[PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

Please note that I am sending just the 4 patches that
changed during series rebase to Linux 4.5. The rebase
was pain free. media_device_init() type change required
changes to patches 18 and 26. I re-tested the series
and everything looks good.

[PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
[PATCH 18/31] media: au0828 change to use Managed Media Controller API
[PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
[PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

Links:
PATCH Series that contains all 31 patches:
https://lkml.org/lkml/2016/1/6/668

ALSA patches went through reviews and links
to PATCH V3 (ALSA):
https://lkml.org/lkml/2016/1/18/556
https://lkml.org/lkml/2016/1/18/557
https://lkml.org/lkml/2016/1/18/558

Compile warns patches:
https://lkml.org/lkml/2016/1/19/520
https://lkml.org/lkml/2016/1/19/518
https://lkml.org/lkml/2016/1/19/519

Mauro and Takashi:
Please let me know if you would rather see the entire
patch series generated for 4.5-rc1 and sent out in a
complete series instead of just the rebased patches.

Mauro Carvalho Chehab (1):
  uapi/media.h: Declare interface types for ALSA

Shuah Khan (30):
  media: Add ALSA Media Controller function entities
  media: Media Controller register/unregister entity_notify API
  media: Media Controller enable/disable source handler API
  media: Media Controller fix to not let stream_count go negative
  media: Media Controller export non locking __media_entity_setup_link()
  media: Media Controller non-locking
    __media_entity_pipeline_start/stop()
  media: v4l-core add v4l_enable/disable_media_tuner() helper functions
  media: v4l2-core add v4l_vb2q_enable_media_tuner() helper
  media: Move au8522_media_pads enum to au8522.h from au8522_priv.h
  media: au8522 change to create MC pad for ALSA Audio Out
  media: au0828 Use au8522_media_pads enum for pad defines
  media: au0828 fix au0828_create_media_graph() entity checks
  media: Change v4l-core to check for tuner availability
  media: dvb-frontend invoke enable/disable_source handlers
  media: au0828 video remove au0828_enable_analog_tuner()
  media: au0828 video change to use v4l_enable_media_tuner()
  media: au0828 change to use Managed Media Controller API
  media: au0828 handle media_init and media_register window
  media: au0828 change to register/unregister entity_notify hook
  media: au0828 create tuner to decoder link in deactivated state
  media: dvb-core create tuner to demod pad link in disabled state
  media: au0828 implement enable_source and disable_source handlers
  media: au0828 fix null pointer reference in
    au0828_create_media_graph()
  media: au0828 fix to not call media_device_unregister_entity_notify()
  sound/usb: Update ALSA driver to use Managed Media Controller API
  sound/usb: Create media mixer function and control interface entities
  media: au0828 create link between ALSA Mixer and decoder
  media: track media device unregister in progress
  sound/usb: Check media device unregister progress state
  media: au0828 change to check media device unregister progress state

 drivers/media/dvb-core/dvb_frontend.c        | 139 ++---------
 drivers/media/dvb-core/dvb_frontend.h        |   3 +
 drivers/media/dvb-core/dvbdev.c              |   4 +-
 drivers/media/dvb-frontends/au8522.h         |   8 +
 drivers/media/dvb-frontends/au8522_decoder.c |   1 +
 drivers/media/dvb-frontends/au8522_priv.h    |   8 -
 drivers/media/media-device.c                 |  66 +++++-
 drivers/media/media-entity.c                 |  65 +++--
 drivers/media/usb/au0828/au0828-core.c       | 340 +++++++++++++++++++++++----
 drivers/media/usb/au0828/au0828-video.c      |  75 +-----
 drivers/media/usb/au0828/au0828.h            |   9 +
 drivers/media/v4l2-core/v4l2-dev.c           |  48 ++++
 drivers/media/v4l2-core/v4l2-fh.c            |   1 +
 drivers/media/v4l2-core/v4l2-ioctl.c         |  29 +++
 drivers/media/v4l2-core/videobuf2-core.c     |   4 +
 include/media/media-device.h                 |  61 +++++
 include/media/media-entity.h                 |  12 +
 include/media/v4l2-dev.h                     |   5 +
 include/uapi/linux/media.h                   |  17 +-
 sound/usb/Kconfig                            |   4 +
 sound/usb/Makefile                           |   2 +
 sound/usb/card.c                             |  16 ++
 sound/usb/card.h                             |   1 +
 sound/usb/media.c                            | 299 +++++++++++++++++++++++
 sound/usb/media.h                            |  76 ++++++
 sound/usb/mixer.h                            |   1 +
 sound/usb/pcm.c                              |  28 ++-
 sound/usb/quirks-table.h                     |   1 +
 sound/usb/quirks.c                           |   5 +
 sound/usb/stream.c                           |   1 +
 sound/usb/usbaudio.h                         |   2 +
 31 files changed, 1070 insertions(+), 261 deletions(-)
 create mode 100644 sound/usb/media.c
 create mode 100644 sound/usb/media.h

-- 
2.5.0

[PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

Please note that I am sending just the 4 patches that
changed during series rebase to Linux 4.5. The rebase
was pain free. media_device_init() type change required
changes to patches 18 and 26. I re-tested the series
and everything looks good.

[PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
[PATCH 18/31] media: au0828 change to use Managed Media Controller API
[PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
[PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

Links:
PATCH Series that contains all 31 patches:
https://lkml.org/lkml/2016/1/6/668

ALSA patches went through reviews and links
to PATCH V3 (ALSA):
https://lkml.org/lkml/2016/1/18/556
https://lkml.org/lkml/2016/1/18/557
https://lkml.org/lkml/2016/1/18/558

Compile warns patches:
https://lkml.org/lkml/2016/1/19/520
https://lkml.org/lkml/2016/1/19/518
https://lkml.org/lkml/2016/1/19/519

Mauro and Takashi:
Please let me know if you would rather see the entire
patch series generated for 4.5-rc1 and sent out in a
complete series instead of just the rebased patches.

Mauro Carvalho Chehab (1):
  uapi/media.h: Declare interface types for ALSA

Shuah Khan (30):
  media: Add ALSA Media Controller function entities
  media: Media Controller register/unregister entity_notify API
  media: Media Controller enable/disable source handler API
  media: Media Controller fix to not let stream_count go negative
  media: Media Controller export non locking __media_entity_setup_link()
  media: Media Controller non-locking
    __media_entity_pipeline_start/stop()
  media: v4l-core add v4l_enable/disable_media_tuner() helper functions
  media: v4l2-core add v4l_vb2q_enable_media_tuner() helper
  media: Move au8522_media_pads enum to au8522.h from au8522_priv.h
  media: au8522 change to create MC pad for ALSA Audio Out
  media: au0828 Use au8522_media_pads enum for pad defines
  media: au0828 fix au0828_create_media_graph() entity checks
  media: Change v4l-core to check for tuner availability
  media: dvb-frontend invoke enable/disable_source handlers
  media: au0828 video remove au0828_enable_analog_tuner()
  media: au0828 video change to use v4l_enable_media_tuner()
  media: au0828 change to use Managed Media Controller API
  media: au0828 handle media_init and media_register window
  media: au0828 change to register/unregister entity_notify hook
  media: au0828 create tuner to decoder link in deactivated state
  media: dvb-core create tuner to demod pad link in disabled state
  media: au0828 implement enable_source and disable_source handlers
  media: au0828 fix null pointer reference in
    au0828_create_media_graph()
  media: au0828 fix to not call media_device_unregister_entity_notify()
  sound/usb: Update ALSA driver to use Managed Media Controller API
  sound/usb: Create media mixer function and control interface entities
  media: au0828 create link between ALSA Mixer and decoder
  media: track media device unregister in progress
  sound/usb: Check media device unregister progress state
  media: au0828 change to check media device unregister progress state

 drivers/media/dvb-core/dvb_frontend.c        | 139 ++---------
 drivers/media/dvb-core/dvb_frontend.h        |   3 +
 drivers/media/dvb-core/dvbdev.c              |   4 +-
 drivers/media/dvb-frontends/au8522.h         |   8 +
 drivers/media/dvb-frontends/au8522_decoder.c |   1 +
 drivers/media/dvb-frontends/au8522_priv.h    |   8 -
 drivers/media/media-device.c                 |  66 +++++-
 drivers/media/media-entity.c                 |  65 +++--
 drivers/media/usb/au0828/au0828-core.c       | 340 +++++++++++++++++++++++----
 drivers/media/usb/au0828/au0828-video.c      |  75 +-----
 drivers/media/usb/au0828/au0828.h            |   9 +
 drivers/media/v4l2-core/v4l2-dev.c           |  48 ++++
 drivers/media/v4l2-core/v4l2-fh.c            |   1 +
 drivers/media/v4l2-core/v4l2-ioctl.c         |  29 +++
 drivers/media/v4l2-core/videobuf2-core.c     |   4 +
 include/media/media-device.h                 |  61 +++++
 include/media/media-entity.h                 |  12 +
 include/media/v4l2-dev.h                     |   5 +
 include/uapi/linux/media.h                   |  17 +-
 sound/usb/Kconfig                            |   4 +
 sound/usb/Makefile                           |   2 +
 sound/usb/card.c                             |  16 ++
 sound/usb/card.h                             |   1 +
 sound/usb/media.c                            | 299 +++++++++++++++++++++++
 sound/usb/media.h                            |  76 ++++++
 sound/usb/mixer.h                            |   1 +
 sound/usb/pcm.c                              |  28 ++-
 sound/usb/quirks-table.h                     |   1 +
 sound/usb/quirks.c                           |   5 +
 sound/usb/stream.c                           |   1 +
 sound/usb/usbaudio.h                         |   2 +
 31 files changed, 1070 insertions(+), 261 deletions(-)
 create mode 100644 sound/usb/media.c
 create mode 100644 sound/usb/media.h

-- 
2.5.0

[PATCH REBASE 4.5 16/31] media: au0828 video remove au0828_enable_analog_tuner()

[Shuah Khan]

au0828_enable_analog_tuner() is no longer needed with
v4l2-core and au0828-video invoking enable_source and
disable_source handlers. In addition, it is unnecessary
to check for tuner availability in queue_setup() as
v4l2-core handles the tuner availability checks.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/usb/au0828/au0828-video.c | 61 ---------------------------------
 1 file changed, 61 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
index 8c54fd2..81952c8 100644
--- a/drivers/media/usb/au0828/au0828-video.c
+++ b/drivers/media/usb/au0828/au0828-video.c
@@ -638,64 +638,6 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
 	return rc;
 }
 
-static int au0828_enable_analog_tuner(struct au0828_dev *dev)
-{
-#ifdef CONFIG_MEDIA_CONTROLLER
-	struct media_device *mdev = dev->media_dev;
-	struct media_entity *source;
-	struct media_link *link, *found_link = NULL;
-	int ret, active_links = 0;
-
-	if (!mdev || !dev->decoder)
-		return 0;
-
-	/*
-	 * This will find the tuner that is connected into the decoder.
-	 * Technically, this is not 100% correct, as the device may be
-	 * using an analog input instead of the tuner. However, as we can't
-	 * do DVB streaming while the DMA engine is being used for V4L2,
-	 * this should be enough for the actual needs.
-	 */
-	list_for_each_entry(link, &dev->decoder->links, list) {
-		if (link->sink->entity == dev->decoder) {
-			found_link = link;
-			if (link->flags & MEDIA_LNK_FL_ENABLED)
-				active_links++;
-			break;
-		}
-	}
-
-	if (active_links == 1 || !found_link)
-		return 0;
-
-	source = found_link->source->entity;
-	list_for_each_entry(link, &source->links, list) {
-		struct media_entity *sink;
-		int flags = 0;
-
-		sink = link->sink->entity;
-
-		if (sink == dev->decoder)
-			flags = MEDIA_LNK_FL_ENABLED;
-
-		ret = media_entity_setup_link(link, flags);
-		if (ret) {
-			pr_err(
-				"Couldn't change link %s->%s to %s. Error %d\n",
-				source->name, sink->name,
-				flags ? "enabled" : "disabled",
-				ret);
-			return ret;
-		} else
-			au0828_isocdbg(
-				"link %s->%s was %s\n",
-				source->name, sink->name,
-				flags ? "ENABLED" : "disabled");
-	}
-#endif
-	return 0;
-}
-
 static int queue_setup(struct vb2_queue *vq,
 		       unsigned int *nbuffers, unsigned int *nplanes,
 		       unsigned int sizes[], void *alloc_ctxs[])
@@ -707,9 +649,6 @@ static int queue_setup(struct vb2_queue *vq,
 		return sizes[0] < size ? -EINVAL : 0;
 	*nplanes = 1;
 	sizes[0] = size;
-
-	au0828_enable_analog_tuner(dev);
-
 	return 0;
 }
 
-- 
2.5.0

[PATCH REBASE 4.5 16/31] media: au0828 video remove au0828_enable_analog_tuner()

[Shuah Khan]

au0828_enable_analog_tuner() is no longer needed with
v4l2-core and au0828-video invoking enable_source and
disable_source handlers. In addition, it is unnecessary
to check for tuner availability in queue_setup() as
v4l2-core handles the tuner availability checks.

