream (i.e following links from sink
to source) and call .s_stream() callback.

If .s_stream(true) fails, call .s_stream(false) in the reverse order.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
 include/media/v4l2-common.h           | 39 +++++++++++
 2 files changed, 138 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 9e8eb45a5b03..734db2bf5ca9 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+
+/*
+ * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline
+ * @subdevs: the array to be filled.
+ * @max_size: max number of elements that can fit in subdevs array.
+ *
+ * Walk from a video node, following links from sink to source and fill the
+ * array with subdevices in the path.
+ * The walker performs a depth-first traversal, which means that, in a topology
+ * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array.
+ *
+ * Return the number of subdevices filled in the array.
+ */
+static int v4l2_pipeline_subdevs_get(struct video_device *vdev,
+				     struct v4l2_subdev **subdevs,
+				     unsigned int max_size)
+{
+	struct media_entity *entity = &vdev->entity;
+	struct media_device *mdev = entity->graph_obj.mdev;
+	struct media_graph graph;
+	int idx = 0;
+	int ret;
+
+	ret = media_graph_walk_init(&graph, mdev);
+	if (ret)
+		return ret;
+
+	media_graph_walk_start(&graph, entity);
+
+	while ((entity = media_graph_walk_next_stream(&graph))) {
+		if (!is_media_entity_v4l2_subdev(entity))
+			continue;
+		if (WARN_ON(idx >= max_size))
+			return -EINVAL;
+		subdevs[idx++] = media_entity_to_v4l2_subdev(entity);
+	}
+
+	media_graph_walk_cleanup(&graph);
+
+	return idx;
+}
+
+static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++) {
+		struct v4l2_subdev *sd = subdevs[i];
+
+		dev_dbg(sd->dev,
+			"disabling stream for '%s'\n", sd->entity.name);
+		v4l2_subdev_call(sd, video, s_stream, false);
+	}
+}
+
+__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev)
+{
+	struct media_device *mdev = vdev->entity.graph_obj.mdev;
+	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
+	struct v4l2_subdev *sd;
+	int i, size, ret;
+
+	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
+	if (size <= 0)
+		return size;
+
+	/* Call s_stream() in reverse order to enable sensors last */
+	for (i = size - 1; i >= 0; i--) {
+		sd = subdevs[i];
+		dev_dbg(mdev->dev,
+			"enabling stream for '%s'\n", sd->entity.name);
+		ret = v4l2_subdev_call(sd, video, s_stream, true);
+		if (ret && ret != -ENOIOCTLCMD) {
+			v4l2_subdevs_stream_disable(subdevs + i + 1,
+						    size - i - 1);
+			return ret;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
+
+int v4l2_pipeline_stream_disable(struct video_device *vdev)
+{
+	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
+	int size;
+
+	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
+	if (size < 0)
+		return size;
+
+	v4l2_subdevs_stream_disable(subdevs, size);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
+
+#endif /* CONFIG_MEDIA_CONTROLLER */
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 150ee16ebd81..a278bcf3c5bc 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
 	buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
 }
 
+#if defined(CONFIG_MEDIA_CONTROLLER)
+
+/**
+ * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
+ * @vdev: Starting video device.
+ *
+ * Call .s_stream(true) callback in all the subdevices participating in the
+ * stream, i.e. following links from sink to source.
+ *
+ * .s_stream(true) is also called from sink to source, i.e. in a topology
+ * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first.
+ *
+ * Calls to this function can be nested, in which case the same number of
+ * v4l2_pipeline_stream_disable() calls will be required to disable streaming
+ * through subdevices in the pipeline.
+ * The  pipeline pointer must be identical for all nested calls to
+ * v4l2_pipeline_stream_enable().
+ */
+__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev);
+
+/**
+ * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream
+ * @vdev: Starting video device.
+ *
+ * Call .s_stream(false) callback in all the subdevices participating in the
+ * stream, i.e. following links from sink to source.
+ *
+ * s_stream(false) is called in a reverse order from
+ * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev,
+ * .s_stream(false) of sd1 is called first.
+ *
+ * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same
+ * number of calls to this function are required to disable streaming through
+ * subdevices in the pipeline.
+ */
+int v4l2_pipeline_stream_disable(struct video_device *vdev);
+
+#endif /* CONFIG_MEDIA_CONTROLLER */
+
 #endif /* V4L2_COMMON_H_ */
-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH v4 3/5] media: staging: rkisp1: validate links before powering and streaming
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 1/5] media: mc-entity.c: add media_graph_walk_next_stream() Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks Dafna Hirschfeld
@ 2020-05-22  7:55 ` Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 4/5] media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable} helpers Dafna Hirschfeld
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

In function rkisp1_vb2_start_streaming, the call to
media_pipeline_start should be the first thing in order
to validate the links and prevents their state from being modified
before power up and streaming.

Adjust stop streaming to the same logic, call media_pipeline_stop
after we disable streaming on the entities in the topology.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/staging/media/rkisp1/rkisp1-capture.c | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
index f69235f82c45..008c070373f8 100644
--- a/drivers/staging/media/rkisp1/rkisp1-capture.c
+++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
@@ -898,7 +898,6 @@ static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
 	mutex_lock(&cap->rkisp1->stream_lock);
 
 	rkisp1_stream_stop(cap);
-	media_pipeline_stop(&node->vdev.entity);
 	ret = rkisp1_pipeline_sink_walk(&node->vdev.entity, NULL,
 					rkisp1_pipeline_disable_cb);
 	if (ret)
@@ -914,6 +913,8 @@ static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
 
 	rkisp1_dummy_buf_destroy(cap);
 
+	media_pipeline_stop(&node->vdev.entity);
+
 	mutex_unlock(&cap->rkisp1->stream_lock);
 }
 
@@ -961,9 +962,15 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
 
 	mutex_lock(&cap->rkisp1->stream_lock);
 
+	ret = media_pipeline_start(entity, &cap->rkisp1->pipe);
+	if (ret) {
+		dev_err(cap->rkisp1->dev, "start pipeline failed %d\n", ret);
+		goto err_ret_buffers;
+	}
+
 	ret = rkisp1_dummy_buf_create(cap);
 	if (ret)
-		goto err_ret_buffers;
+		goto err_pipeline_stop;
 
 	ret = pm_runtime_get_sync(cap->rkisp1->dev);
 	if (ret < 0) {
@@ -984,18 +991,10 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
 	if (ret)
 		goto err_stop_stream;
 
-	ret = media_pipeline_start(entity, &cap->rkisp1->pipe);
-	if (ret) {
-		dev_err(cap->rkisp1->dev, "start pipeline failed %d\n", ret);
-		goto err_pipe_disable;
-	}
-
 	mutex_unlock(&cap->rkisp1->stream_lock);
 
 	return 0;
 
-err_pipe_disable:
-	rkisp1_pipeline_sink_walk(entity, NULL, rkisp1_pipeline_disable_cb);
 err_stop_stream:
 	rkisp1_stream_stop(cap);
 	v4l2_pipeline_pm_put(entity);
@@ -1003,6 +1002,8 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
 	pm_runtime_put(cap->rkisp1->dev);
 err_destroy_dummy:
 	rkisp1_dummy_buf_destroy(cap);
+err_pipeline_stop:
+	media_pipeline_stop(entity);
 err_ret_buffers:
 	rkisp1_return_all_buffers(cap, VB2_BUF_STATE_QUEUED);
 	mutex_unlock(&cap->rkisp1->stream_lock);
-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH v4 4/5] media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable} helpers
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
                   ` (2 preceding siblings ...)
  2020-05-22  7:55 ` [PATCH v4 3/5] media: staging: rkisp1: validate links before powering and streaming Dafna Hirschfeld
@ 2020-05-22  7:55 ` Dafna Hirschfeld
  2020-05-22  7:55 ` [PATCH v4 5/5] media: vimc: " Dafna Hirschfeld
  2020-05-22  9:06 ` [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Helen Koike
  5 siblings, 0 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

From: Helen Koike <helen.koike@collabora.com>

Use v4l2_pipeline_stream_{enable,disable} to call .s_stream()
subdevice callbacks through the pipeline.
Those helpers are called only if the other capture is not streaming.

If the other capture is streaming then he already did that for us
so we call s_stream only on the resizer that is connected to the
capture node.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/staging/media/rkisp1/rkisp1-capture.c | 104 ++++++------------
 1 file changed, 32 insertions(+), 72 deletions(-)

diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
index 008c070373f8..d53a8549da77 100644
--- a/drivers/staging/media/rkisp1/rkisp1-capture.c
+++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
@@ -806,71 +806,6 @@ static void rkisp1_return_all_buffers(struct rkisp1_capture *cap,
 	spin_unlock_irqrestore(&cap->buf.lock, flags);
 }
 
-/*
- * rkisp1_pipeline_sink_walk - Walk through the pipeline and call cb
- * @from: entity at which to start pipeline walk
- * @until: entity at which to stop pipeline walk
- *
- * Walk the entities chain starting at the pipeline video node and stop
- * all subdevices in the chain.
- *
- * If the until argument isn't NULL, stop the pipeline walk when reaching the
- * until entity. This is used to disable a partially started pipeline due to a
- * subdev start error.
- */
-static int rkisp1_pipeline_sink_walk(struct media_entity *from,
-				     struct media_entity *until,
-				     int (*cb)(struct media_entity *from,
-					       struct media_entity *curr))
-{
-	struct media_entity *entity = from;
-	struct media_pad *pad;
-	unsigned int i;
-	int ret;
-
-	while (1) {
-		pad = NULL;
-		/* Find remote source pad */
-		for (i = 0; i < entity->num_pads; i++) {
-			struct media_pad *spad = &entity->pads[i];
-
-			if (!(spad->flags & MEDIA_PAD_FL_SINK))
-				continue;
-			pad = media_entity_remote_pad(spad);
-			if (pad && is_media_entity_v4l2_subdev(pad->entity))
-				break;
-		}
-		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
-			break;
-
-		entity = pad->entity;
-		if (entity == until)
-			break;
-
-		ret = cb(from, entity);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-static int rkisp1_pipeline_disable_cb(struct media_entity *from,
-				      struct media_entity *curr)
-{
-	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
-
-	return v4l2_subdev_call(sd, video, s_stream, false);
-}
-
-static int rkisp1_pipeline_enable_cb(struct media_entity *from,
-				     struct media_entity *curr)
-{
-	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
-
-	return v4l2_subdev_call(sd, video, s_stream, true);
-}
-
 static void rkisp1_stream_stop(struct rkisp1_capture *cap)
 {
 	int ret;
@@ -888,6 +823,36 @@ static void rkisp1_stream_stop(struct rkisp1_capture *cap)
 	}
 }
 
+static int rkisp1_s_stream_subdev(struct rkisp1_capture *cap, int enable)
+{
+	struct rkisp1_device *rkisp1 = cap->rkisp1;
+	struct rkisp1_capture *other = &rkisp1->capture_devs[cap->id ^ 1];
+	int ret;
+
+	/*
+	 * if the other capture is already streaming then we only need to
+	 * call s_stream of our reszier
+	 */
+	if (other->is_streaming) {
+		struct v4l2_subdev *rsz_sd  = &rkisp1->resizer_devs[cap->id].sd;
+
+		ret = v4l2_subdev_call(rsz_sd, video, s_stream, enable);
+		if (ret && ret != -ENOIOCTLCMD)
+			dev_err(rkisp1->dev,
+				"stream %s resizer '%s' failed (%d)\n",
+				enable ? "on" : "off", rsz_sd->name, ret);
+	} else {
+		if (enable)
+			ret = v4l2_pipeline_stream_enable(&cap->vnode.vdev);
+		else
+			ret = v4l2_pipeline_stream_disable(&cap->vnode.vdev);
+		if (ret < 0)
+			dev_err(rkisp1->dev, "stream subdevs %s failed %d\n",
+				enable ? "on" : "off", ret);
+	}
+	return ret;
+}
+
 static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
 {
 	struct rkisp1_capture *cap = queue->drv_priv;
@@ -898,11 +863,7 @@ static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
 	mutex_lock(&cap->rkisp1->stream_lock);
 
 	rkisp1_stream_stop(cap);
-	ret = rkisp1_pipeline_sink_walk(&node->vdev.entity, NULL,
-					rkisp1_pipeline_disable_cb);
-	if (ret)
-		dev_err(rkisp1->dev,
-			"pipeline stream-off failed error:%d\n", ret);
+	rkisp1_s_stream_subdev(cap, 0);
 
 	rkisp1_return_all_buffers(cap, VB2_BUF_STATE_ERROR);
 
@@ -986,8 +947,7 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
 	rkisp1_stream_start(cap);
 
 	/* start sub-devices */
-	ret = rkisp1_pipeline_sink_walk(entity, NULL,
-					rkisp1_pipeline_enable_cb);
+	ret = rkisp1_s_stream_subdev(cap, 1);
 	if (ret)
 		goto err_stop_stream;
 
-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH v4 5/5] media: vimc: use v4l2_pipeline_stream_{enable,disable} helpers
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
                   ` (3 preceding siblings ...)
  2020-05-22  7:55 ` [PATCH v4 4/5] media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable} helpers Dafna Hirschfeld
@ 2020-05-22  7:55 ` Dafna Hirschfeld
  2020-05-22  9:06 ` [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Helen Koike
  5 siblings, 0 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-22  7:55 UTC (permalink / raw)
  To: linux-media, laurent.pinchart
  Cc: dafna.hirschfeld, helen.koike, ezequiel, hverkuil, kernel,
	dafna3, sakari.ailus, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

From: Helen Koike <helen.koike@collabora.com>

Use v4l2_pipeline_stream_{enable,disable} to call .s_stream() subdevice
callbacks through the pipeline.

Tested streaming works with:

media-ctl -d /dev/media0 -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Scaler":0[fmt:RGB888_1X24/640x480]'
media-ctl -d /dev/media0 -V '"Scaler":0[crop:(100,50)/400x150]'
media-ctl -d /dev/media0 -V '"Scaler":1[fmt:RGB888_1X24/1920x1440]'
v4l2-ctl -d /dev/video2 -v width=1200,height=450
v4l2-ctl -d /dev/video0 -v pixelformat=BA81
v4l2-ctl -d /dev/video1 -v pixelformat=BA81
v4l2-ctl --stream-mmap --stream-count=10 -d /dev/video2 --stream-to=/tmp/test.raw

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 .../media/test-drivers/vimc/vimc-capture.c    | 31 ++++++++----
 .../media/test-drivers/vimc/vimc-streamer.c   | 49 ++-----------------
 2 files changed, 26 insertions(+), 54 deletions(-)

diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c
index c63496b17b9a..36ba664db092 100644
--- a/drivers/media/test-drivers/vimc/vimc-capture.c
+++ b/drivers/media/test-drivers/vimc/vimc-capture.c
@@ -245,21 +245,27 @@ static int vimc_cap_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 	vcap->sequence = 0;
 