Signed-off-by: Shuah Khan <shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
---
 drivers/media/usb/au0828/au0828-video.c | 61 ---------------------------------
 1 file changed, 61 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
index 8c54fd2..81952c8 100644
--- a/drivers/media/usb/au0828/au0828-video.c
+++ b/drivers/media/usb/au0828/au0828-video.c
@@ -638,64 +638,6 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
 	return rc;
 }
 
-static int au0828_enable_analog_tuner(struct au0828_dev *dev)
-{
-#ifdef CONFIG_MEDIA_CONTROLLER
-	struct media_device *mdev = dev->media_dev;
-	struct media_entity *source;
-	struct media_link *link, *found_link = NULL;
-	int ret, active_links = 0;
-
-	if (!mdev || !dev->decoder)
-		return 0;
-
-	/*
-	 * This will find the tuner that is connected into the decoder.
-	 * Technically, this is not 100% correct, as the device may be
-	 * using an analog input instead of the tuner. However, as we can't
-	 * do DVB streaming while the DMA engine is being used for V4L2,
-	 * this should be enough for the actual needs.
-	 */
-	list_for_each_entry(link, &dev->decoder->links, list) {
-		if (link->sink->entity == dev->decoder) {
-			found_link = link;
-			if (link->flags & MEDIA_LNK_FL_ENABLED)
-				active_links++;
-			break;
-		}
-	}
-
-	if (active_links == 1 || !found_link)
-		return 0;
-
-	source = found_link->source->entity;
-	list_for_each_entry(link, &source->links, list) {
-		struct media_entity *sink;
-		int flags = 0;
-
-		sink = link->sink->entity;
-
-		if (sink == dev->decoder)
-			flags = MEDIA_LNK_FL_ENABLED;
-
-		ret = media_entity_setup_link(link, flags);
-		if (ret) {
-			pr_err(
-				"Couldn't change link %s->%s to %s. Error %d\n",
-				source->name, sink->name,
-				flags ? "enabled" : "disabled",
-				ret);
-			return ret;
-		} else
-			au0828_isocdbg(
-				"link %s->%s was %s\n",
-				source->name, sink->name,
-				flags ? "ENABLED" : "disabled");
-	}
-#endif
-	return 0;
-}
-
 static int queue_setup(struct vb2_queue *vq,
 		       unsigned int *nbuffers, unsigned int *nplanes,
 		       unsigned int sizes[], void *alloc_ctxs[])
@@ -707,9 +649,6 @@ static int queue_setup(struct vb2_queue *vq,
 		return sizes[0] < size ? -EINVAL : 0;
 	*nplanes = 1;
 	sizes[0] = size;
-
-	au0828_enable_analog_tuner(dev);
-
 	return 0;
 }
 
-- 
2.5.0

[PATCH REBASE 4.5 18/31] media: au0828 change to use Managed Media Controller API

[Shuah Khan]

Change au0828 to use Managed Media Controller API to coordinate
creating/deleting media device on parent usb device it shares
with the snd-usb-audio driver. With this change, au0828 uses
media_device_get_devres() to allocate a new media device devres
or return an existing one, if it finds one.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/usb/au0828/au0828-core.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index d0fb40b..10c50f5 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -135,10 +135,10 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
 {
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	if (dev->media_dev) {
+	if (dev->media_dev &&
+		media_devnode_is_registered(&dev->media_dev->devnode)) {
 		media_device_unregister(dev->media_dev);
 		media_device_cleanup(dev->media_dev);
-		kfree(dev->media_dev);
 		dev->media_dev = NULL;
 	}
 #endif
@@ -224,23 +224,24 @@ static int au0828_media_device_init(struct au0828_dev *dev,
 #ifdef CONFIG_MEDIA_CONTROLLER
 	struct media_device *mdev;
 
-	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	mdev = media_device_get_devres(&udev->dev);
 	if (!mdev)
 		return -ENOMEM;
 
-	mdev->dev = &udev->dev;
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		mdev->dev = &udev->dev;
 
-	if (!dev->board.name)
-		strlcpy(mdev->model, "unknown au0828", sizeof(mdev->model));
-	else
-		strlcpy(mdev->model, dev->board.name, sizeof(mdev->model));
-	if (udev->serial)
-		strlcpy(mdev->serial, udev->serial, sizeof(mdev->serial));
-	strcpy(mdev->bus_info, udev->devpath);
-	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
-	mdev->driver_version = LINUX_VERSION_CODE;
+		if (udev->product)
+			strlcpy(mdev->model, udev->product,
+				sizeof(mdev->model));
+		if (udev->serial)
+			strlcpy(mdev->serial, udev->serial,
+				sizeof(mdev->serial));
+		strcpy(mdev->bus_info, udev->devpath);
+		mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
 
-	media_device_init(mdev);
+		media_device_init(mdev);
+	}
 
 	dev->media_dev = mdev;
 #endif
-- 
2.5.0

[PATCH REBASE 4.5 18/31] media: au0828 change to use Managed Media Controller API

[Shuah Khan]

Change au0828 to use Managed Media Controller API to coordinate
creating/deleting media device on parent usb device it shares
with the snd-usb-audio driver. With this change, au0828 uses
media_device_get_devres() to allocate a new media device devres
or return an existing one, if it finds one.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/usb/au0828/au0828-core.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index d0fb40b..10c50f5 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -135,10 +135,10 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
 {
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	if (dev->media_dev) {
+	if (dev->media_dev &&
+		media_devnode_is_registered(&dev->media_dev->devnode)) {
 		media_device_unregister(dev->media_dev);
 		media_device_cleanup(dev->media_dev);
-		kfree(dev->media_dev);
 		dev->media_dev = NULL;
 	}
 #endif
@@ -224,23 +224,24 @@ static int au0828_media_device_init(struct au0828_dev *dev,
 #ifdef CONFIG_MEDIA_CONTROLLER
 	struct media_device *mdev;
 
-	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	mdev = media_device_get_devres(&udev->dev);
 	if (!mdev)
 		return -ENOMEM;
 
-	mdev->dev = &udev->dev;
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		mdev->dev = &udev->dev;
 
-	if (!dev->board.name)
-		strlcpy(mdev->model, "unknown au0828", sizeof(mdev->model));
-	else
-		strlcpy(mdev->model, dev->board.name, sizeof(mdev->model));
-	if (udev->serial)
-		strlcpy(mdev->serial, udev->serial, sizeof(mdev->serial));
-	strcpy(mdev->bus_info, udev->devpath);
-	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
-	mdev->driver_version = LINUX_VERSION_CODE;
+		if (udev->product)
+			strlcpy(mdev->model, udev->product,
+				sizeof(mdev->model));
+		if (udev->serial)
+			strlcpy(mdev->serial, udev->serial,
+				sizeof(mdev->serial));
+		strcpy(mdev->bus_info, udev->devpath);
+		mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
 
-	media_device_init(mdev);
+		media_device_init(mdev);
+	}
 
 	dev->media_dev = mdev;
 #endif
-- 
2.5.0

[PATCH REBASE 4.5 22/31] media: dvb-core create tuner to demod pad link in disabled state

[Shuah Khan]

Create tuner to demod pad link in disabled state to help avoid
disable step when tuner resource is requested by video or audio.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/dvb-core/dvbdev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index 560450a..189f85e 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -659,12 +659,12 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
 	}
 
 	if (ntuner && ndemod) {
+		/* create tuner to demod link deactivated */
 		ret = media_create_pad_links(mdev,
 					     MEDIA_ENT_F_TUNER,
 					     tuner, TUNER_PAD_IF_OUTPUT,
 					     MEDIA_ENT_F_DTV_DEMOD,
-					     demod, 0, MEDIA_LNK_FL_ENABLED,
-					     false);
+					     demod, 0, 0, false);
 		if (ret)
 			return ret;
 	}
-- 
2.5.0

[PATCH REBASE 4.5 22/31] media: dvb-core create tuner to demod pad link in disabled state

[Shuah Khan]

Create tuner to demod pad link in disabled state to help avoid
disable step when tuner resource is requested by video or audio.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/dvb-core/dvbdev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index 560450a..189f85e 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -659,12 +659,12 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
 	}
 
 	if (ntuner && ndemod) {
+		/* create tuner to demod link deactivated */
 		ret = media_create_pad_links(mdev,
 					     MEDIA_ENT_F_TUNER,
 					     tuner, TUNER_PAD_IF_OUTPUT,
 					     MEDIA_ENT_F_DTV_DEMOD,
-					     demod, 0, MEDIA_LNK_FL_ENABLED,
-					     false);
+					     demod, 0, 0, false);
 		if (ret)
 			return ret;
 	}
-- 
2.5.0

[PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Shuah Khan]

Change ALSA driver to use Managed Media Managed Controller
API to share tuner with DVB and V4L2 drivers that control
AU0828 media device.  Media device is created based on a
newly added field value in the struct snd_usb_audio_quirk.
Using this approach, the media controller API usage can be
added for a specific device. In this patch, Media Controller
API is enabled for AU0828 hw. snd_usb_create_quirk() will
check this new field, if set will create a media device using
media_device_get_devres() interface.

media_device_get_devres() will allocate a new media device
devres or return an existing one, if it finds one.

During probe, media usb driver could have created the media
device devres. It will then initialze (if necessary) and
register the media device if it isn't already initialized
and registered. Media device unregister is done from
usb_audio_disconnect().

During probe, media usb driver could have created the
media device devres. It will then register the media
device if it isn't already registered. Media device
unregister is done from usb_audio_disconnect().

New structure media_ctl is added to group the new
fields to support media entity and links. This new
structure is added to struct snd_usb_substream.

A new entity_notify hook and a new ALSA capture media
entity are registered from snd_usb_pcm_open() after
setting up hardware information for the PCM device.

When a new entity is registered, Media Controller API
interface media_device_register_entity() invokes all
registered entity_notify hooks for the media device.
ALSA entity_notify hook parses all the entity list to
find a link from decoder it ALSA entity. This indicates
that the bridge driver created a link from decoder to
ALSA capture entity.

ALSA will attempt to enable the tuner to link the tuner
to the decoder calling enable_source handler if one is
provided by the bridge driver prior to starting Media
pipeline from snd_usb_hw_params(). If enable_source returns
with tuner busy condition, then snd_usb_hw_params() will fail
with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 sound/usb/Kconfig        |   4 ++
 sound/usb/Makefile       |   2 +
 sound/usb/card.c         |   7 ++
 sound/usb/card.h         |   1 +
 sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
 sound/usb/media.h        |  55 ++++++++++++++
 sound/usb/pcm.c          |  28 ++++++--
 sound/usb/quirks-table.h |   1 +
 sound/usb/quirks.c       |   5 ++
 sound/usb/stream.c       |   2 +
 sound/usb/usbaudio.h     |   1 +
 11 files changed, 285 insertions(+), 5 deletions(-)
 create mode 100644 sound/usb/media.c
 create mode 100644 sound/usb/media.h

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index a452ad7..1a71d93 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -15,6 +15,7 @@ config SND_USB_AUDIO
 	select SND_RAWMIDI
 	select SND_PCM
 	select BITREVERSE
+	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
 	help
 	  Say Y here to include support for USB audio and USB MIDI
 	  devices.
@@ -22,6 +23,9 @@ config SND_USB_AUDIO
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-usb-audio.
 
+config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+	bool
+
 config SND_USB_UA101
 	tristate "Edirol UA-101/UA-1000 driver"
 	select SND_PCM
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 2d2d122..8dca3c4 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
 			quirks.o \
 			stream.o
 
+snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
+
 snd-usbmidi-lib-objs := midi.o
 
 # Toplevel Module Dependency
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1f09d95..3b226ed 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -66,6 +66,7 @@
 #include "format.h"
 #include "power.h"
 #include "stream.h"
+#include "media.h"
 
 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
 MODULE_DESCRIPTION("USB Audio");
@@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
 		list_for_each_entry(mixer, &chip->mixer_list, list) {
 			snd_usb_mixer_disconnect(mixer);
 		}
+		/*
+		 * Nice to check quirk && quirk->media_device
+		 * need some special handlings. Doesn't look like
+		 * we have access to quirk here
+		*/
+		media_device_delete(intf);
 	}
 
 	chip->num_interfaces--;
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 71778ca..c15a03c 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -156,6 +156,7 @@ struct snd_usb_substream {
 	} dsd_dop;
 
 	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
+	void *media_ctl;
 };
 
 struct snd_usb_stream {
diff --git a/sound/usb/media.c b/sound/usb/media.c
new file mode 100644
index 0000000..0987f40
--- /dev/null
+++ b/sound/usb/media.c
@@ -0,0 +1,184 @@
+/*
+ * media.c - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on existing quirks framework. Using this
+ * approach, the media controller API usage can be added for
+ * a specific device.
+*/
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "media.h"
+
+int media_device_create(struct snd_usb_audio *chip,
+			struct usb_interface *iface)
+{
+	struct media_device *mdev;
+	struct usb_device *usbdev = interface_to_usbdev(iface);
+	int ret;
+
+	mdev = media_device_get_devres(&usbdev->dev);
+	if (!mdev)
+		return -ENOMEM;
+	if (!mdev->dev) {
+		/* register media device */
+		mdev->dev = &usbdev->dev;
+		if (usbdev->product)
+			strlcpy(mdev->model, usbdev->product,
+				sizeof(mdev->model));
+		if (usbdev->serial)
+			strlcpy(mdev->serial, usbdev->serial,
+				sizeof(mdev->serial));
+		strcpy(mdev->bus_info, usbdev->devpath);
+		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
+		media_device_init(mdev);
+	}
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		ret = media_device_register(mdev);
+		if (ret) {
+			dev_err(&usbdev->dev,
+				"Couldn't register media device. Error: %d\n",
+				ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+void media_device_delete(struct usb_interface *iface)
+{
+	struct media_device *mdev;
+	struct usb_device *usbdev = interface_to_usbdev(iface);
+
+	mdev = media_device_find_devres(&usbdev->dev);
+	if (mdev && media_devnode_is_registered(&mdev->devnode))
+		media_device_unregister(mdev);
+}
+
+static int media_enable_source(struct media_ctl *mctl)
+{
+	if (mctl && mctl->media_dev->enable_source)
+		return mctl->media_dev->enable_source(&mctl->media_entity,
+						      &mctl->media_pipe);
+	return 0;
+}
+
+static void media_disable_source(struct media_ctl *mctl)
+{
+	if (mctl && mctl->media_dev->disable_source)
+		mctl->media_dev->disable_source(&mctl->media_entity);
+}
+
+int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+			int stream)
+{
+	struct media_device *mdev;
+	struct media_ctl *mctl;
+	struct device *pcm_dev = &pcm->streams[stream].dev;
+	u32 intf_type;
+	int ret = 0;
+
+	mdev = media_device_find_devres(&subs->dev->dev);
+	if (!mdev)
+		return -ENODEV;
+
+	if (subs->media_ctl)
+		return 0;
+
+	/* allocate media_ctl */
+	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
+	if (!mctl)
+		return -ENOMEM;
+
+	mctl->media_dev = mdev;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
+	} else {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
+	}
+	mctl->media_entity.name = pcm->name;
+	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
+	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
+	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
+	media_entity_pads_init(&mctl->media_entity, 1, &mctl->media_pad);
+	ret =  media_device_register_entity(mctl->media_dev,
+					    &mctl->media_entity);
+	if (ret) {
+		kfree(mctl);
+		return ret;
+	}
+	mctl->intf_devnode = media_devnode_create(mdev, intf_type, 0,
+						  MAJOR(pcm_dev->devt),
+						  MINOR(pcm_dev->devt));
+	if (!mctl->intf_devnode) {
+		media_device_unregister_entity(&mctl->media_entity);
+		kfree(mctl);
+		return -ENOMEM;
+	}
+	mctl->intf_link = media_create_intf_link(&mctl->media_entity,
+						 &mctl->intf_devnode->intf,
+						 MEDIA_LNK_FL_ENABLED);
+	if (!mctl->intf_link) {
+		media_devnode_remove(mctl->intf_devnode);
+		media_device_unregister_entity(&mctl->media_entity);
+		kfree(mctl);
+		return -ENOMEM;
+	}
+	subs->media_ctl = mctl;
+	return 0;
+}
+
+void media_stream_delete(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl && mctl->media_dev) {
+		struct media_device *mdev;
+
+		mdev = media_device_find_devres(&subs->dev->dev);
+		if (mdev) {
+			media_devnode_remove(mctl->intf_devnode);
+			media_device_unregister_entity(&mctl->media_entity);
+			media_entity_cleanup(&mctl->media_entity);
+		}
+		kfree(mctl);
+		subs->media_ctl = NULL;
+	}
+}
+
+int media_start_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl)
+		return media_enable_source(mctl);
+	return 0;
+}
+
+void media_stop_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl)
+		media_disable_source(mctl);
+}
diff --git a/sound/usb/media.h b/sound/usb/media.h
new file mode 100644
index 0000000..698c2a4
--- /dev/null
+++ b/sound/usb/media.h
@@ -0,0 +1,55 @@
+/*
+ * media.h - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on existing quirks framework. Using this
+ * approach, the media controller API usage can be added for
+ * a specific device.
+*/
+#ifndef __MEDIA_H
+
+#ifdef CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+
+#include <media/media-device.h>
+#include <media/media-entity.h>
+
+struct media_ctl {
+	struct media_device *media_dev;
+	struct media_entity media_entity;
+	struct media_intf_devnode *intf_devnode;
+	struct media_link *intf_link;
+	struct media_pad media_pad;
+	struct media_pipeline media_pipe;
+};
+
+int media_device_create(struct snd_usb_audio *chip,
+			struct usb_interface *iface);
+void media_device_delete(struct usb_interface *iface);
+int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+			int stream);
+void media_stream_delete(struct snd_usb_substream *subs);
+int media_start_pipeline(struct snd_usb_substream *subs);
+void media_stop_pipeline(struct snd_usb_substream *subs);
+#else
+static inline int media_device_create(struct snd_usb_audio *chip,
+				      struct usb_interface *iface)
+						{ return 0; }
+static inline void media_device_delete(struct usb_interface *iface) { }
+static inline int media_stream_init(struct snd_usb_substream *subs,
+					struct snd_pcm *pcm, int stream)
+						{ return 0; }
+static inline void media_stream_delete(struct snd_usb_substream *subs) { }
+static inline int media_start_pipeline(struct snd_usb_substream *subs)
+					{ return 0; }
+static inline void media_stop_pipeline(struct snd_usb_substream *subs) { }
+#endif
+#endif /* __MEDIA_H */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9245f52..c3b8486 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -35,6 +35,7 @@
 #include "pcm.h"
 #include "clock.h"
 #include "power.h"
+#include "media.h"
 
 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
@@ -715,10 +716,14 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	struct audioformat *fmt;
 	int ret;
 
+	ret = media_start_pipeline(subs);
+	if (ret)
+		return ret;
+
 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
 					       params_buffer_bytes(hw_params));
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 
 	subs->pcm_format = params_format(hw_params);
 	subs->period_bytes = params_period_bytes(hw_params);
@@ -732,22 +737,27 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		dev_dbg(&subs->dev->dev,
 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
 			   subs->pcm_format, subs->cur_rate, subs->channels);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_ret;
 	}
 
 	ret = snd_usb_lock_shutdown(subs->stream->chip);
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 	ret = set_format(subs, fmt);
 	snd_usb_unlock_shutdown(subs->stream->chip);
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 
 	subs->interface = fmt->iface;
 	subs->altset_idx = fmt->altset_idx;
 	subs->need_setup_ep = true;
 
 	return 0;
+
+err_ret:
+	media_stop_pipeline(subs);
+	return ret;
 }
 
 /*
@@ -759,6 +769,7 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_usb_substream *subs = substream->runtime->private_data;
 
+	media_stop_pipeline(subs);
 	subs->cur_audiofmt = NULL;
 	subs->cur_rate = 0;
 	subs->period_bytes = 0;
@@ -1219,6 +1230,7 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_usb_substream *subs = &as->substream[direction];
+	int ret;
 
 	subs->interface = -1;
 	subs->altset_idx = 0;
@@ -1232,7 +1244,12 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
 	subs->dsd_dop.channel = 0;
 	subs->dsd_dop.marker = 1;
 
-	return setup_hw_info(runtime, subs);
+	ret = setup_hw_info(runtime, subs);
+	if (ret == 0)
+		ret = media_stream_init(subs, as->pcm, direction);
+	if (ret)
+		snd_usb_autosuspend(subs->stream->chip);
+	return ret;
 }
 
 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
@@ -1241,6 +1258,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
 	struct snd_usb_substream *subs = &as->substream[direction];
 
 	stop_endpoints(subs, true);
+	media_stop_pipeline(subs);
 
 	if (subs->interface >= 0 &&
 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index c60a776..9d087b1 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2886,6 +2886,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 		.product_name = pname, \
 		.ifnum = QUIRK_ANY_INTERFACE, \
 		.type = QUIRK_AUDIO_ALIGN_TRANSFER, \
+		.media_device = 1, \
 	} \
 }
 
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 23ea6d8..fbf056a 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -36,6 +36,7 @@
 #include "pcm.h"
 #include "clock.h"
 #include "stream.h"
+#include "media.h"
 
 /*
  * handle the quirks for the contained interfaces
@@ -546,6 +547,10 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip,
 		[QUIRK_AUDIO_STANDARD_MIXER] = create_standard_mixer_quirk,
 	};
 
+	if (quirk->media_device) {
+		/* don't want to fail when media_device_create() fails */
+		media_device_create(chip, iface);
+	}
 	if (quirk->type < QUIRK_TYPE_COUNT) {
 		return quirk_funcs[quirk->type](chip, iface, driver, quirk);
 	} else {
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index c4dc577..6c7f5c1 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -36,6 +36,7 @@
 #include "format.h"
 #include "clock.h"
 #include "stream.h"
+#include "media.h"
 
 /*
  * free a substream
@@ -52,6 +53,7 @@ static void free_substream(struct snd_usb_substream *subs)
 		kfree(fp);
 	}
 	kfree(subs->rate_list.list);
+	media_stream_delete(subs);
 }
 
 
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index b665d85..335f48c 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -110,6 +110,7 @@ struct snd_usb_audio_quirk {
 	const char *product_name;
 	int16_t ifnum;
 	uint16_t type;
+	bool media_device;
 	const void *data;
 };
 
-- 
2.5.0

[PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Shuah Khan]

Change ALSA driver to use Managed Media Managed Controller
API to share tuner with DVB and V4L2 drivers that control
AU0828 media device.  Media device is created based on a
newly added field value in the struct snd_usb_audio_quirk.
Using this approach, the media controller API usage can be
added for a specific device. In this patch, Media Controller
API is enabled for AU0828 hw. snd_usb_create_quirk() will
check this new field, if set will create a media device using
media_device_get_devres() interface.

media_device_get_devres() will allocate a new media device
devres or return an existing one, if it finds one.

During probe, media usb driver could have created the media
device devres. It will then initialze (if necessary) and
register the media device if it isn't already initialized
and registered. Media device unregister is done from
usb_audio_disconnect().

During probe, media usb driver could have created the
media device devres. It will then register the media
device if it isn't already registered. Media device
unregister is done from usb_audio_disconnect().

New structure media_ctl is added to group the new
fields to support media entity and links. This new
structure is added to struct snd_usb_substream.

A new entity_notify hook and a new ALSA capture media
entity are registered from snd_usb_pcm_open() after
setting up hardware information for the PCM device.

When a new entity is registered, Media Controller API
interface media_device_register_entity() invokes all
registered entity_notify hooks for the media device.
ALSA entity_notify hook parses all the entity list to
find a link from decoder it ALSA entity. This indicates
that the bridge driver created a link from decoder to
ALSA capture entity.

ALSA will attempt to enable the tuner to link the tuner
to the decoder calling enable_source handler if one is
provided by the bridge driver prior to starting Media
pipeline from snd_usb_hw_params(). If enable_source returns
with tuner busy condition, then snd_usb_hw_params() will fail
with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().

Signed-off-by: Shuah Khan <shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
---
 sound/usb/Kconfig        |   4 ++
 sound/usb/Makefile       |   2 +
 sound/usb/card.c         |   7 ++
 sound/usb/card.h         |   1 +
 sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
 sound/usb/media.h        |  55 ++++++++++++++
 sound/usb/pcm.c          |  28 ++++++--
 sound/usb/quirks-table.h |   1 +
 sound/usb/quirks.c       |   5 ++
 sound/usb/stream.c       |   2 +
 sound/usb/usbaudio.h     |   1 +
 11 files changed, 285 insertions(+), 5 deletions(-)
 create mode 100644 sound/usb/media.c
 create mode 100644 sound/usb/media.h

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index a452ad7..1a71d93 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -15,6 +15,7 @@ config SND_USB_AUDIO
 	select SND_RAWMIDI
 	select SND_PCM
 	select BITREVERSE
+	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
 	help
 	  Say Y here to include support for USB audio and USB MIDI
 	  devices.
@@ -22,6 +23,9 @@ config SND_USB_AUDIO
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-usb-audio.
 
+config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+	bool
+
 config SND_USB_UA101
 	tristate "Edirol UA-101/UA-1000 driver"
 	select SND_PCM
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 2d2d122..8dca3c4 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
 			quirks.o \
 			stream.o
 
+snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
+
 snd-usbmidi-lib-objs := midi.o
 
 # Toplevel Module Dependency
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1f09d95..3b226ed 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -66,6 +66,7 @@
 #include "format.h"
 #include "power.h"
 #include "stream.h"
+#include "media.h"
 
 MODULE_AUTHOR("Takashi Iwai <tiwai-l3A5Bk7waGM@public.gmane.org>");
 MODULE_DESCRIPTION("USB Audio");
@@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
 		list_for_each_entry(mixer, &chip->mixer_list, list) {
 			snd_usb_mixer_disconnect(mixer);
 		}
+		/*
+		 * Nice to check quirk && quirk->media_device
+		 * need some special handlings. Doesn't look like
+		 * we have access to quirk here
+		*/
+		media_device_delete(intf);
 	}
 
 	chip->num_interfaces--;
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 71778ca..c15a03c 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -156,6 +156,7 @@ struct snd_usb_substream {
 	} dsd_dop;
 
 	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
+	void *media_ctl;
 };
 