-	/* Start the media pipeline */
 	ret = media_pipeline_start(entity, &vcap->stream.pipe);
-	if (ret) {
-		vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
-		return ret;
-	}
+	if (ret)
+		goto err_return_all_buffers;
+
+	ret = v4l2_pipeline_stream_enable(&vcap->vdev);
+	if (ret)
+		goto err_stop_media_pipe;
 
 	ret = vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 1);
-	if (ret) {
-		media_pipeline_stop(entity);
-		vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
-		return ret;
-	}
+	if (ret)
+		goto err_stop_stream;
 
 	return 0;
+
+err_stop_stream:
+	v4l2_pipeline_stream_disable(&vcap->vdev);
+err_stop_media_pipe:
+	media_pipeline_stop(entity);
+err_return_all_buffers:
+	vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
+	return ret;
 }
 
 /*
@@ -269,9 +275,14 @@ static int vimc_cap_start_streaming(struct vb2_queue *vq, unsigned int count)
 static void vimc_cap_stop_streaming(struct vb2_queue *vq)
 {
 	struct vimc_cap_device *vcap = vb2_get_drv_priv(vq);
+	int ret;
 
 	vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 0);
 
+	ret = v4l2_pipeline_stream_disable(&vcap->vdev);
+	if (ret)
+		dev_err(vcap->ved.dev, "stream disable failed: %d\n", ret);
+
 	/* Stop the media pipeline */
 	media_pipeline_stop(&vcap->vdev.entity);
 
diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
index 65feb3c596db..c0085f4695c2 100644
--- a/drivers/media/test-drivers/vimc/vimc-streamer.c
+++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
@@ -36,33 +36,6 @@ static struct media_entity *vimc_get_source_entity(struct media_entity *ent)
 	return NULL;
 }
 
-/**
- * vimc_streamer_pipeline_terminate - Disable stream in all ved in stream
- *
- * @stream: the pointer to the stream structure with the pipeline to be
- *	    disabled.
- *
- * Calls s_stream to disable the stream in each entity of the pipeline
- *
- */
-static void vimc_streamer_pipeline_terminate(struct vimc_stream *stream)
-{
-	struct vimc_ent_device *ved;
-	struct v4l2_subdev *sd;
-
-	while (stream->pipe_size) {
-		stream->pipe_size--;
-		ved = stream->ved_pipeline[stream->pipe_size];
-		stream->ved_pipeline[stream->pipe_size] = NULL;
-
-		if (!is_media_entity_v4l2_subdev(ved->ent))
-			continue;
-
-		sd = media_entity_to_v4l2_subdev(ved->ent);
-		v4l2_subdev_call(sd, video, s_stream, 0);
-	}
-}
-
 /**
  * vimc_streamer_pipeline_init - Initializes the stream structure
  *
@@ -82,27 +55,15 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 	struct media_entity *entity;
 	struct video_device *vdev;
 	struct v4l2_subdev *sd;
-	int ret = 0;
 
 	stream->pipe_size = 0;
 	while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
 		if (!ved) {
-			vimc_streamer_pipeline_terminate(stream);
+			stream->pipe_size = 0;
 			return -EINVAL;
 		}
 		stream->ved_pipeline[stream->pipe_size++] = ved;
 
-		if (is_media_entity_v4l2_subdev(ved->ent)) {
-			sd = media_entity_to_v4l2_subdev(ved->ent);
-			ret = v4l2_subdev_call(sd, video, s_stream, 1);
-			if (ret && ret != -ENOIOCTLCMD) {
-				dev_err(ved->dev, "subdev_call error %s\n",
-					ved->ent->name);
-				vimc_streamer_pipeline_terminate(stream);
-				return ret;
-			}
-		}
-
 		entity = vimc_get_source_entity(ved->ent);
 		/* Check if the end of the pipeline was reached */
 		if (!entity) {
@@ -111,7 +72,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 				dev_err(ved->dev,
 					"first entity in the pipe '%s' is not a source\n",
 					ved->ent->name);
-				vimc_streamer_pipeline_terminate(stream);
+				stream->pipe_size = 0;
 				return -EPIPE;
 			}
 			return 0;
@@ -129,7 +90,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 		}
 	}
 
-	vimc_streamer_pipeline_terminate(stream);
+	stream->pipe_size = 0;
 	return -EINVAL;
 }
 
@@ -210,7 +171,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
 		if (IS_ERR(stream->kthread)) {
 			ret = PTR_ERR(stream->kthread);
 			dev_err(ved->dev, "kthread_run failed with %d\n", ret);
-			vimc_streamer_pipeline_terminate(stream);
+			stream->pipe_size = 0;
 			stream->kthread = NULL;
 			return ret;
 		}
@@ -231,7 +192,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
 
 		stream->kthread = NULL;
 
-		vimc_streamer_pipeline_terminate(stream);
+		stream->pipe_size = 0;
 	}
 
 	return 0;
-- 
2.17.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable}
  2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
                   ` (4 preceding siblings ...)
  2020-05-22  7:55 ` [PATCH v4 5/5] media: vimc: " Dafna Hirschfeld
@ 2020-05-22  9:06 ` Helen Koike
  5 siblings, 0 replies; 11+ messages in thread
From: Helen Koike @ 2020-05-22  9:06 UTC (permalink / raw)
  To: Dafna Hirschfeld, linux-media, laurent.pinchart
  Cc: ezequiel, hverkuil, kernel, dafna3, sakari.ailus, linux-rockchip,
	mchehab, tfiga, skhan, niklas.soderlund

Hi Dafna,

Thanks for working on this.

On 5/22/20 4:55 AM, Dafna Hirschfeld wrote:
> Hi,
> This is v4 of the patchset that was sent by Helen Koike.
> 
> Media drivers need to iterate through the pipeline and call .s_stream()
> callbacks in the subdevices.
> 
> Instead of repeating code, add helpers for this.
> 
> These helpers will go walk through the pipeline only visiting entities
> that participates in the stream, i.e. it follows links from sink to source
> (and not the opposite).
> For example, in a topology like this https://bit.ly/3b2MxjI
> calling v4l2_pipeline_stream_enable() from rkisp1_mainpath won't call
> .s_stream(true) for rkisp1_resizer_selfpath.
> 
> stream_count variable was added in v4l2_subdevice to handle nested calls
> to the helpers.
> This is useful when the driver allows streaming from more then one
> capture device sharing subdevices.

If I understand correctly, this isn't  true anymore right? Nested calls aren't
possible anymore since this version doesn't contain stream_count in struct v4l2_subdevice.

Documentation of v4l2_pipeline_stream_*() should also be updated.

Just to be clear, without the nested call, vimc will require to add its own
counters, patch https://patchwork.kernel.org/patch/10948833/ will be
required again to allow multi streaming.

Also, patch "media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable}"
is cleaner in the previous version (with stream_count in struct v4l2_subdevice).

All drivers that allows multi streaming will need to implement some special handling.

Adding stream_count in struct v4l2_subdevice still seems cleaner to me. I'd like to hear
what others think.