 struct snd_usb_stream {
diff --git a/sound/usb/media.c b/sound/usb/media.c
new file mode 100644
index 0000000..0987f40
--- /dev/null
+++ b/sound/usb/media.c
@@ -0,0 +1,184 @@
+/*
+ * media.c - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2015 Shuah Khan <shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on existing quirks framework. Using this
+ * approach, the media controller API usage can be added for
+ * a specific device.
+*/
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "media.h"
+
+int media_device_create(struct snd_usb_audio *chip,
+			struct usb_interface *iface)
+{
+	struct media_device *mdev;
+	struct usb_device *usbdev = interface_to_usbdev(iface);
+	int ret;
+
+	mdev = media_device_get_devres(&usbdev->dev);
+	if (!mdev)
+		return -ENOMEM;
+	if (!mdev->dev) {
+		/* register media device */
+		mdev->dev = &usbdev->dev;
+		if (usbdev->product)
+			strlcpy(mdev->model, usbdev->product,
+				sizeof(mdev->model));
+		if (usbdev->serial)
+			strlcpy(mdev->serial, usbdev->serial,
+				sizeof(mdev->serial));
+		strcpy(mdev->bus_info, usbdev->devpath);
+		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
+		media_device_init(mdev);
+	}
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		ret = media_device_register(mdev);
+		if (ret) {
+			dev_err(&usbdev->dev,
+				"Couldn't register media device. Error: %d\n",
+				ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+void media_device_delete(struct usb_interface *iface)
+{
+	struct media_device *mdev;
+	struct usb_device *usbdev = interface_to_usbdev(iface);
+
+	mdev = media_device_find_devres(&usbdev->dev);
+	if (mdev && media_devnode_is_registered(&mdev->devnode))
+		media_device_unregister(mdev);
+}
+
+static int media_enable_source(struct media_ctl *mctl)
+{
+	if (mctl && mctl->media_dev->enable_source)
+		return mctl->media_dev->enable_source(&mctl->media_entity,
+						      &mctl->media_pipe);
+	return 0;
+}
+
+static void media_disable_source(struct media_ctl *mctl)
+{
+	if (mctl && mctl->media_dev->disable_source)
+		mctl->media_dev->disable_source(&mctl->media_entity);
+}
+
+int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+			int stream)
+{
+	struct media_device *mdev;
+	struct media_ctl *mctl;
+	struct device *pcm_dev = &pcm->streams[stream].dev;
+	u32 intf_type;
+	int ret = 0;
+
+	mdev = media_device_find_devres(&subs->dev->dev);
+	if (!mdev)
+		return -ENODEV;
+
+	if (subs->media_ctl)
+		return 0;
+
+	/* allocate media_ctl */
+	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
+	if (!mctl)
+		return -ENOMEM;
+
+	mctl->media_dev = mdev;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
+	} else {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
+	}
+	mctl->media_entity.name = pcm->name;
+	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
+	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
+	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
+	media_entity_pads_init(&mctl->media_entity, 1, &mctl->media_pad);
+	ret =  media_device_register_entity(mctl->media_dev,
+					    &mctl->media_entity);
+	if (ret) {
+		kfree(mctl);
+		return ret;
+	}
+	mctl->intf_devnode = media_devnode_create(mdev, intf_type, 0,
+						  MAJOR(pcm_dev->devt),
+						  MINOR(pcm_dev->devt));
+	if (!mctl->intf_devnode) {
+		media_device_unregister_entity(&mctl->media_entity);
+		kfree(mctl);
+		return -ENOMEM;
+	}
+	mctl->intf_link = media_create_intf_link(&mctl->media_entity,
+						 &mctl->intf_devnode->intf,
+						 MEDIA_LNK_FL_ENABLED);
+	if (!mctl->intf_link) {
+		media_devnode_remove(mctl->intf_devnode);
+		media_device_unregister_entity(&mctl->media_entity);
+		kfree(mctl);
+		return -ENOMEM;
+	}
+	subs->media_ctl = mctl;
+	return 0;
+}
+
+void media_stream_delete(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl && mctl->media_dev) {
+		struct media_device *mdev;
+
+		mdev = media_device_find_devres(&subs->dev->dev);
+		if (mdev) {
+			media_devnode_remove(mctl->intf_devnode);
+			media_device_unregister_entity(&mctl->media_entity);
+			media_entity_cleanup(&mctl->media_entity);
+		}
+		kfree(mctl);
+		subs->media_ctl = NULL;
+	}
+}
+
+int media_start_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl)
+		return media_enable_source(mctl);
+	return 0;
+}
+
+void media_stop_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl)
+		media_disable_source(mctl);
+}
diff --git a/sound/usb/media.h b/sound/usb/media.h
new file mode 100644
index 0000000..698c2a4
--- /dev/null
+++ b/sound/usb/media.h
@@ -0,0 +1,55 @@
+/*
+ * media.h - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2015 Shuah Khan <shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on existing quirks framework. Using this
+ * approach, the media controller API usage can be added for
+ * a specific device.
+*/
+#ifndef __MEDIA_H
+
+#ifdef CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+
+#include <media/media-device.h>
+#include <media/media-entity.h>
+
+struct media_ctl {
+	struct media_device *media_dev;
+	struct media_entity media_entity;
+	struct media_intf_devnode *intf_devnode;
+	struct media_link *intf_link;
+	struct media_pad media_pad;
+	struct media_pipeline media_pipe;
+};
+
+int media_device_create(struct snd_usb_audio *chip,
+			struct usb_interface *iface);
+void media_device_delete(struct usb_interface *iface);
+int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+			int stream);
+void media_stream_delete(struct snd_usb_substream *subs);
+int media_start_pipeline(struct snd_usb_substream *subs);
+void media_stop_pipeline(struct snd_usb_substream *subs);
+#else
+static inline int media_device_create(struct snd_usb_audio *chip,
+				      struct usb_interface *iface)
+						{ return 0; }
+static inline void media_device_delete(struct usb_interface *iface) { }
+static inline int media_stream_init(struct snd_usb_substream *subs,
+					struct snd_pcm *pcm, int stream)
+						{ return 0; }
+static inline void media_stream_delete(struct snd_usb_substream *subs) { }
+static inline int media_start_pipeline(struct snd_usb_substream *subs)
+					{ return 0; }
+static inline void media_stop_pipeline(struct snd_usb_substream *subs) { }
+#endif
+#endif /* __MEDIA_H */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9245f52..c3b8486 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -35,6 +35,7 @@
 #include "pcm.h"
 #include "clock.h"
 #include "power.h"
+#include "media.h"
 
 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
@@ -715,10 +716,14 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	struct audioformat *fmt;
 	int ret;
 
+	ret = media_start_pipeline(subs);
+	if (ret)
+		return ret;
+
 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
 					       params_buffer_bytes(hw_params));
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 
 	subs->pcm_format = params_format(hw_params);
 	subs->period_bytes = params_period_bytes(hw_params);
@@ -732,22 +737,27 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		dev_dbg(&subs->dev->dev,
 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
 			   subs->pcm_format, subs->cur_rate, subs->channels);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_ret;
 	}
 
 	ret = snd_usb_lock_shutdown(subs->stream->chip);
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 	ret = set_format(subs, fmt);
 	snd_usb_unlock_shutdown(subs->stream->chip);
 	if (ret < 0)
-		return ret;
+		goto err_ret;
 
 	subs->interface = fmt->iface;
 	subs->altset_idx = fmt->altset_idx;
 	subs->need_setup_ep = true;
 
 	return 0;
+
+err_ret:
+	media_stop_pipeline(subs);
+	return ret;
 }
 
 /*
@@ -759,6 +769,7 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_usb_substream *subs = substream->runtime->private_data;
 
+	media_stop_pipeline(subs);
 	subs->cur_audiofmt = NULL;
 	subs->cur_rate = 0;
 	subs->period_bytes = 0;
@@ -1219,6 +1230,7 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_usb_substream *subs = &as->substream[direction];
+	int ret;
 
 	subs->interface = -1;
 	subs->altset_idx = 0;
@@ -1232,7 +1244,12 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
 	subs->dsd_dop.channel = 0;
 	subs->dsd_dop.marker = 1;
 
-	return setup_hw_info(runtime, subs);
+	ret = setup_hw_info(runtime, subs);
+	if (ret == 0)
+		ret = media_stream_init(subs, as->pcm, direction);
+	if (ret)
+		snd_usb_autosuspend(subs->stream->chip);
+	return ret;
 }
 
 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
@@ -1241,6 +1258,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
 	struct snd_usb_substream *subs = &as->substream[direction];
 
 	stop_endpoints(subs, true);
+	media_stop_pipeline(subs);
 
 	if (subs->interface >= 0 &&
 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index c60a776..9d087b1 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2886,6 +2886,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 		.product_name = pname, \
 		.ifnum = QUIRK_ANY_INTERFACE, \
 		.type = QUIRK_AUDIO_ALIGN_TRANSFER, \
+		.media_device = 1, \
 	} \
 }
 
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 23ea6d8..fbf056a 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -36,6 +36,7 @@
 #include "pcm.h"
 #include "clock.h"
 #include "stream.h"
+#include "media.h"
 
 /*
  * handle the quirks for the contained interfaces
@@ -546,6 +547,10 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip,
 		[QUIRK_AUDIO_STANDARD_MIXER] = create_standard_mixer_quirk,
 	};
 
+	if (quirk->media_device) {
+		/* don't want to fail when media_device_create() fails */
+		media_device_create(chip, iface);
+	}
 	if (quirk->type < QUIRK_TYPE_COUNT) {
 		return quirk_funcs[quirk->type](chip, iface, driver, quirk);
 	} else {
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index c4dc577..6c7f5c1 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -36,6 +36,7 @@
 #include "format.h"
 #include "clock.h"
 #include "stream.h"
+#include "media.h"
 
 /*
  * free a substream
@@ -52,6 +53,7 @@ static void free_substream(struct snd_usb_substream *subs)
 		kfree(fp);
 	}
 	kfree(subs->rate_list.list);
+	media_stream_delete(subs);
 }
 
 
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index b665d85..335f48c 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -110,6 +110,7 @@ struct snd_usb_audio_quirk {
 	const char *product_name;
 	int16_t ifnum;
 	uint16_t type;
+	bool media_device;
 	const void *data;
 };
 
-- 
2.5.0

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

On 01/21/2016 11:09 AM, Shuah Khan wrote:
> Please note that I am sending just the 4 patches that
> changed during series rebase to Linux 4.5. The rebase
> was pain free. media_device_init() type change required
> changes to patches 18 and 26. I re-tested the series
> and everything looks good.
> 
> [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
> [PATCH 18/31] media: au0828 change to use Managed Media Controller API
> [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
> [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
> 
> Links:
> PATCH Series that contains all 31 patches:
> https://lkml.org/lkml/2016/1/6/668
> 
> ALSA patches went through reviews and links
> to PATCH V3 (ALSA):
> https://lkml.org/lkml/2016/1/18/556
> https://lkml.org/lkml/2016/1/18/557
> https://lkml.org/lkml/2016/1/18/558
> 
> Compile warns patches:
> https://lkml.org/lkml/2016/1/19/520
> https://lkml.org/lkml/2016/1/19/518
> https://lkml.org/lkml/2016/1/19/519
> 
> Mauro and Takashi:
> Please let me know if you would rather see the entire
> patch series generated for 4.5-rc1 and sent out in a
> complete series instead of just the rebased patches.
> 

Hi Takashi,

Are you okay with this ALSA patch series?
If so could you please Ack these patches
so they can be pulled into media tree.

Mauro,

Could you please look these over and give
me feedback and let me know if you would
like me to resend all the patches in final
series.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

On 01/21/2016 11:09 AM, Shuah Khan wrote:
> Please note that I am sending just the 4 patches that
> changed during series rebase to Linux 4.5. The rebase
> was pain free. media_device_init() type change required
> changes to patches 18 and 26. I re-tested the series
> and everything looks good.
> 
> [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
> [PATCH 18/31] media: au0828 change to use Managed Media Controller API
> [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
> [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
> 
> Links:
> PATCH Series that contains all 31 patches:
> https://lkml.org/lkml/2016/1/6/668
> 
> ALSA patches went through reviews and links
> to PATCH V3 (ALSA):
> https://lkml.org/lkml/2016/1/18/556
> https://lkml.org/lkml/2016/1/18/557
> https://lkml.org/lkml/2016/1/18/558
> 
> Compile warns patches:
> https://lkml.org/lkml/2016/1/19/520
> https://lkml.org/lkml/2016/1/19/518
> https://lkml.org/lkml/2016/1/19/519
> 
> Mauro and Takashi:
> Please let me know if you would rather see the entire
> patch series generated for 4.5-rc1 and sent out in a
> complete series instead of just the rebased patches.
> 

Hi Takashi,

Are you okay with this ALSA patch series?
If so could you please Ack these patches
so they can be pulled into media tree.

Mauro,

Could you please look these over and give
me feedback and let me know if you would
like me to resend all the patches in final
series.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Takashi Iwai]

On Thu, 28 Jan 2016 15:56:55 +0100,
Shuah Khan wrote:
> 
> On 01/21/2016 11:09 AM, Shuah Khan wrote:
> > Please note that I am sending just the 4 patches that
> > changed during series rebase to Linux 4.5. The rebase
> > was pain free. media_device_init() type change required
> > changes to patches 18 and 26. I re-tested the series
> > and everything looks good.
> > 
> > [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
> > [PATCH 18/31] media: au0828 change to use Managed Media Controller API
> > [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
> > [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
> > 
> > Links:
> > PATCH Series that contains all 31 patches:
> > https://lkml.org/lkml/2016/1/6/668
> > 
> > ALSA patches went through reviews and links
> > to PATCH V3 (ALSA):
> > https://lkml.org/lkml/2016/1/18/556
> > https://lkml.org/lkml/2016/1/18/557
> > https://lkml.org/lkml/2016/1/18/558
> > 
> > Compile warns patches:
> > https://lkml.org/lkml/2016/1/19/520
> > https://lkml.org/lkml/2016/1/19/518
> > https://lkml.org/lkml/2016/1/19/519
> > 
> > Mauro and Takashi:
> > Please let me know if you would rather see the entire
> > patch series generated for 4.5-rc1 and sent out in a
> > complete series instead of just the rebased patches.
> > 
> 
> Hi Takashi,
> 
> Are you okay with this ALSA patch series?

Sorry, too little time until now.
I know there are still a few potential problems.  Will do detailed
reviews later.


Takashi

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Takashi Iwai]

On Thu, 28 Jan 2016 15:56:55 +0100,
Shuah Khan wrote:
> 
> On 01/21/2016 11:09 AM, Shuah Khan wrote:
> > Please note that I am sending just the 4 patches that
> > changed during series rebase to Linux 4.5. The rebase
> > was pain free. media_device_init() type change required
> > changes to patches 18 and 26. I re-tested the series
> > and everything looks good.
> > 
> > [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
> > [PATCH 18/31] media: au0828 change to use Managed Media Controller API
> > [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
> > [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
> > 
> > Links:
> > PATCH Series that contains all 31 patches:
> > https://lkml.org/lkml/2016/1/6/668
> > 
> > ALSA patches went through reviews and links
> > to PATCH V3 (ALSA):
> > https://lkml.org/lkml/2016/1/18/556
> > https://lkml.org/lkml/2016/1/18/557
> > https://lkml.org/lkml/2016/1/18/558
> > 
> > Compile warns patches:
> > https://lkml.org/lkml/2016/1/19/520
> > https://lkml.org/lkml/2016/1/19/518
> > https://lkml.org/lkml/2016/1/19/519
> > 
> > Mauro and Takashi:
> > Please let me know if you would rather see the entire
> > patch series generated for 4.5-rc1 and sent out in a
> > complete series instead of just the rebased patches.
> > 
> 
> Hi Takashi,
> 
> Are you okay with this ALSA patch series?

Sorry, too little time until now.
I know there are still a few potential problems.  Will do detailed
reviews later.


Takashi

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

On 01/28/2016 08:18 AM, Takashi Iwai wrote:
> On Thu, 28 Jan 2016 15:56:55 +0100,
> Shuah Khan wrote:
>>
>> On 01/21/2016 11:09 AM, Shuah Khan wrote:
>>> Please note that I am sending just the 4 patches that
>>> changed during series rebase to Linux 4.5. The rebase
>>> was pain free. media_device_init() type change required
>>> changes to patches 18 and 26. I re-tested the series
>>> and everything looks good.
>>>
>>> [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
>>> [PATCH 18/31] media: au0828 change to use Managed Media Controller API
>>> [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
>>> [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
>>>
>>> Links:
>>> PATCH Series that contains all 31 patches:
>>> https://lkml.org/lkml/2016/1/6/668
>>>
>>> ALSA patches went through reviews and links
>>> to PATCH V3 (ALSA):
>>> https://lkml.org/lkml/2016/1/18/556
>>> https://lkml.org/lkml/2016/1/18/557
>>> https://lkml.org/lkml/2016/1/18/558
>>>
>>> Compile warns patches:
>>> https://lkml.org/lkml/2016/1/19/520
>>> https://lkml.org/lkml/2016/1/19/518
>>> https://lkml.org/lkml/2016/1/19/519
>>>
>>> Mauro and Takashi:
>>> Please let me know if you would rather see the entire
>>> patch series generated for 4.5-rc1 and sent out in a
>>> complete series instead of just the rebased patches.
>>>
>>
>> Hi Takashi,
>>
>> Are you okay with this ALSA patch series?
> 
> Sorry, too little time until now.
> I know there are still a few potential problems.  Will do detailed
> reviews later.
> 

I would like to wrap this up and hopefully get this
into 4.6. Please let me know if you will be able to
review in time for that.

I have a few comments work on from Mauro and would
like to address comments from you as well at the same
time.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 00/31] Sharing media resources across ALSA and au0828 drivers

[Shuah Khan]

On 01/28/2016 08:18 AM, Takashi Iwai wrote:
> On Thu, 28 Jan 2016 15:56:55 +0100,
> Shuah Khan wrote:
>>
>> On 01/21/2016 11:09 AM, Shuah Khan wrote:
>>> Please note that I am sending just the 4 patches that
>>> changed during series rebase to Linux 4.5. The rebase
>>> was pain free. media_device_init() type change required
>>> changes to patches 18 and 26. I re-tested the series
>>> and everything looks good.
>>>
>>> [PATCH 16/31] media: au0828 video remove au0828_enable_analog_tuner()
>>> [PATCH 18/31] media: au0828 change to use Managed Media Controller API
>>> [PATCH 22/31] media: dvb-core create tuner to demod pad link in disabled state
>>> [PATCH v3 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API
>>>
>>> Links:
>>> PATCH Series that contains all 31 patches:
>>> https://lkml.org/lkml/2016/1/6/668
>>>
>>> ALSA patches went through reviews and links
>>> to PATCH V3 (ALSA):
>>> https://lkml.org/lkml/2016/1/18/556
>>> https://lkml.org/lkml/2016/1/18/557
>>> https://lkml.org/lkml/2016/1/18/558
>>>
>>> Compile warns patches:
>>> https://lkml.org/lkml/2016/1/19/520
>>> https://lkml.org/lkml/2016/1/19/518
>>> https://lkml.org/lkml/2016/1/19/519
>>>
>>> Mauro and Takashi:
>>> Please let me know if you would rather see the entire
>>> patch series generated for 4.5-rc1 and sent out in a
>>> complete series instead of just the rebased patches.
>>>
>>
>> Hi Takashi,
>>
>> Are you okay with this ALSA patch series?
> 
> Sorry, too little time until now.
> I know there are still a few potential problems.  Will do detailed
> reviews later.
> 

I would like to wrap this up and hopefully get this
into 4.6. Please let me know if you will be able to
review in time for that.

I have a few comments work on from Mauro and would
like to address comments from you as well at the same
time.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Takashi Iwai]

On Thu, 21 Jan 2016 19:09:50 +0100,
Shuah Khan wrote:
> 
> Change ALSA driver to use Managed Media Managed Controller
> API to share tuner with DVB and V4L2 drivers that control
> AU0828 media device.  Media device is created based on a
> newly added field value in the struct snd_usb_audio_quirk.
> Using this approach, the media controller API usage can be
> added for a specific device. In this patch, Media Controller
> API is enabled for AU0828 hw. snd_usb_create_quirk() will
> check this new field, if set will create a media device using
> media_device_get_devres() interface.
> 
> media_device_get_devres() will allocate a new media device
> devres or return an existing one, if it finds one.
> 
> During probe, media usb driver could have created the media
> device devres. It will then initialze (if necessary) and
> register the media device if it isn't already initialized
> and registered. Media device unregister is done from
> usb_audio_disconnect().
> 
> During probe, media usb driver could have created the
> media device devres. It will then register the media
> device if it isn't already registered. Media device
> unregister is done from usb_audio_disconnect().
> 
> New structure media_ctl is added to group the new
> fields to support media entity and links. This new
> structure is added to struct snd_usb_substream.
> 
> A new entity_notify hook and a new ALSA capture media
> entity are registered from snd_usb_pcm_open() after
> setting up hardware information for the PCM device.
> 
> When a new entity is registered, Media Controller API
> interface media_device_register_entity() invokes all
> registered entity_notify hooks for the media device.
> ALSA entity_notify hook parses all the entity list to
> find a link from decoder it ALSA entity. This indicates
> that the bridge driver created a link from decoder to
> ALSA capture entity.
> 
> ALSA will attempt to enable the tuner to link the tuner
> to the decoder calling enable_source handler if one is
> provided by the bridge driver prior to starting Media
> pipeline from snd_usb_hw_params(). If enable_source returns
> with tuner busy condition, then snd_usb_hw_params() will fail
> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
> 
> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
> ---
>  sound/usb/Kconfig        |   4 ++
>  sound/usb/Makefile       |   2 +
>  sound/usb/card.c         |   7 ++
>  sound/usb/card.h         |   1 +
>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
>  sound/usb/media.h        |  55 ++++++++++++++
>  sound/usb/pcm.c          |  28 ++++++--
>  sound/usb/quirks-table.h |   1 +
>  sound/usb/quirks.c       |   5 ++
>  sound/usb/stream.c       |   2 +
>  sound/usb/usbaudio.h     |   1 +
>  11 files changed, 285 insertions(+), 5 deletions(-)
>  create mode 100644 sound/usb/media.c
>  create mode 100644 sound/usb/media.h
> 
> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
> index a452ad7..1a71d93 100644
> --- a/sound/usb/Kconfig
> +++ b/sound/usb/Kconfig
> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
>  	select SND_RAWMIDI
>  	select SND_PCM
>  	select BITREVERSE
> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
>  	help
>  	  Say Y here to include support for USB audio and USB MIDI
>  	  devices.
> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called snd-usb-audio.
>  
> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
> +	bool
> +
>  config SND_USB_UA101
>  	tristate "Edirol UA-101/UA-1000 driver"
>  	select SND_PCM
> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
> index 2d2d122..8dca3c4 100644
> --- a/sound/usb/Makefile
> +++ b/sound/usb/Makefile
> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
>  			quirks.o \
>  			stream.o
>  
> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
> +
>  snd-usbmidi-lib-objs := midi.o
>  
>  # Toplevel Module Dependency
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index 1f09d95..3b226ed 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -66,6 +66,7 @@
>  #include "format.h"
>  #include "power.h"
>  #include "stream.h"
> +#include "media.h"
>  
>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
>  MODULE_DESCRIPTION("USB Audio");
> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
>  			snd_usb_mixer_disconnect(mixer);
>  		}
> +		/*
> +		 * Nice to check quirk && quirk->media_device
> +		 * need some special handlings. Doesn't look like
> +		 * we have access to quirk here
> +		*/
> +		media_device_delete(intf);
>  	}
>  
>  	chip->num_interfaces--;
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index 71778ca..c15a03c 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -156,6 +156,7 @@ struct snd_usb_substream {
>  	} dsd_dop;
>  
>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
> +	void *media_ctl;
>  };
>  
>  struct snd_usb_stream {
> diff --git a/sound/usb/media.c b/sound/usb/media.c
> new file mode 100644
> index 0000000..0987f40
> --- /dev/null
> +++ b/sound/usb/media.c
> @@ -0,0 +1,184 @@
> +/*
> + * media.c - Media Controller specific ALSA driver code
> + *
> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> + *
> + * This file is released under the GPLv2.
> + */
> +
> +/*
> + * This file adds Media Controller support to ALSA driver
> + * to use the Media Controller API to share tuner with DVB
> + * and V4L2 drivers that control media device. Media device
> + * is created based on existing quirks framework. Using this
> + * approach, the media controller API usage can be added for
> + * a specific device.
> +*/
> +
> +#include <linux/init.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/usb.h>
> +
> +#include <sound/pcm.h>
> +
> +#include "usbaudio.h"
> +#include "card.h"
> +#include "media.h"
> +
> +int media_device_create(struct snd_usb_audio *chip,
> +			struct usb_interface *iface)
> +{
> +	struct media_device *mdev;
> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> +	int ret;
> +
> +	mdev = media_device_get_devres(&usbdev->dev);
> +	if (!mdev)
> +		return -ENOMEM;
> +	if (!mdev->dev) {
> +		/* register media device */
> +		mdev->dev = &usbdev->dev;
> +		if (usbdev->product)
> +			strlcpy(mdev->model, usbdev->product,
> +				sizeof(mdev->model));
> +		if (usbdev->serial)
> +			strlcpy(mdev->serial, usbdev->serial,
> +				sizeof(mdev->serial));
> +		strcpy(mdev->bus_info, usbdev->devpath);
> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
> +		media_device_init(mdev);
> +	}
> +	if (!media_devnode_is_registered(&mdev->devnode)) {
> +		ret = media_device_register(mdev);

The device registration in ALSA happens not immediately at the call of
create but triggered via device dev_register callback.  I don't think
this would be a big problem but still this may leave some race,
e.g. MC device appears without the actual sound device during probe.


> +		if (ret) {
> +			dev_err(&usbdev->dev,
> +				"Couldn't register media device. Error: %d\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +	return 0;
> +}
> +
> +void media_device_delete(struct usb_interface *iface)
> +{
> +	struct media_device *mdev;
> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> +
> +	mdev = media_device_find_devres(&usbdev->dev);
> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
> +		media_device_unregister(mdev);
> +}
> +
> +static int media_enable_source(struct media_ctl *mctl)
> +{
> +	if (mctl && mctl->media_dev->enable_source)
> +		return mctl->media_dev->enable_source(&mctl->media_entity,
> +						      &mctl->media_pipe);
> +	return 0;
> +}
> +
> +static void media_disable_source(struct media_ctl *mctl)
> +{
> +	if (mctl && mctl->media_dev->disable_source)
> +		mctl->media_dev->disable_source(&mctl->media_entity);
> +}
> +
> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> +			int stream)
> +{
> +	struct media_device *mdev;
> +	struct media_ctl *mctl;
> +	struct device *pcm_dev = &pcm->streams[stream].dev;
> +	u32 intf_type;
> +	int ret = 0;
> +
> +	mdev = media_device_find_devres(&subs->dev->dev);
> +	if (!mdev)
> +		return -ENODEV;
> +
> +	if (subs->media_ctl)
> +		return 0;
> +
> +	/* allocate media_ctl */
> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
> +	if (!mctl)
> +		return -ENOMEM;
> +
> +	mctl->media_dev = mdev;
> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
> +	} else {
> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
> +	}
> +	mctl->media_entity.name = pcm->name;
> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;

Is it always a sink, no source, no matter which direction, playback or
capture?


thanks,

Takashi

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Takashi Iwai]

On Thu, 21 Jan 2016 19:09:50 +0100,
Shuah Khan wrote:
> 
> Change ALSA driver to use Managed Media Managed Controller
> API to share tuner with DVB and V4L2 drivers that control
> AU0828 media device.  Media device is created based on a
> newly added field value in the struct snd_usb_audio_quirk.
> Using this approach, the media controller API usage can be
> added for a specific device. In this patch, Media Controller
> API is enabled for AU0828 hw. snd_usb_create_quirk() will
> check this new field, if set will create a media device using
> media_device_get_devres() interface.
> 
> media_device_get_devres() will allocate a new media device
> devres or return an existing one, if it finds one.
> 
> During probe, media usb driver could have created the media
> device devres. It will then initialze (if necessary) and
> register the media device if it isn't already initialized
> and registered. Media device unregister is done from
> usb_audio_disconnect().
> 
> During probe, media usb driver could have created the
> media device devres. It will then register the media
> device if it isn't already registered. Media device
> unregister is done from usb_audio_disconnect().
> 
> New structure media_ctl is added to group the new
> fields to support media entity and links. This new
> structure is added to struct snd_usb_substream.
> 
> A new entity_notify hook and a new ALSA capture media
> entity are registered from snd_usb_pcm_open() after
> setting up hardware information for the PCM device.
> 
> When a new entity is registered, Media Controller API
> interface media_device_register_entity() invokes all
> registered entity_notify hooks for the media device.
> ALSA entity_notify hook parses all the entity list to
> find a link from decoder it ALSA entity. This indicates
> that the bridge driver created a link from decoder to
> ALSA capture entity.
> 
> ALSA will attempt to enable the tuner to link the tuner
> to the decoder calling enable_source handler if one is
> provided by the bridge driver prior to starting Media
> pipeline from snd_usb_hw_params(). If enable_source returns
> with tuner busy condition, then snd_usb_hw_params() will fail
> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
> 
> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
> ---
>  sound/usb/Kconfig        |   4 ++
>  sound/usb/Makefile       |   2 +
>  sound/usb/card.c         |   7 ++
>  sound/usb/card.h         |   1 +
>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
>  sound/usb/media.h        |  55 ++++++++++++++
>  sound/usb/pcm.c          |  28 ++++++--
>  sound/usb/quirks-table.h |   1 +
>  sound/usb/quirks.c       |   5 ++
>  sound/usb/stream.c       |   2 +
>  sound/usb/usbaudio.h     |   1 +
>  11 files changed, 285 insertions(+), 5 deletions(-)
>  create mode 100644 sound/usb/media.c
>  create mode 100644 sound/usb/media.h
> 
> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
> index a452ad7..1a71d93 100644
> --- a/sound/usb/Kconfig
> +++ b/sound/usb/Kconfig
> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
>  	select SND_RAWMIDI
>  	select SND_PCM
>  	select BITREVERSE
> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
>  	help
>  	  Say Y here to include support for USB audio and USB MIDI
>  	  devices.
> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called snd-usb-audio.
>  
> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
> +	bool
> +
>  config SND_USB_UA101
>  	tristate "Edirol UA-101/UA-1000 driver"
>  	select SND_PCM
> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
> index 2d2d122..8dca3c4 100644
> --- a/sound/usb/Makefile
> +++ b/sound/usb/Makefile
> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
>  			quirks.o \
>  			stream.o
>  
> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
> +
>  snd-usbmidi-lib-objs := midi.o
>  
>  # Toplevel Module Dependency
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index 1f09d95..3b226ed 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -66,6 +66,7 @@
>  #include "format.h"
>  #include "power.h"
>  #include "stream.h"
> +#include "media.h"
>  
>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
>  MODULE_DESCRIPTION("USB Audio");
> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
>  			snd_usb_mixer_disconnect(mixer);
>  		}
> +		/*
> +		 * Nice to check quirk && quirk->media_device
> +		 * need some special handlings. Doesn't look like
> +		 * we have access to quirk here
> +		*/
> +		media_device_delete(intf);
>  	}
>  
>  	chip->num_interfaces--;
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index 71778ca..c15a03c 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -156,6 +156,7 @@ struct snd_usb_substream {
>  	} dsd_dop;
>  
>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
> +	void *media_ctl;
>  };
>  
>  struct snd_usb_stream {
> diff --git a/sound/usb/media.c b/sound/usb/media.c
> new file mode 100644
> index 0000000..0987f40
> --- /dev/null
> +++ b/sound/usb/media.c
> @@ -0,0 +1,184 @@
> +/*
> + * media.c - Media Controller specific ALSA driver code
> + *
> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> + *
> + * This file is released under the GPLv2.
> + */
> +
> +/*
> + * This file adds Media Controller support to ALSA driver
> + * to use the Media Controller API to share tuner with DVB
> + * and V4L2 drivers that control media device. Media device
> + * is created based on existing quirks framework. Using this
> + * approach, the media controller API usage can be added for
> + * a specific device.
> +*/
> +
> +#include <linux/init.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/usb.h>
> +
> +#include <sound/pcm.h>
> +
> +#include "usbaudio.h"
> +#include "card.h"
> +#include "media.h"
> +
> +int media_device_create(struct snd_usb_audio *chip,
> +			struct usb_interface *iface)
> +{
> +	struct media_device *mdev;
> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> +	int ret;
> +
> +	mdev = media_device_get_devres(&usbdev->dev);
> +	if (!mdev)
> +		return -ENOMEM;
> +	if (!mdev->dev) {
> +		/* register media device */
> +		mdev->dev = &usbdev->dev;
> +		if (usbdev->product)
> +			strlcpy(mdev->model, usbdev->product,
> +				sizeof(mdev->model));
> +		if (usbdev->serial)
> +			strlcpy(mdev->serial, usbdev->serial,
> +				sizeof(mdev->serial));
> +		strcpy(mdev->bus_info, usbdev->devpath);
> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
> +		media_device_init(mdev);
> +	}
> +	if (!media_devnode_is_registered(&mdev->devnode)) {
> +		ret = media_device_register(mdev);