> 
> This patchset was tested on rkisp1 and vimc drivers.
> 
> Other cleanup might be possible (but I won't add in this patchset as I
> don't have the hw to test):
> 	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/qcom/camss/camss-video.c#n430
> 	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/omap3isp/isp.c#n697
> 	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/stm32/stm32-dcmi.c#n680
> 	https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/xilinx/xilinx-dma.c#n97
> 
> Testing:
> --------
> 
> SEN_DEV=/dev/v4l-subdev3
> ISP_DEV=/dev/v4l-subdev0
> RSZ_SP_DEV=/dev/v4l-subdev2
> RSZ_MP_DEV=/dev/v4l-subdev1
> CAP_SP_DEV=/dev/video1
> CAP_MP_DEV=/dev/video0
> 
> WIDTH=1920
> HEIGHT=1080
> RAW_CODE=SRGGB10_1X10
> YUV_CODE=YUYV8_2X8
> 
> v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $SEN_DEV
> 
> v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $ISP_DEV
> v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV
> 
> v4l2-ctl --set-subdev-selection pad=2,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV
> v4l2-ctl --set-subdev-fmt pad=2,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $ISP_DEV
> 
> v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV
> v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV
> 
> v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_SP_DEV
> 
> v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV
> v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV
> 
> v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_MP_DEV
> 
> v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_SP_DEV
> v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_MP_DEV
> 
> sleep 1
> 
> v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_SP_DEV --stream-to=/tmp/test_sp.raw &
> v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_MP_DEV --stream-to=/tmp/test_mp.raw &
> 
> wait
> echo "Completed"
> 
> 
> Changes in v4:
> ==============
> patch 1: fix coding style issues
> 
> patch 2:
> - in function v4l2_pipeline_subdevs_get, use a local media_graph to walk on the topology so a lock is not needed
> and also the pipe parameter is not needed.

You are assuming that media_pipeline_start() will always be called before v4l2_pipeline_stream_enable().
I think this is fine, but it should reflect in the docs.

Regards,
Helen

> - adding a function v4l2_subdevs_stream_disable to avoid code duplication
> - change v4l2_pipeline_stream_disable to return an error code if failed
> - don't add a new field to subdevice "stream_counter" when calling s_stream, since this counter is updated only in
> the helper functions, and might be confusing that it is generally not an indication of the number of calls to s_stream.
> Also, except of rkisp1, and vimc, it seems that the other drivers that might use the new helpers don't use a counter.
> 
> new added - patch 3: the call to media_pipeline_start should be called before calling s_stream on the subdevices in order
> to validate the links and prevents them from changing, this patch fixes it.
> 
> patch 4: (use the helpers in rkisp1). The helpers now don't have a counter for the number of calls to s_stream, so rkisp1
> should check if the other capture is streaming and in that case call s_stream only for its resizer.
> 
> patch 5: - (use the helpers in vimc)
> - test the return value of v4l2_pipeline_stream_disable
> - the call to the helerps now doesn't need the pipe parameter.
> 
> Overview of patches in V3:
> --------------------------
> 
> Patch 1/5 adds a new iterator function in media-controller to follow links from sink to
> source only.
> 
> Patch 2/5 adds the helpers in v4l2-common.c,
> 
> Patch 3/5 calles media_pipeline_start before calling s_stream on the subdevices
> 
> Patch 4/5 cleanup rkisp1 driver to use the helpers.
> 
> Patch 5/5 cleanup vimc driver to use the helpers.
> 
> Changes in V3:
> ====================
> Following up Niklas' comments in V2 https://patchwork.kernel.org/patch/11473681/#23270823
> 
> * I removed the limitation in topologies with entities with multiple enabled
> links to its sink pads in the topology.
> Now it enables all subdevs in the pipeline that have an enabled link going
> from sink to source while walking from the video device, so it can be
> also useful for rcar-vin driver.
> 
> To implement this, I added back in the series the patch from v1:
>     "media: mc-entity.c: add media_graph_walk_next_stream()"
> 
> * "size" was renamed to "max_size" in function v4l2_pipeline_subdevs_get()
> to reflect the maximum number of elements that can fit in the subdevs array,
> with proper documentation.
> 
> * v4l2_pipeline_subdevs_get() returns a negative number for error, instead
> of returning 0 and printing a warning.
> 
> * I also add if defined(CONFIG_MEDIA_CONTROLLER) around helpers to avoid
> compiling errors.
> 
> Overview of patches in V3:
> --------------------------
> 
> Patch 1/4 adds a new iterator function in media-controller to follow links from sink to
> source only.
> 
> Patch 2/4 adds the helpers in v4l2-common.c, allowing nested calls by
> adding stream_count in the subdevice struct.
> 
> Patch 3/4 cleanup rkisp1 driver to use the helpers.
> 
> Patch 4/4 cleanup vimc driver to use the helpers.
> 
> Changes in V2:
> ====================
> The first version was calling the s_stream() callbacks from sensor to
> capture.
> 
> This was generating errors in the Scarlet Chromebook, when the sensor
> was being enabled before the ISP.
> 
> It make sense to enable subdevices from capture to sensor instead (which
> is what most drivers do already).
> 
> This v2 drops the changes from mc-entity.c, and re-implement helpers in
> v4l2-common.c
> 
> Overview of patches in V2:
> --------------------------
> 
> Path 1/3 adds the helpers in v4l2-common.c, allowing nested calls by
> adding stream_count in the subdevice struct.
> 
> Patch 2/3 cleanup rkisp1 driver to use the helpers.
> 
> Patch 3/3 cleanup vimc driver to use the helpers.
> 
> Dafna Hirschfeld (1):
>   media: staging: rkisp1: validate links before powering and streaming
> 
> Helen Koike (4):
>   media: mc-entity.c: add media_graph_walk_next_stream()
>   media: v4l2-common: add helper functions to call s_stream() callbacks
>   media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable}
>     helpers
>   media: vimc: use v4l2_pipeline_stream_{enable,disable} helpers
> 
>  drivers/media/mc/mc-entity.c                  |  34 ++++-
>  .../media/test-drivers/vimc/vimc-capture.c    |  31 +++--
>  .../media/test-drivers/vimc/vimc-streamer.c   |  49 +------
>  drivers/media/v4l2-core/v4l2-common.c         |  99 ++++++++++++++
>  drivers/staging/media/rkisp1/rkisp1-capture.c | 125 ++++++------------
>  include/media/media-entity.h                  |  15 +++
>  include/media/v4l2-common.h                   |  39 ++++++
>  7 files changed, 253 insertions(+), 139 deletions(-)
> 

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks
  2020-05-22  7:55 ` [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks Dafna Hirschfeld
@ 2020-05-25  9:23   ` Sakari Ailus
  2020-05-25  9:42     ` Dafna Hirschfeld
  0 siblings, 1 reply; 11+ messages in thread
From: Sakari Ailus @ 2020-05-25  9:23 UTC (permalink / raw)
  To: Dafna Hirschfeld
  Cc: linux-media, laurent.pinchart, helen.koike, ezequiel, hverkuil,
	kernel, dafna3, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

Hi Dafna,

My apologies for not reviewing this earlier.