The device registration in ALSA happens not immediately at the call of
create but triggered via device dev_register callback.  I don't think
this would be a big problem but still this may leave some race,
e.g. MC device appears without the actual sound device during probe.


> +		if (ret) {
> +			dev_err(&usbdev->dev,
> +				"Couldn't register media device. Error: %d\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +	return 0;
> +}
> +
> +void media_device_delete(struct usb_interface *iface)
> +{
> +	struct media_device *mdev;
> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> +
> +	mdev = media_device_find_devres(&usbdev->dev);
> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
> +		media_device_unregister(mdev);
> +}
> +
> +static int media_enable_source(struct media_ctl *mctl)
> +{
> +	if (mctl && mctl->media_dev->enable_source)
> +		return mctl->media_dev->enable_source(&mctl->media_entity,
> +						      &mctl->media_pipe);
> +	return 0;
> +}
> +
> +static void media_disable_source(struct media_ctl *mctl)
> +{
> +	if (mctl && mctl->media_dev->disable_source)
> +		mctl->media_dev->disable_source(&mctl->media_entity);
> +}
> +
> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> +			int stream)
> +{
> +	struct media_device *mdev;
> +	struct media_ctl *mctl;
> +	struct device *pcm_dev = &pcm->streams[stream].dev;
> +	u32 intf_type;
> +	int ret = 0;
> +
> +	mdev = media_device_find_devres(&subs->dev->dev);
> +	if (!mdev)
> +		return -ENODEV;
> +
> +	if (subs->media_ctl)
> +		return 0;
> +
> +	/* allocate media_ctl */
> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
> +	if (!mctl)
> +		return -ENOMEM;
> +
> +	mctl->media_dev = mdev;
> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
> +	} else {
> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
> +	}
> +	mctl->media_entity.name = pcm->name;
> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;

Is it always a sink, no source, no matter which direction, playback or
capture?


thanks,

Takashi

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Shuah Khan]

On 02/01/2016 09:33 AM, Takashi Iwai wrote:
> On Thu, 21 Jan 2016 19:09:50 +0100,
> Shuah Khan wrote:
>>
>> Change ALSA driver to use Managed Media Managed Controller
>> API to share tuner with DVB and V4L2 drivers that control
>> AU0828 media device.  Media device is created based on a
>> newly added field value in the struct snd_usb_audio_quirk.
>> Using this approach, the media controller API usage can be
>> added for a specific device. In this patch, Media Controller
>> API is enabled for AU0828 hw. snd_usb_create_quirk() will
>> check this new field, if set will create a media device using
>> media_device_get_devres() interface.
>>
>> media_device_get_devres() will allocate a new media device
>> devres or return an existing one, if it finds one.
>>
>> During probe, media usb driver could have created the media
>> device devres. It will then initialze (if necessary) and
>> register the media device if it isn't already initialized
>> and registered. Media device unregister is done from
>> usb_audio_disconnect().
>>
>> During probe, media usb driver could have created the
>> media device devres. It will then register the media
>> device if it isn't already registered. Media device
>> unregister is done from usb_audio_disconnect().
>>
>> New structure media_ctl is added to group the new
>> fields to support media entity and links. This new
>> structure is added to struct snd_usb_substream.
>>
>> A new entity_notify hook and a new ALSA capture media
>> entity are registered from snd_usb_pcm_open() after
>> setting up hardware information for the PCM device.
>>
>> When a new entity is registered, Media Controller API
>> interface media_device_register_entity() invokes all
>> registered entity_notify hooks for the media device.
>> ALSA entity_notify hook parses all the entity list to
>> find a link from decoder it ALSA entity. This indicates
>> that the bridge driver created a link from decoder to
>> ALSA capture entity.
>>
>> ALSA will attempt to enable the tuner to link the tuner
>> to the decoder calling enable_source handler if one is
>> provided by the bridge driver prior to starting Media
>> pipeline from snd_usb_hw_params(). If enable_source returns
>> with tuner busy condition, then snd_usb_hw_params() will fail
>> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
>>
>> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
>> ---
>>  sound/usb/Kconfig        |   4 ++
>>  sound/usb/Makefile       |   2 +
>>  sound/usb/card.c         |   7 ++
>>  sound/usb/card.h         |   1 +
>>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
>>  sound/usb/media.h        |  55 ++++++++++++++
>>  sound/usb/pcm.c          |  28 ++++++--
>>  sound/usb/quirks-table.h |   1 +
>>  sound/usb/quirks.c       |   5 ++
>>  sound/usb/stream.c       |   2 +
>>  sound/usb/usbaudio.h     |   1 +
>>  11 files changed, 285 insertions(+), 5 deletions(-)
>>  create mode 100644 sound/usb/media.c
>>  create mode 100644 sound/usb/media.h
>>
>> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
>> index a452ad7..1a71d93 100644
>> --- a/sound/usb/Kconfig
>> +++ b/sound/usb/Kconfig
>> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
>>  	select SND_RAWMIDI
>>  	select SND_PCM
>>  	select BITREVERSE
>> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
>>  	help
>>  	  Say Y here to include support for USB audio and USB MIDI
>>  	  devices.
>> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
>>  	  To compile this driver as a module, choose M here: the module
>>  	  will be called snd-usb-audio.
>>  
>> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
>> +	bool
>> +
>>  config SND_USB_UA101
>>  	tristate "Edirol UA-101/UA-1000 driver"
>>  	select SND_PCM
>> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
>> index 2d2d122..8dca3c4 100644
>> --- a/sound/usb/Makefile
>> +++ b/sound/usb/Makefile
>> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
>>  			quirks.o \
>>  			stream.o
>>  
>> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
>> +
>>  snd-usbmidi-lib-objs := midi.o
>>  
>>  # Toplevel Module Dependency
>> diff --git a/sound/usb/card.c b/sound/usb/card.c
>> index 1f09d95..3b226ed 100644
>> --- a/sound/usb/card.c
>> +++ b/sound/usb/card.c
>> @@ -66,6 +66,7 @@
>>  #include "format.h"
>>  #include "power.h"
>>  #include "stream.h"
>> +#include "media.h"
>>  
>>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
>>  MODULE_DESCRIPTION("USB Audio");
>> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
>>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
>>  			snd_usb_mixer_disconnect(mixer);
>>  		}
>> +		/*
>> +		 * Nice to check quirk && quirk->media_device
>> +		 * need some special handlings. Doesn't look like
>> +		 * we have access to quirk here
>> +		*/
>> +		media_device_delete(intf);
>>  	}
>>  
>>  	chip->num_interfaces--;
>> diff --git a/sound/usb/card.h b/sound/usb/card.h
>> index 71778ca..c15a03c 100644
>> --- a/sound/usb/card.h
>> +++ b/sound/usb/card.h
>> @@ -156,6 +156,7 @@ struct snd_usb_substream {
>>  	} dsd_dop;
>>  
>>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
>> +	void *media_ctl;
>>  };
>>  
>>  struct snd_usb_stream {
>> diff --git a/sound/usb/media.c b/sound/usb/media.c
>> new file mode 100644
>> index 0000000..0987f40
>> --- /dev/null
>> +++ b/sound/usb/media.c
>> @@ -0,0 +1,184 @@
>> +/*
>> + * media.c - Media Controller specific ALSA driver code
>> + *
>> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
>> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
>> + *
>> + * This file is released under the GPLv2.
>> + */
>> +
>> +/*
>> + * This file adds Media Controller support to ALSA driver
>> + * to use the Media Controller API to share tuner with DVB
>> + * and V4L2 drivers that control media device. Media device
>> + * is created based on existing quirks framework. Using this
>> + * approach, the media controller API usage can be added for
>> + * a specific device.
>> +*/
>> +
>> +#include <linux/init.h>
>> +#include <linux/list.h>
>> +#include <linux/mutex.h>
>> +#include <linux/slab.h>
>> +#include <linux/usb.h>
>> +
>> +#include <sound/pcm.h>
>> +
>> +#include "usbaudio.h"
>> +#include "card.h"
>> +#include "media.h"
>> +
>> +int media_device_create(struct snd_usb_audio *chip,
>> +			struct usb_interface *iface)
>> +{
>> +	struct media_device *mdev;
>> +	struct usb_device *usbdev = interface_to_usbdev(iface);
>> +	int ret;
>> +
>> +	mdev = media_device_get_devres(&usbdev->dev);
>> +	if (!mdev)
>> +		return -ENOMEM;
>> +	if (!mdev->dev) {
>> +		/* register media device */
>> +		mdev->dev = &usbdev->dev;
>> +		if (usbdev->product)
>> +			strlcpy(mdev->model, usbdev->product,
>> +				sizeof(mdev->model));
>> +		if (usbdev->serial)
>> +			strlcpy(mdev->serial, usbdev->serial,
>> +				sizeof(mdev->serial));
>> +		strcpy(mdev->bus_info, usbdev->devpath);
>> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
>> +		media_device_init(mdev);
>> +	}
>> +	if (!media_devnode_is_registered(&mdev->devnode)) {
>> +		ret = media_device_register(mdev);
> 
> The device registration in ALSA happens not immediately at the call of
> create but triggered via device dev_register callback.  I don't think
> this would be a big problem but still this may leave some race,
> e.g. MC device appears without the actual sound device during probe.

Creation and register both happen in media_device_create()
when it gets called during quirk handling for au0828 device.
You are right that ALSA attempts to init and register media
device before sound device during probe. As such, au0828
gets to this step of initializing and registering media
device before snd-usb-audio probe runs.

To avoid races with au0828, the following logic is in
place.

The reason for the checks if (!mdev->dev) is that au0828
could have done the media_device_init(mdev) by the time
ALSA attempts media_device_create() and it could have
registered the device as well. Hence, the reason for the
second check if (!media_devnode_is_registered(&mdev->devnode))

Are you concerned about other races within snd-usb-audio?
I can change it to do the media_device_create() step towards
the end of sound probe after the snd_card_register(0 step.
Please let me know your preference.

> 
> 
>> +		if (ret) {
>> +			dev_err(&usbdev->dev,
>> +				"Couldn't register media device. Error: %d\n",
>> +				ret);
>> +			return ret;
>> +		}
>> +	}
>> +	return 0;
>> +}
>> +
>> +void media_device_delete(struct usb_interface *iface)
>> +{
>> +	struct media_device *mdev;
>> +	struct usb_device *usbdev = interface_to_usbdev(iface);
>> +
>> +	mdev = media_device_find_devres(&usbdev->dev);
>> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
>> +		media_device_unregister(mdev);
>> +}
>> +
>> +static int media_enable_source(struct media_ctl *mctl)
>> +{
>> +	if (mctl && mctl->media_dev->enable_source)
>> +		return mctl->media_dev->enable_source(&mctl->media_entity,
>> +						      &mctl->media_pipe);
>> +	return 0;
>> +}
>> +
>> +static void media_disable_source(struct media_ctl *mctl)
>> +{
>> +	if (mctl && mctl->media_dev->disable_source)
>> +		mctl->media_dev->disable_source(&mctl->media_entity);
>> +}
>> +
>> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
>> +			int stream)
>> +{
>> +	struct media_device *mdev;
>> +	struct media_ctl *mctl;
>> +	struct device *pcm_dev = &pcm->streams[stream].dev;
>> +	u32 intf_type;
>> +	int ret = 0;
>> +
>> +	mdev = media_device_find_devres(&subs->dev->dev);
>> +	if (!mdev)
>> +		return -ENODEV;
>> +
>> +	if (subs->media_ctl)
>> +		return 0;
>> +
>> +	/* allocate media_ctl */
>> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
>> +	if (!mctl)
>> +		return -ENOMEM;
>> +
>> +	mctl->media_dev = mdev;
>> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
>> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
>> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
>> +	} else {
>> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
>> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
>> +	}
>> +	mctl->media_entity.name = pcm->name;
>> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
>> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
>> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
> 
> Is it always a sink, no source, no matter which direction, playback or
> capture?
> 

Yes it is always a SINK in both cases. The source is
the audio decoder for both PCM capture and Playback
nodes.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Shuah Khan]