On Fri, May 22, 2020 at 09:55:19AM +0200, Dafna Hirschfeld wrote:
> From: Helen Koike <helen.koike@collabora.com>
> 
> Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
> through the subdevices in a given stream (i.e following links from sink
> to source) and call .s_stream() callback.
> 
> If .s_stream(true) fails, call .s_stream(false) in the reverse order.
> 
> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> ---
>  drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
>  include/media/v4l2-common.h           | 39 +++++++++++
>  2 files changed, 138 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index 9e8eb45a5b03..734db2bf5ca9 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
> +
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> +
> +/*
> + * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline
> + * @subdevs: the array to be filled.
> + * @max_size: max number of elements that can fit in subdevs array.
> + *
> + * Walk from a video node, following links from sink to source and fill the
> + * array with subdevices in the path.
> + * The walker performs a depth-first traversal, which means that, in a topology
> + * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array.
> + *
> + * Return the number of subdevices filled in the array.
> + */
> +static int v4l2_pipeline_subdevs_get(struct video_device *vdev,
> +				     struct v4l2_subdev **subdevs,
> +				     unsigned int max_size)
> +{
> +	struct media_entity *entity = &vdev->entity;
> +	struct media_device *mdev = entity->graph_obj.mdev;
> +	struct media_graph graph;
> +	int idx = 0;
> +	int ret;
> +
> +	ret = media_graph_walk_init(&graph, mdev);
> +	if (ret)
> +		return ret;
> +
> +	media_graph_walk_start(&graph, entity);
> +
> +	while ((entity = media_graph_walk_next_stream(&graph))) {
> +		if (!is_media_entity_v4l2_subdev(entity))
> +			continue;
> +		if (WARN_ON(idx >= max_size))
> +			return -EINVAL;
> +		subdevs[idx++] = media_entity_to_v4l2_subdev(entity);
> +	}
> +
> +	media_graph_walk_cleanup(&graph);
> +
> +	return idx;
> +}
> +
> +static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size)
> +{
> +	int i;
> +
> +	for (i = 0; i < size; i++) {
> +		struct v4l2_subdev *sd = subdevs[i];
> +
> +		dev_dbg(sd->dev,
> +			"disabling stream for '%s'\n", sd->entity.name);
> +		v4l2_subdev_call(sd, video, s_stream, false);
> +	}
> +}
> +
> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev)
> +{
> +	struct media_device *mdev = vdev->entity.graph_obj.mdev;
> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
> +	struct v4l2_subdev *sd;
> +	int i, size, ret;
> +
> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
> +	if (size <= 0)
> +		return size;
> +
> +	/* Call s_stream() in reverse order to enable sensors last */
> +	for (i = size - 1; i >= 0; i--) {
> +		sd = subdevs[i];
> +		dev_dbg(mdev->dev,
> +			"enabling stream for '%s'\n", sd->entity.name);
> +		ret = v4l2_subdev_call(sd, video, s_stream, true);

The s_stream callback is only called on the very next sub-device upstream
in the pipeline, not on any further sub-devices. This is because a driver
for the device knows best in which order things need to be set up.

This could include, for instance, telling a sensor to place its CSI-2
transmitter to LP-11 state.

> +		if (ret && ret != -ENOIOCTLCMD) {
> +			v4l2_subdevs_stream_disable(subdevs + i + 1,
> +						    size - i - 1);
> +			return ret;
> +		}
> +	}
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
> +
> +int v4l2_pipeline_stream_disable(struct video_device *vdev)
> +{
> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
> +	int size;
> +
> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
> +	if (size < 0)
> +		return size;
> +
> +	v4l2_subdevs_stream_disable(subdevs, size);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
> +
> +#endif /* CONFIG_MEDIA_CONTROLLER */
> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> index 150ee16ebd81..a278bcf3c5bc 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
>  	buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
>  }
>  
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> +
> +/**
> + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
> + * @vdev: Starting video device.
> + *
> + * Call .s_stream(true) callback in all the subdevices participating in the
> + * stream, i.e. following links from sink to source.
> + *
> + * .s_stream(true) is also called from sink to source, i.e. in a topology
> + * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first.
> + *
> + * Calls to this function can be nested, in which case the same number of
> + * v4l2_pipeline_stream_disable() calls will be required to disable streaming
> + * through subdevices in the pipeline.
> + * The  pipeline pointer must be identical for all nested calls to
> + * v4l2_pipeline_stream_enable().
> + */
> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev);
> +
> +/**
> + * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream
> + * @vdev: Starting video device.
> + *
> + * Call .s_stream(false) callback in all the subdevices participating in the
> + * stream, i.e. following links from sink to source.
> + *
> + * s_stream(false) is called in a reverse order from
> + * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev,
> + * .s_stream(false) of sd1 is called first.
> + *
> + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same
> + * number of calls to this function are required to disable streaming through
> + * subdevices in the pipeline.
> + */
> +int v4l2_pipeline_stream_disable(struct video_device *vdev);
> +
> +#endif /* CONFIG_MEDIA_CONTROLLER */
> +
>  #endif /* V4L2_COMMON_H_ */

-- 
Kind regards,

Sakari Ailus

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks
  2020-05-25  9:23   ` Sakari Ailus
@ 2020-05-25  9:42     ` Dafna Hirschfeld
  2020-05-25 10:03       ` Sakari Ailus
  0 siblings, 1 reply; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-25  9:42 UTC (permalink / raw)
  To: Sakari Ailus
  Cc: linux-media, laurent.pinchart, helen.koike, ezequiel, hverkuil,
	kernel, dafna3, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund



On 25.05.20 11:23, Sakari Ailus wrote:
> Hi Dafna,
> 
> My apologies for not reviewing this earlier.
No problem :)

> 
> On Fri, May 22, 2020 at 09:55:19AM +0200, Dafna Hirschfeld wrote:
>> From: Helen Koike <helen.koike@collabora.com>
>>
>> Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
>> through the subdevices in a given stream (i.e following links from sink
>> to source) and call .s_stream() callback.
>>
>> If .s_stream(true) fails, call .s_stream(false) in the reverse order.
>>
>> Signed-off-by: Helen Koike <helen.koike@collabora.com>
>> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
>> ---
>>   drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
>>   include/media/v4l2-common.h           | 39 +++++++++++
>>   2 files changed, 138 insertions(+)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
>> index 9e8eb45a5b03..734db2bf5ca9 100644
>> --- a/drivers/media/v4l2-core/v4l2-common.c
>> +++ b/drivers/media/v4l2-core/v4l2-common.c
>> @@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
>>   	return 0;
>>   }
>>   EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
>> +
>> +#if defined(CONFIG_MEDIA_CONTROLLER)
>> +
>> +/*
>> + * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline
>> + * @subdevs: the array to be filled.
>> + * @max_size: max number of elements that can fit in subdevs array.
>> + *
>> + * Walk from a video node, following links from sink to source and fill the
>> + * array with subdevices in the path.
>> + * The walker performs a depth-first traversal, which means that, in a topology
>> + * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array.
>> + *
>> + * Return the number of subdevices filled in the array.
>> + */
>> +static int v4l2_pipeline_subdevs_get(struct video_device *vdev,
>> +				     struct v4l2_subdev **subdevs,
>> +				     unsigned int max_size)
>> +{
>> +	struct media_entity *entity = &vdev->entity;
>> +	struct media_device *mdev = entity->graph_obj.mdev;
>> +	struct media_graph graph;
>> +	int idx = 0;
>> +	int ret;
>> +
>> +	ret = media_graph_walk_init(&graph, mdev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	media_graph_walk_start(&graph, entity);
>> +
>> +	while ((entity = media_graph_walk_next_stream(&graph))) {
>> +		if (!is_media_entity_v4l2_subdev(entity))
>> +			continue;
>> +		if (WARN_ON(idx >= max_size))
>> +			return -EINVAL;
>> +		subdevs[idx++] = media_entity_to_v4l2_subdev(entity);
>> +	}
>> +
>> +	media_graph_walk_cleanup(&graph);
>> +
>> +	return idx;
>> +}
>> +
>> +static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < size; i++) {
>> +		struct v4l2_subdev *sd = subdevs[i];
>> +
>> +		dev_dbg(sd->dev,
>> +			"disabling stream for '%s'\n", sd->entity.name);
>> +		v4l2_subdev_call(sd, video, s_stream, false);
>> +	}
>> +}
>> +
>> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev)
>> +{
>> +	struct media_device *mdev = vdev->entity.graph_obj.mdev;
>> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
>> +	struct v4l2_subdev *sd;
>> +	int i, size, ret;
>> +
>> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
>> +	if (size <= 0)
>> +		return size;
>> +
>> +	/* Call s_stream() in reverse order to enable sensors last */
>> +	for (i = size - 1; i >= 0; i--) {
>> +		sd = subdevs[i];
>> +		dev_dbg(mdev->dev,
>> +			"enabling stream for '%s'\n", sd->entity.name);
>> +		ret = v4l2_subdev_call(sd, video, s_stream, true);
> 
> The s_stream callback is only called on the very next sub-device upstream
> in the pipeline, not on any further sub-devices. This is because a driver
> for the device knows best in which order things need to be set up.
> 
This is only a helper function, drivers can choose not to use it.
In many cases the same driver implements many subdevices so the driver
knows what should be done also for subdevices deeper in the stream.
In the cover letter of the patch there is a list of links to code parts
that can be replaced by this helper functions.
The cover letter: https://patchwork.kernel.org/cover/11564901/

Thanks,
Dafna

> This could include, for instance, telling a sensor to place its CSI-2
> transmitter to LP-11 state.
> 
>> +		if (ret && ret != -ENOIOCTLCMD) {
>> +			v4l2_subdevs_stream_disable(subdevs + i + 1,
>> +						    size - i - 1);
>> +			return ret;
>> +		}
>> +	}
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
>> +
>> +int v4l2_pipeline_stream_disable(struct video_device *vdev)
>> +{
>> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
>> +	int size;
>> +
>> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
>> +	if (size < 0)
>> +		return size;
>> +
>> +	v4l2_subdevs_stream_disable(subdevs, size);
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
>> +
>> +#endif /* CONFIG_MEDIA_CONTROLLER */
>> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
>> index 150ee16ebd81..a278bcf3c5bc 100644
>> --- a/include/media/v4l2-common.h
>> +++ b/include/media/v4l2-common.h
>> @@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
>>   	buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
>>   }
>>   
>> +#if defined(CONFIG_MEDIA_CONTROLLER)
>> +
>> +/**
>> + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
>> + * @vdev: Starting video device.
>> + *
>> + * Call .s_stream(true) callback in all the subdevices participating in the
>> + * stream, i.e. following links from sink to source.
>> + *
>> + * .s_stream(true) is also called from sink to source, i.e. in a topology
>> + * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first.
>> + *
>> + * Calls to this function can be nested, in which case the same number of
>> + * v4l2_pipeline_stream_disable() calls will be required to disable streaming
>> + * through subdevices in the pipeline.
>> + * The  pipeline pointer must be identical for all nested calls to
>> + * v4l2_pipeline_stream_enable().
>> + */
>> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev);
>> +
>> +/**
>> + * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream
>> + * @vdev: Starting video device.
>> + *
>> + * Call .s_stream(false) callback in all the subdevices participating in the
>> + * stream, i.e. following links from sink to source.
>> + *
>> + * s_stream(false) is called in a reverse order from
>> + * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev,
>> + * .s_stream(false) of sd1 is called first.
>> + *
>> + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same
>> + * number of calls to this function are required to disable streaming through
>> + * subdevices in the pipeline.
>> + */
>> +int v4l2_pipeline_stream_disable(struct video_device *vdev);
>> +
>> +#endif /* CONFIG_MEDIA_CONTROLLER */
>> +
>>   #endif /* V4L2_COMMON_H_ */
> 

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks
  2020-05-25  9:42     ` Dafna Hirschfeld
@ 2020-05-25 10:03       ` Sakari Ailus
  2020-05-25 10:45         ` Dafna Hirschfeld
  0 siblings, 1 reply; 11+ messages in thread
From: Sakari Ailus @ 2020-05-25 10:03 UTC (permalink / raw)
  To: Dafna Hirschfeld
  Cc: linux-media, laurent.pinchart, helen.koike, ezequiel, hverkuil,
	kernel, dafna3, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund

Hi Dafna,

On Mon, May 25, 2020 at 11:42:37AM +0200, Dafna Hirschfeld wrote:
> 
> 
> On 25.05.20 11:23, Sakari Ailus wrote:
> > Hi Dafna,
> > 
> > My apologies for not reviewing this earlier.
> No problem :)
> 
> > 
> > On Fri, May 22, 2020 at 09:55:19AM +0200, Dafna Hirschfeld wrote:
> > > From: Helen Koike <helen.koike@collabora.com>
> > > 
> > > Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
> > > through the subdevices in a given stream (i.e following links from sink
> > > to source) and call .s_stream() callback.
> > > 
> > > If .s_stream(true) fails, call .s_stream(false) in the reverse order.
> > > 
> > > Signed-off-by: Helen Koike <helen.koike@collabora.com>
> > > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> > > ---
> > >   drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
> > >   include/media/v4l2-common.h           | 39 +++++++++++
> > >   2 files changed, 138 insertions(+)
> > > 
> > > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> > > index 9e8eb45a5b03..734db2bf5ca9 100644
> > > --- a/drivers/media/v4l2-core/v4l2-common.c
> > > +++ b/drivers/media/v4l2-core/v4l2-common.c
> > > @@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
> > >   	return 0;
> > >   }
> > >   EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
> > > +
> > > +#if defined(CONFIG_MEDIA_CONTROLLER)
> > > +
> > > +/*
> > > + * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline
> > > + * @subdevs: the array to be filled.
> > > + * @max_size: max number of elements that can fit in subdevs array.
> > > + *
> > > + * Walk from a video node, following links from sink to source and fill the
> > > + * array with subdevices in the path.
> > > + * The walker performs a depth-first traversal, which means that, in a topology
> > > + * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array.
> > > + *
> > > + * Return the number of subdevices filled in the array.
> > > + */
> > > +static int v4l2_pipeline_subdevs_get(struct video_device *vdev,
> > > +				     struct v4l2_subdev **subdevs,
> > > +				     unsigned int max_size)
> > > +{
> > > +	struct media_entity *entity = &vdev->entity;
> > > +	struct media_device *mdev = entity->graph_obj.mdev;
> > > +	struct media_graph graph;
> > > +	int idx = 0;
> > > +	int ret;
> > > +
> > > +	ret = media_graph_walk_init(&graph, mdev);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	media_graph_walk_start(&graph, entity);
> > > +
> > > +	while ((entity = media_graph_walk_next_stream(&graph))) {
> > > +		if (!is_media_entity_v4l2_subdev(entity))
> > > +			continue;
> > > +		if (WARN_ON(idx >= max_size))
> > > +			return -EINVAL;
> > > +		subdevs[idx++] = media_entity_to_v4l2_subdev(entity);
> > > +	}
> > > +
> > > +	media_graph_walk_cleanup(&graph);
> > > +
> > > +	return idx;
> > > +}
> > > +
> > > +static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size)
> > > +{
> > > +	int i;
> > > +
> > > +	for (i = 0; i < size; i++) {
> > > +		struct v4l2_subdev *sd = subdevs[i];
> > > +
> > > +		dev_dbg(sd->dev,
> > > +			"disabling stream for '%s'\n", sd->entity.name);
> > > +		v4l2_subdev_call(sd, video, s_stream, false);
> > > +	}
> > > +}
> > > +
> > > +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev)
> > > +{
> > > +	struct media_device *mdev = vdev->entity.graph_obj.mdev;
> > > +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
> > > +	struct v4l2_subdev *sd;
> > > +	int i, size, ret;
> > > +
> > > +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
> > > +	if (size <= 0)
> > > +		return size;
> > > +
> > > +	/* Call s_stream() in reverse order to enable sensors last */
> > > +	for (i = size - 1; i >= 0; i--) {
> > > +		sd = subdevs[i];
> > > +		dev_dbg(mdev->dev,
> > > +			"enabling stream for '%s'\n", sd->entity.name);
> > > +		ret = v4l2_subdev_call(sd, video, s_stream, true);
> > 
> > The s_stream callback is only called on the very next sub-device upstream
> > in the pipeline, not on any further sub-devices. This is because a driver
> > for the device knows best in which order things need to be set up.
> > 
> This is only a helper function, drivers can choose not to use it.
> In many cases the same driver implements many subdevices so the driver
> knows what should be done also for subdevices deeper in the stream.