On 02/01/2016 09:33 AM, Takashi Iwai wrote:
> On Thu, 21 Jan 2016 19:09:50 +0100,
> Shuah Khan wrote:
>>
>> Change ALSA driver to use Managed Media Managed Controller
>> API to share tuner with DVB and V4L2 drivers that control
>> AU0828 media device.  Media device is created based on a
>> newly added field value in the struct snd_usb_audio_quirk.
>> Using this approach, the media controller API usage can be
>> added for a specific device. In this patch, Media Controller
>> API is enabled for AU0828 hw. snd_usb_create_quirk() will
>> check this new field, if set will create a media device using
>> media_device_get_devres() interface.
>>
>> media_device_get_devres() will allocate a new media device
>> devres or return an existing one, if it finds one.
>>
>> During probe, media usb driver could have created the media
>> device devres. It will then initialze (if necessary) and
>> register the media device if it isn't already initialized
>> and registered. Media device unregister is done from
>> usb_audio_disconnect().
>>
>> During probe, media usb driver could have created the
>> media device devres. It will then register the media
>> device if it isn't already registered. Media device
>> unregister is done from usb_audio_disconnect().
>>
>> New structure media_ctl is added to group the new
>> fields to support media entity and links. This new
>> structure is added to struct snd_usb_substream.
>>
>> A new entity_notify hook and a new ALSA capture media
>> entity are registered from snd_usb_pcm_open() after
>> setting up hardware information for the PCM device.
>>
>> When a new entity is registered, Media Controller API
>> interface media_device_register_entity() invokes all
>> registered entity_notify hooks for the media device.
>> ALSA entity_notify hook parses all the entity list to
>> find a link from decoder it ALSA entity. This indicates
>> that the bridge driver created a link from decoder to
>> ALSA capture entity.
>>
>> ALSA will attempt to enable the tuner to link the tuner
>> to the decoder calling enable_source handler if one is
>> provided by the bridge driver prior to starting Media
>> pipeline from snd_usb_hw_params(). If enable_source returns
>> with tuner busy condition, then snd_usb_hw_params() will fail
>> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
>>
>> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
>> ---
>>  sound/usb/Kconfig        |   4 ++
>>  sound/usb/Makefile       |   2 +
>>  sound/usb/card.c         |   7 ++
>>  sound/usb/card.h         |   1 +
>>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
>>  sound/usb/media.h        |  55 ++++++++++++++
>>  sound/usb/pcm.c          |  28 ++++++--
>>  sound/usb/quirks-table.h |   1 +
>>  sound/usb/quirks.c       |   5 ++
>>  sound/usb/stream.c       |   2 +
>>  sound/usb/usbaudio.h     |   1 +
>>  11 files changed, 285 insertions(+), 5 deletions(-)
>>  create mode 100644 sound/usb/media.c
>>  create mode 100644 sound/usb/media.h
>>
>> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
>> index a452ad7..1a71d93 100644
>> --- a/sound/usb/Kconfig
>> +++ b/sound/usb/Kconfig
>> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
>>  	select SND_RAWMIDI
>>  	select SND_PCM
>>  	select BITREVERSE
>> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
>>  	help
>>  	  Say Y here to include support for USB audio and USB MIDI
>>  	  devices.
>> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
>>  	  To compile this driver as a module, choose M here: the module
>>  	  will be called snd-usb-audio.
>>  
>> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
>> +	bool
>> +
>>  config SND_USB_UA101
>>  	tristate "Edirol UA-101/UA-1000 driver"
>>  	select SND_PCM
>> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
>> index 2d2d122..8dca3c4 100644
>> --- a/sound/usb/Makefile
>> +++ b/sound/usb/Makefile
>> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
>>  			quirks.o \
>>  			stream.o
>>  
>> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
>> +
>>  snd-usbmidi-lib-objs := midi.o
>>  
>>  # Toplevel Module Dependency
>> diff --git a/sound/usb/card.c b/sound/usb/card.c
>> index 1f09d95..3b226ed 100644
>> --- a/sound/usb/card.c
>> +++ b/sound/usb/card.c
>> @@ -66,6 +66,7 @@
>>  #include "format.h"
>>  #include "power.h"
>>  #include "stream.h"
>> +#include "media.h"
>>  
>>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
>>  MODULE_DESCRIPTION("USB Audio");
>> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
>>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
>>  			snd_usb_mixer_disconnect(mixer);
>>  		}
>> +		/*
>> +		 * Nice to check quirk && quirk->media_device
>> +		 * need some special handlings. Doesn't look like
>> +		 * we have access to quirk here
>> +		*/
>> +		media_device_delete(intf);
>>  	}
>>  
>>  	chip->num_interfaces--;
>> diff --git a/sound/usb/card.h b/sound/usb/card.h
>> index 71778ca..c15a03c 100644
>> --- a/sound/usb/card.h
>> +++ b/sound/usb/card.h
>> @@ -156,6 +156,7 @@ struct snd_usb_substream {
>>  	} dsd_dop;
>>  
>>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
>> +	void *media_ctl;
>>  };
>>  
>>  struct snd_usb_stream {
>> diff --git a/sound/usb/media.c b/sound/usb/media.c
>> new file mode 100644
>> index 0000000..0987f40
>> --- /dev/null
>> +++ b/sound/usb/media.c
>> @@ -0,0 +1,184 @@
>> +/*
>> + * media.c - Media Controller specific ALSA driver code
>> + *
>> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
>> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
>> + *
>> + * This file is released under the GPLv2.
>> + */
>> +
>> +/*
>> + * This file adds Media Controller support to ALSA driver
>> + * to use the Media Controller API to share tuner with DVB
>> + * and V4L2 drivers that control media device. Media device
>> + * is created based on existing quirks framework. Using this
>> + * approach, the media controller API usage can be added for
>> + * a specific device.
>> +*/
>> +
>> +#include <linux/init.h>
>> +#include <linux/list.h>
>> +#include <linux/mutex.h>
>> +#include <linux/slab.h>
>> +#include <linux/usb.h>
>> +
>> +#include <sound/pcm.h>
>> +
>> +#include "usbaudio.h"
>> +#include "card.h"
>> +#include "media.h"
>> +
>> +int media_device_create(struct snd_usb_audio *chip,
>> +			struct usb_interface *iface)
>> +{
>> +	struct media_device *mdev;
>> +	struct usb_device *usbdev = interface_to_usbdev(iface);
>> +	int ret;
>> +
>> +	mdev = media_device_get_devres(&usbdev->dev);
>> +	if (!mdev)
>> +		return -ENOMEM;
>> +	if (!mdev->dev) {
>> +		/* register media device */
>> +		mdev->dev = &usbdev->dev;
>> +		if (usbdev->product)
>> +			strlcpy(mdev->model, usbdev->product,
>> +				sizeof(mdev->model));
>> +		if (usbdev->serial)
>> +			strlcpy(mdev->serial, usbdev->serial,
>> +				sizeof(mdev->serial));
>> +		strcpy(mdev->bus_info, usbdev->devpath);
>> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
>> +		media_device_init(mdev);
>> +	}
>> +	if (!media_devnode_is_registered(&mdev->devnode)) {
>> +		ret = media_device_register(mdev);
> 
> The device registration in ALSA happens not immediately at the call of
> create but triggered via device dev_register callback.  I don't think
> this would be a big problem but still this may leave some race,
> e.g. MC device appears without the actual sound device during probe.

Creation and register both happen in media_device_create()
when it gets called during quirk handling for au0828 device.
You are right that ALSA attempts to init and register media
device before sound device during probe. As such, au0828
gets to this step of initializing and registering media
device before snd-usb-audio probe runs.

To avoid races with au0828, the following logic is in
place.

The reason for the checks if (!mdev->dev) is that au0828
could have done the media_device_init(mdev) by the time
ALSA attempts media_device_create() and it could have
registered the device as well. Hence, the reason for the
second check if (!media_devnode_is_registered(&mdev->devnode))

Are you concerned about other races within snd-usb-audio?
I can change it to do the media_device_create() step towards
the end of sound probe after the snd_card_register(0 step.
Please let me know your preference.

> 
> 
>> +		if (ret) {
>> +			dev_err(&usbdev->dev,
>> +				"Couldn't register media device. Error: %d\n",
>> +				ret);
>> +			return ret;
>> +		}
>> +	}
>> +	return 0;
>> +}
>> +
>> +void media_device_delete(struct usb_interface *iface)
>> +{
>> +	struct media_device *mdev;
>> +	struct usb_device *usbdev = interface_to_usbdev(iface);
>> +
>> +	mdev = media_device_find_devres(&usbdev->dev);
>> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
>> +		media_device_unregister(mdev);
>> +}
>> +
>> +static int media_enable_source(struct media_ctl *mctl)
>> +{
>> +	if (mctl && mctl->media_dev->enable_source)
>> +		return mctl->media_dev->enable_source(&mctl->media_entity,
>> +						      &mctl->media_pipe);
>> +	return 0;
>> +}
>> +
>> +static void media_disable_source(struct media_ctl *mctl)
>> +{
>> +	if (mctl && mctl->media_dev->disable_source)
>> +		mctl->media_dev->disable_source(&mctl->media_entity);
>> +}
>> +
>> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
>> +			int stream)
>> +{
>> +	struct media_device *mdev;
>> +	struct media_ctl *mctl;
>> +	struct device *pcm_dev = &pcm->streams[stream].dev;
>> +	u32 intf_type;
>> +	int ret = 0;
>> +
>> +	mdev = media_device_find_devres(&subs->dev->dev);
>> +	if (!mdev)
>> +		return -ENODEV;
>> +
>> +	if (subs->media_ctl)
>> +		return 0;
>> +
>> +	/* allocate media_ctl */
>> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
>> +	if (!mctl)
>> +		return -ENOMEM;
>> +
>> +	mctl->media_dev = mdev;
>> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
>> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
>> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
>> +	} else {
>> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
>> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
>> +	}
>> +	mctl->media_entity.name = pcm->name;
>> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
>> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);
>> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
> 
> Is it always a sink, no source, no matter which direction, playback or
> capture?
> 

Yes it is always a SINK in both cases. The source is
the audio decoder for both PCM capture and Playback
nodes.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Mauro Carvalho Chehab]

Em Mon, 01 Feb 2016 11:00:47 -0700
Shuah Khan <shuahkh@osg.samsung.com> escreveu:

> On 02/01/2016 09:33 AM, Takashi Iwai wrote:
> > On Thu, 21 Jan 2016 19:09:50 +0100,
> > Shuah Khan wrote:  
> >>
> >> Change ALSA driver to use Managed Media Managed Controller
> >> API to share tuner with DVB and V4L2 drivers that control
> >> AU0828 media device.  Media device is created based on a
> >> newly added field value in the struct snd_usb_audio_quirk.
> >> Using this approach, the media controller API usage can be
> >> added for a specific device. In this patch, Media Controller
> >> API is enabled for AU0828 hw. snd_usb_create_quirk() will
> >> check this new field, if set will create a media device using
> >> media_device_get_devres() interface.
> >>
> >> media_device_get_devres() will allocate a new media device
> >> devres or return an existing one, if it finds one.
> >>
> >> During probe, media usb driver could have created the media
> >> device devres. It will then initialze (if necessary) and
> >> register the media device if it isn't already initialized
> >> and registered. Media device unregister is done from
> >> usb_audio_disconnect().
> >>
> >> During probe, media usb driver could have created the
> >> media device devres. It will then register the media
> >> device if it isn't already registered. Media device
> >> unregister is done from usb_audio_disconnect().
> >>
> >> New structure media_ctl is added to group the new
> >> fields to support media entity and links. This new
> >> structure is added to struct snd_usb_substream.
> >>
> >> A new entity_notify hook and a new ALSA capture media
> >> entity are registered from snd_usb_pcm_open() after
> >> setting up hardware information for the PCM device.
> >>
> >> When a new entity is registered, Media Controller API
> >> interface media_device_register_entity() invokes all
> >> registered entity_notify hooks for the media device.
> >> ALSA entity_notify hook parses all the entity list to
> >> find a link from decoder it ALSA entity. This indicates
> >> that the bridge driver created a link from decoder to
> >> ALSA capture entity.
> >>
> >> ALSA will attempt to enable the tuner to link the tuner
> >> to the decoder calling enable_source handler if one is
> >> provided by the bridge driver prior to starting Media
> >> pipeline from snd_usb_hw_params(). If enable_source returns
> >> with tuner busy condition, then snd_usb_hw_params() will fail
> >> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
> >>
> >> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
> >> ---
> >>  sound/usb/Kconfig        |   4 ++
> >>  sound/usb/Makefile       |   2 +
> >>  sound/usb/card.c         |   7 ++
> >>  sound/usb/card.h         |   1 +
> >>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
> >>  sound/usb/media.h        |  55 ++++++++++++++
> >>  sound/usb/pcm.c          |  28 ++++++--
> >>  sound/usb/quirks-table.h |   1 +
> >>  sound/usb/quirks.c       |   5 ++
> >>  sound/usb/stream.c       |   2 +
> >>  sound/usb/usbaudio.h     |   1 +
> >>  11 files changed, 285 insertions(+), 5 deletions(-)
> >>  create mode 100644 sound/usb/media.c
> >>  create mode 100644 sound/usb/media.h
> >>
> >> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
> >> index a452ad7..1a71d93 100644
> >> --- a/sound/usb/Kconfig
> >> +++ b/sound/usb/Kconfig
> >> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
> >>  	select SND_RAWMIDI
> >>  	select SND_PCM
> >>  	select BITREVERSE
> >> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
> >>  	help
> >>  	  Say Y here to include support for USB audio and USB MIDI
> >>  	  devices.
> >> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
> >>  	  To compile this driver as a module, choose M here: the module
> >>  	  will be called snd-usb-audio.
> >>  
> >> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
> >> +	bool
> >> +
> >>  config SND_USB_UA101
> >>  	tristate "Edirol UA-101/UA-1000 driver"
> >>  	select SND_PCM
> >> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
> >> index 2d2d122..8dca3c4 100644
> >> --- a/sound/usb/Makefile
> >> +++ b/sound/usb/Makefile
> >> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
> >>  			quirks.o \
> >>  			stream.o
> >>  
> >> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
> >> +
> >>  snd-usbmidi-lib-objs := midi.o
> >>  
> >>  # Toplevel Module Dependency
> >> diff --git a/sound/usb/card.c b/sound/usb/card.c
> >> index 1f09d95..3b226ed 100644
> >> --- a/sound/usb/card.c
> >> +++ b/sound/usb/card.c
> >> @@ -66,6 +66,7 @@
> >>  #include "format.h"
> >>  #include "power.h"
> >>  #include "stream.h"
> >> +#include "media.h"
> >>  
> >>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
> >>  MODULE_DESCRIPTION("USB Audio");
> >> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
> >>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
> >>  			snd_usb_mixer_disconnect(mixer);
> >>  		}
> >> +		/*
> >> +		 * Nice to check quirk && quirk->media_device
> >> +		 * need some special handlings. Doesn't look like
> >> +		 * we have access to quirk here
> >> +		*/
> >> +		media_device_delete(intf);
> >>  	}
> >>  
> >>  	chip->num_interfaces--;
> >> diff --git a/sound/usb/card.h b/sound/usb/card.h
> >> index 71778ca..c15a03c 100644
> >> --- a/sound/usb/card.h
> >> +++ b/sound/usb/card.h
> >> @@ -156,6 +156,7 @@ struct snd_usb_substream {
> >>  	} dsd_dop;
> >>  
> >>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
> >> +	void *media_ctl;
> >>  };
> >>  
> >>  struct snd_usb_stream {
> >> diff --git a/sound/usb/media.c b/sound/usb/media.c
> >> new file mode 100644
> >> index 0000000..0987f40
> >> --- /dev/null
> >> +++ b/sound/usb/media.c
> >> @@ -0,0 +1,184 @@
> >> +/*
> >> + * media.c - Media Controller specific ALSA driver code
> >> + *
> >> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
> >> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> >> + *
> >> + * This file is released under the GPLv2.
> >> + */
> >> +
> >> +/*
> >> + * This file adds Media Controller support to ALSA driver
> >> + * to use the Media Controller API to share tuner with DVB
> >> + * and V4L2 drivers that control media device. Media device
> >> + * is created based on existing quirks framework. Using this
> >> + * approach, the media controller API usage can be added for
> >> + * a specific device.
> >> +*/
> >> +
> >> +#include <linux/init.h>
> >> +#include <linux/list.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/usb.h>
> >> +
> >> +#include <sound/pcm.h>
> >> +
> >> +#include "usbaudio.h"
> >> +#include "card.h"
> >> +#include "media.h"
> >> +
> >> +int media_device_create(struct snd_usb_audio *chip,
> >> +			struct usb_interface *iface)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> >> +	int ret;
> >> +
> >> +	mdev = media_device_get_devres(&usbdev->dev);
> >> +	if (!mdev)
> >> +		return -ENOMEM;
> >> +	if (!mdev->dev) {
> >> +		/* register media device */
> >> +		mdev->dev = &usbdev->dev;
> >> +		if (usbdev->product)
> >> +			strlcpy(mdev->model, usbdev->product,
> >> +				sizeof(mdev->model));
> >> +		if (usbdev->serial)
> >> +			strlcpy(mdev->serial, usbdev->serial,
> >> +				sizeof(mdev->serial));
> >> +		strcpy(mdev->bus_info, usbdev->devpath);
> >> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
> >> +		media_device_init(mdev);
> >> +	}
> >> +	if (!media_devnode_is_registered(&mdev->devnode)) {
> >> +		ret = media_device_register(mdev);  
> > 
> > The device registration in ALSA happens not immediately at the call of
> > create but triggered via device dev_register callback.  I don't think
> > this would be a big problem but still this may leave some race,
> > e.g. MC device appears without the actual sound device during probe.  