Can it be used on devices that do not operate from memory to memory? I.e.
how do you ensure the s_stream is not called on further sub-devices than
those that are adjacent to what this driver controls?

One option could be to check sd->dev and skip devices that are further away
but for that you'd also need to know how these sub-devices have been
reached. The graph walk does not currently provide this information.

It's true that many drivers implement similar functionality for streaming.
It's non-trivial but often makes use of some device specific knowledge, for
instance in which order things take place (such as whether the upstream
sub-device is started before the downstream one). These implementations
also do not use graph walk for the above reasons.

> In the cover letter of the patch there is a list of links to code parts
> that can be replaced by this helper functions.
> The cover letter: https://patchwork.kernel.org/cover/11564901/
> 
> Thanks,
> Dafna
> 
> > This could include, for instance, telling a sensor to place its CSI-2
> > transmitter to LP-11 state.
> > 
> > > +		if (ret && ret != -ENOIOCTLCMD) {
> > > +			v4l2_subdevs_stream_disable(subdevs + i + 1,
> > > +						    size - i - 1);
> > > +			return ret;
> > > +		}
> > > +	}
> > > +	return 0;
> > > +}
> > > +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
> > > +
> > > +int v4l2_pipeline_stream_disable(struct video_device *vdev)
> > > +{
> > > +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
> > > +	int size;
> > > +
> > > +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
> > > +	if (size < 0)
> > > +		return size;
> > > +
> > > +	v4l2_subdevs_stream_disable(subdevs, size);
> > > +	return 0;
> > > +}
> > > +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
> > > +
> > > +#endif /* CONFIG_MEDIA_CONTROLLER */
> > > diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> > > index 150ee16ebd81..a278bcf3c5bc 100644
> > > --- a/include/media/v4l2-common.h
> > > +++ b/include/media/v4l2-common.h
> > > @@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
> > >   	buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
> > >   }
> > > +#if defined(CONFIG_MEDIA_CONTROLLER)
> > > +
> > > +/**
> > > + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
> > > + * @vdev: Starting video device.
> > > + *
> > > + * Call .s_stream(true) callback in all the subdevices participating in the
> > > + * stream, i.e. following links from sink to source.
> > > + *
> > > + * .s_stream(true) is also called from sink to source, i.e. in a topology
> > > + * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first.
> > > + *
> > > + * Calls to this function can be nested, in which case the same number of
> > > + * v4l2_pipeline_stream_disable() calls will be required to disable streaming
> > > + * through subdevices in the pipeline.
> > > + * The  pipeline pointer must be identical for all nested calls to
> > > + * v4l2_pipeline_stream_enable().
> > > + */
> > > +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev);
> > > +
> > > +/**
> > > + * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream
> > > + * @vdev: Starting video device.
> > > + *
> > > + * Call .s_stream(false) callback in all the subdevices participating in the
> > > + * stream, i.e. following links from sink to source.
> > > + *
> > > + * s_stream(false) is called in a reverse order from
> > > + * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev,
> > > + * .s_stream(false) of sd1 is called first.
> > > + *
> > > + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same
> > > + * number of calls to this function are required to disable streaming through
> > > + * subdevices in the pipeline.
> > > + */
> > > +int v4l2_pipeline_stream_disable(struct video_device *vdev);
> > > +
> > > +#endif /* CONFIG_MEDIA_CONTROLLER */
> > > +
> > >   #endif /* V4L2_COMMON_H_ */
> > 

-- 
Sakari Ailus

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks
  2020-05-25 10:03       ` Sakari Ailus
@ 2020-05-25 10:45         ` Dafna Hirschfeld
  0 siblings, 0 replies; 11+ messages in thread
From: Dafna Hirschfeld @ 2020-05-25 10:45 UTC (permalink / raw)
  To: Sakari Ailus
  Cc: linux-media, laurent.pinchart, helen.koike, ezequiel, hverkuil,
	kernel, dafna3, linux-rockchip, mchehab, tfiga, skhan,
	niklas.soderlund



On 25.05.20 12:03, Sakari Ailus wrote:
> Hi Dafna,
> 
> On Mon, May 25, 2020 at 11:42:37AM +0200, Dafna Hirschfeld wrote:
>>
>>
>> On 25.05.20 11:23, Sakari Ailus wrote:
>>> Hi Dafna,
>>>
>>> My apologies for not reviewing this earlier.
>> No problem :)
>>
>>>
>>> On Fri, May 22, 2020 at 09:55:19AM +0200, Dafna Hirschfeld wrote:
>>>> From: Helen Koike <helen.koike@collabora.com>
>>>>
>>>> Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
>>>> through the subdevices in a given stream (i.e following links from sink
>>>> to source) and call .s_stream() callback.
>>>>
>>>> If .s_stream(true) fails, call .s_stream(false) in the reverse order.
>>>>
>>>> Signed-off-by: Helen Koike <helen.koike@collabora.com>
>>>> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
>>>> ---
>>>>    drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
>>>>    include/media/v4l2-common.h           | 39 +++++++++++
>>>>    2 files changed, 138 insertions(+)
>>>>
>>>> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
>>>> index 9e8eb45a5b03..734db2bf5ca9 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-common.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-common.c
>>>> @@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
>>>>    	return 0;
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
>>>> +
>>>> +#if defined(CONFIG_MEDIA_CONTROLLER)
>>>> +
>>>> +/*
>>>> + * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline
>>>> + * @subdevs: the array to be filled.
>>>> + * @max_size: max number of elements that can fit in subdevs array.
>>>> + *
>>>> + * Walk from a video node, following links from sink to source and fill the
>>>> + * array with subdevices in the path.
>>>> + * The walker performs a depth-first traversal, which means that, in a topology
>>>> + * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array.
>>>> + *
>>>> + * Return the number of subdevices filled in the array.
>>>> + */
>>>> +static int v4l2_pipeline_subdevs_get(struct video_device *vdev,
>>>> +				     struct v4l2_subdev **subdevs,
>>>> +				     unsigned int max_size)
>>>> +{
>>>> +	struct media_entity *entity = &vdev->entity;
>>>> +	struct media_device *mdev = entity->graph_obj.mdev;
>>>> +	struct media_graph graph;
>>>> +	int idx = 0;
>>>> +	int ret;
>>>> +
>>>> +	ret = media_graph_walk_init(&graph, mdev);
>>>> +	if (ret)
>>>> +		return ret;
>>>> +
>>>> +	media_graph_walk_start(&graph, entity);
>>>> +
>>>> +	while ((entity = media_graph_walk_next_stream(&graph))) {
>>>> +		if (!is_media_entity_v4l2_subdev(entity))
>>>> +			continue;
>>>> +		if (WARN_ON(idx >= max_size))
>>>> +			return -EINVAL;
>>>> +		subdevs[idx++] = media_entity_to_v4l2_subdev(entity);
>>>> +	}
>>>> +
>>>> +	media_graph_walk_cleanup(&graph);
>>>> +
>>>> +	return idx;
>>>> +}
>>>> +
>>>> +static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	for (i = 0; i < size; i++) {
>>>> +		struct v4l2_subdev *sd = subdevs[i];
>>>> +
>>>> +		dev_dbg(sd->dev,
>>>> +			"disabling stream for '%s'\n", sd->entity.name);
>>>> +		v4l2_subdev_call(sd, video, s_stream, false);
>>>> +	}
>>>> +}
>>>> +
>>>> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev)
>>>> +{
>>>> +	struct media_device *mdev = vdev->entity.graph_obj.mdev;
>>>> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
>>>> +	struct v4l2_subdev *sd;
>>>> +	int i, size, ret;
>>>> +
>>>> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
>>>> +	if (size <= 0)
>>>> +		return size;
>>>> +
>>>> +	/* Call s_stream() in reverse order to enable sensors last */
>>>> +	for (i = size - 1; i >= 0; i--) {
>>>> +		sd = subdevs[i];
>>>> +		dev_dbg(mdev->dev,
>>>> +			"enabling stream for '%s'\n", sd->entity.name);
>>>> +		ret = v4l2_subdev_call(sd, video, s_stream, true);
>>>
>>> The s_stream callback is only called on the very next sub-device upstream
>>> in the pipeline, not on any further sub-devices. This is because a driver
>>> for the device knows best in which order things need to be set up.
>>>
>> This is only a helper function, drivers can choose not to use it.
>> In many cases the same driver implements many subdevices so the driver
>> knows what should be done also for subdevices deeper in the stream.
> 
> Can it be used on devices that do not operate from memory to memory? I.e.
> how do you ensure the s_stream is not called on further sub-devices than
> those that are adjacent to what this driver controls?
Oh, I think I see your point, for example in case of an isp driver and a sensor driver.
The sensor driver can also implement several subdevices that the isp driver is not
aware of and it is the responsibility of the sensor driver to call them.
Is this a common case? Still there are the code parts in drivers that are implementing
calling s_stream in a loop similar to those in the helper functions.
Maybe they are "buggy"?
For example this code part:
https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/qcom/camss/camss-video.c#n430
is called by the `start_stream` of a video device and I see that the
`camss_probe` function that register it also calls
v4l2_async_notifier_register, which means there might have a subdevice
from a different driver.

Anyway, for the rkisp1 it is probably problematic since it is connected to a sensor
implemented by another driver.
  
> 
> One option could be to check sd->dev and skip devices that are further away
> but for that you'd also need to know how these sub-devices have been
> reached. The graph walk does not currently provide this information.
I think it is possible to use the sd->dev (or maybe sd-owner?)
since we always only go down the stream, so when we reach a subdevice from
a different driver we can stop. (not sure though)

Thanks,
Dafna

> 
> It's true that many drivers implement similar functionality for streaming.
> It's non-trivial but often makes use of some device specific knowledge, for
> instance in which order things take place (such as whether the upstream
> sub-device is started before the downstream one). These implementations
> also do not use graph walk for the above reasons.
> 
>> In the cover letter of the patch there is a list of links to code parts
>> that can be replaced by this helper functions.
>> The cover letter: https://patchwork.kernel.org/cover/11564901/
>>
>> Thanks,
>> Dafna
>>
>>> This could include, for instance, telling a sensor to place its CSI-2
>>> transmitter to LP-11 state.
>>>
>>>> +		if (ret && ret != -ENOIOCTLCMD) {
>>>> +			v4l2_subdevs_stream_disable(subdevs + i + 1,
>>>> +						    size - i - 1);
>>>> +			return ret;
>>>> +		}
>>>> +	}
>>>> +	return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
>>>> +
>>>> +int v4l2_pipeline_stream_disable(struct video_device *vdev)
>>>> +{
>>>> +	struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH];
>>>> +	int size;
>>>> +
>>>> +	size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs));
>>>> +	if (size < 0)
>>>> +		return size;
>>>> +
>>>> +	v4l2_subdevs_stream_disable(subdevs, size);
>>>> +	return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
>>>> +
>>>> +#endif /* CONFIG_MEDIA_CONTROLLER */
>>>> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
>>>> index 150ee16ebd81..a278bcf3c5bc 100644
>>>> --- a/include/media/v4l2-common.h
>>>> +++ b/include/media/v4l2-common.h
>>>> @@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
>>>>    	buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
>>>>    }
>>>> +#if defined(CONFIG_MEDIA_CONTROLLER)
>>>> +
>>>> +/**
>>>> + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
>>>> + * @vdev: Starting video device.
>>>> + *
>>>> + * Call .s_stream(true) callback in all the subdevices participating in the
>>>> + * stream, i.e. following links from sink to source.
>>>> + *
>>>> + * .s_stream(true) is also called from sink to source, i.e. in a topology
>>>> + * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first.
>>>> + *
>>>> + * Calls to this function can be nested, in which case the same number of
>>>> + * v4l2_pipeline_stream_disable() calls will be required to disable streaming
>>>> + * through subdevices in the pipeline.
>>>> + * The  pipeline pointer must be identical for all nested calls to
>>>> + * v4l2_pipeline_stream_enable().
>>>> + */
>>>> +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev);
>>>> +
>>>> +/**
>>>> + * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream
>>>> + * @vdev: Starting video device.
>>>> + *
>>>> + * Call .s_stream(false) callback in all the subdevices participating in the
>>>> + * stream, i.e. following links from sink to source.
>>>> + *
>>>> + * s_stream(false) is called in a reverse order from
>>>> + * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev,
>>>> + * .s_stream(false) of sd1 is called first.
>>>> + *
>>>> + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same
>>>> + * number of calls to this function are required to disable streaming through
>>>> + * subdevices in the pipeline.
>>>> + */
>>>> +int v4l2_pipeline_stream_disable(struct video_device *vdev);
>>>> +
>>>> +#endif /* CONFIG_MEDIA_CONTROLLER */
>>>> +
>>>>    #endif /* V4L2_COMMON_H_ */
>>>
> 

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, back to index

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-22  7:55 [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Dafna Hirschfeld
2020-05-22  7:55 ` [PATCH v4 1/5] media: mc-entity.c: add media_graph_walk_next_stream() Dafna Hirschfeld
2020-05-22  7:55 ` [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks Dafna Hirschfeld
2020-05-25  9:23   ` Sakari Ailus
2020-05-25  9:42     ` Dafna Hirschfeld
2020-05-25 10:03       ` Sakari Ailus
2020-05-25 10:45         ` Dafna Hirschfeld
2020-05-22  7:55 ` [PATCH v4 3/5] media: staging: rkisp1: validate links before powering and streaming Dafna Hirschfeld
2020-05-22  7:55 ` [PATCH v4 4/5] media: staging: rkisp1: cap: use v4l2_pipeline_stream_{enable,disable} helpers Dafna Hirschfeld
2020-05-22  7:55 ` [PATCH v4 5/5] media: vimc: " Dafna Hirschfeld
2020-05-22  9:06 ` [PATCH v4 0/5] media: add v4l2_pipeline_stream_{enable,disable} Helen Koike

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