The best would be to register the media devnode at the callback
(if not registered already by the v4l2 driver), after the creation of
the sound devnodes.

> 
> Creation and register both happen in media_device_create()
> when it gets called during quirk handling for au0828 device.
> You are right that ALSA attempts to init and register media
> device before sound device during probe. As such, au0828
> gets to this step of initializing and registering media
> device before snd-usb-audio probe runs.
> 
> To avoid races with au0828, the following logic is in
> place.
> 
> The reason for the checks if (!mdev->dev) is that au0828
> could have done the media_device_init(mdev) by the time
> ALSA attempts media_device_create() and it could have
> registered the device as well. Hence, the reason for the
> second check if (!media_devnode_is_registered(&mdev->devnode))
> 
> Are you concerned about other races within snd-usb-audio?
> I can change it to do the media_device_create() step towards
> the end of sound probe after the snd_card_register(0 step.
> Please let me know your preference.
> 
> > 
> >   
> >> +		if (ret) {
> >> +			dev_err(&usbdev->dev,
> >> +				"Couldn't register media device. Error: %d\n",
> >> +				ret);
> >> +			return ret;
> >> +		}
> >> +	}
> >> +	return 0;
> >> +}
> >> +
> >> +void media_device_delete(struct usb_interface *iface)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> >> +
> >> +	mdev = media_device_find_devres(&usbdev->dev);
> >> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
> >> +		media_device_unregister(mdev);
> >> +}
> >> +
> >> +static int media_enable_source(struct media_ctl *mctl)
> >> +{
> >> +	if (mctl && mctl->media_dev->enable_source)
> >> +		return mctl->media_dev->enable_source(&mctl->media_entity,
> >> +						      &mctl->media_pipe);
> >> +	return 0;
> >> +}
> >> +
> >> +static void media_disable_source(struct media_ctl *mctl)
> >> +{
> >> +	if (mctl && mctl->media_dev->disable_source)
> >> +		mctl->media_dev->disable_source(&mctl->media_entity);
> >> +}
> >> +
> >> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> >> +			int stream)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct media_ctl *mctl;
> >> +	struct device *pcm_dev = &pcm->streams[stream].dev;
> >> +	u32 intf_type;
> >> +	int ret = 0;
> >> +
> >> +	mdev = media_device_find_devres(&subs->dev->dev);
> >> +	if (!mdev)
> >> +		return -ENODEV;
> >> +
> >> +	if (subs->media_ctl)
> >> +		return 0;
> >> +
> >> +	/* allocate media_ctl */
> >> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
> >> +	if (!mctl)
> >> +		return -ENOMEM;
> >> +
> >> +	mctl->media_dev = mdev;
> >> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
> >> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
> >> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
> >> +	} else {
> >> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
> >> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
> >> +	}
> >> +	mctl->media_entity.name = pcm->name;


> >> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
> >> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);

Please, don't initialize major/minor at the entity level. This should
be done only at interface level (and where backward compatible is
needed). Those fields are obsolete!

> >> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;  
> > 
> > Is it always a sink, no source, no matter which direction, playback or
> > capture?
> >   
> 
> Yes it is always a SINK in both cases. The source is
> the audio decoder for both PCM capture and Playback
> nodes.

That doesn't sound right: the direction is relevant.

What happens is that, from Kernelspace side, when a hardware is 
producing data, it is a SOURCE, and when it is consuming data, it is a
SINK.

The entities associated with an interface is weird, as a
SINK entity is actually sending data to userspace (so, the data
disappears from the Kernel), and a SOURCE entity is receiving data
from userspace.

So, for SNDRV_PCM_STREAM_CAPTURE, we have a SINK, and, for
SNDRV_PCM_STREAM_PLAYBACK, we have a SOURCE.

Regards,
Mauro

Re: [PATCH REBASE 4.5 26/31] sound/usb: Update ALSA driver to use Managed Media Controller API

[Mauro Carvalho Chehab]

Em Mon, 01 Feb 2016 11:00:47 -0700
Shuah Khan <shuahkh@osg.samsung.com> escreveu:

> On 02/01/2016 09:33 AM, Takashi Iwai wrote:
> > On Thu, 21 Jan 2016 19:09:50 +0100,
> > Shuah Khan wrote:  
> >>
> >> Change ALSA driver to use Managed Media Managed Controller
> >> API to share tuner with DVB and V4L2 drivers that control
> >> AU0828 media device.  Media device is created based on a
> >> newly added field value in the struct snd_usb_audio_quirk.
> >> Using this approach, the media controller API usage can be
> >> added for a specific device. In this patch, Media Controller
> >> API is enabled for AU0828 hw. snd_usb_create_quirk() will
> >> check this new field, if set will create a media device using
> >> media_device_get_devres() interface.
> >>
> >> media_device_get_devres() will allocate a new media device
> >> devres or return an existing one, if it finds one.
> >>
> >> During probe, media usb driver could have created the media
> >> device devres. It will then initialze (if necessary) and
> >> register the media device if it isn't already initialized
> >> and registered. Media device unregister is done from
> >> usb_audio_disconnect().
> >>
> >> During probe, media usb driver could have created the
> >> media device devres. It will then register the media
> >> device if it isn't already registered. Media device
> >> unregister is done from usb_audio_disconnect().
> >>
> >> New structure media_ctl is added to group the new
> >> fields to support media entity and links. This new
> >> structure is added to struct snd_usb_substream.
> >>
> >> A new entity_notify hook and a new ALSA capture media
> >> entity are registered from snd_usb_pcm_open() after
> >> setting up hardware information for the PCM device.
> >>
> >> When a new entity is registered, Media Controller API
> >> interface media_device_register_entity() invokes all
> >> registered entity_notify hooks for the media device.
> >> ALSA entity_notify hook parses all the entity list to
> >> find a link from decoder it ALSA entity. This indicates
> >> that the bridge driver created a link from decoder to
> >> ALSA capture entity.
> >>
> >> ALSA will attempt to enable the tuner to link the tuner
> >> to the decoder calling enable_source handler if one is
> >> provided by the bridge driver prior to starting Media
> >> pipeline from snd_usb_hw_params(). If enable_source returns
> >> with tuner busy condition, then snd_usb_hw_params() will fail
> >> with -EBUSY. Media pipeline is stopped from snd_usb_hw_free().
> >>
> >> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
> >> ---
> >>  sound/usb/Kconfig        |   4 ++
> >>  sound/usb/Makefile       |   2 +
> >>  sound/usb/card.c         |   7 ++
> >>  sound/usb/card.h         |   1 +
> >>  sound/usb/media.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
> >>  sound/usb/media.h        |  55 ++++++++++++++
> >>  sound/usb/pcm.c          |  28 ++++++--
> >>  sound/usb/quirks-table.h |   1 +
> >>  sound/usb/quirks.c       |   5 ++
> >>  sound/usb/stream.c       |   2 +
> >>  sound/usb/usbaudio.h     |   1 +
> >>  11 files changed, 285 insertions(+), 5 deletions(-)
> >>  create mode 100644 sound/usb/media.c
> >>  create mode 100644 sound/usb/media.h
> >>
> >> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
> >> index a452ad7..1a71d93 100644
> >> --- a/sound/usb/Kconfig
> >> +++ b/sound/usb/Kconfig
> >> @@ -15,6 +15,7 @@ config SND_USB_AUDIO
> >>  	select SND_RAWMIDI
> >>  	select SND_PCM
> >>  	select BITREVERSE
> >> +	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER	if MEDIA_CONTROLLER
> >>  	help
> >>  	  Say Y here to include support for USB audio and USB MIDI
> >>  	  devices.
> >> @@ -22,6 +23,9 @@ config SND_USB_AUDIO
> >>  	  To compile this driver as a module, choose M here: the module
> >>  	  will be called snd-usb-audio.
> >>  
> >> +config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
> >> +	bool
> >> +
> >>  config SND_USB_UA101
> >>  	tristate "Edirol UA-101/UA-1000 driver"
> >>  	select SND_PCM
> >> diff --git a/sound/usb/Makefile b/sound/usb/Makefile
> >> index 2d2d122..8dca3c4 100644
> >> --- a/sound/usb/Makefile
> >> +++ b/sound/usb/Makefile
> >> @@ -15,6 +15,8 @@ snd-usb-audio-objs := 	card.o \
> >>  			quirks.o \
> >>  			stream.o
> >>  
> >> +snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
> >> +
> >>  snd-usbmidi-lib-objs := midi.o
> >>  
> >>  # Toplevel Module Dependency
> >> diff --git a/sound/usb/card.c b/sound/usb/card.c
> >> index 1f09d95..3b226ed 100644
> >> --- a/sound/usb/card.c
> >> +++ b/sound/usb/card.c
> >> @@ -66,6 +66,7 @@
> >>  #include "format.h"
> >>  #include "power.h"
> >>  #include "stream.h"
> >> +#include "media.h"
> >>  
> >>  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
> >>  MODULE_DESCRIPTION("USB Audio");
> >> @@ -621,6 +622,12 @@ static void usb_audio_disconnect(struct usb_interface *intf)
> >>  		list_for_each_entry(mixer, &chip->mixer_list, list) {
> >>  			snd_usb_mixer_disconnect(mixer);
> >>  		}
> >> +		/*
> >> +		 * Nice to check quirk && quirk->media_device
> >> +		 * need some special handlings. Doesn't look like
> >> +		 * we have access to quirk here
> >> +		*/
> >> +		media_device_delete(intf);
> >>  	}
> >>  
> >>  	chip->num_interfaces--;
> >> diff --git a/sound/usb/card.h b/sound/usb/card.h
> >> index 71778ca..c15a03c 100644
> >> --- a/sound/usb/card.h
> >> +++ b/sound/usb/card.h
> >> @@ -156,6 +156,7 @@ struct snd_usb_substream {
> >>  	} dsd_dop;
> >>  
> >>  	bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
> >> +	void *media_ctl;
> >>  };
> >>  
> >>  struct snd_usb_stream {
> >> diff --git a/sound/usb/media.c b/sound/usb/media.c
> >> new file mode 100644
> >> index 0000000..0987f40
> >> --- /dev/null
> >> +++ b/sound/usb/media.c
> >> @@ -0,0 +1,184 @@
> >> +/*
> >> + * media.c - Media Controller specific ALSA driver code
> >> + *
> >> + * Copyright (c) 2015 Shuah Khan <shuahkh@osg.samsung.com>
> >> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> >> + *
> >> + * This file is released under the GPLv2.
> >> + */
> >> +
> >> +/*
> >> + * This file adds Media Controller support to ALSA driver
> >> + * to use the Media Controller API to share tuner with DVB
> >> + * and V4L2 drivers that control media device. Media device
> >> + * is created based on existing quirks framework. Using this
> >> + * approach, the media controller API usage can be added for
> >> + * a specific device.
> >> +*/
> >> +
> >> +#include <linux/init.h>
> >> +#include <linux/list.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/usb.h>
> >> +
> >> +#include <sound/pcm.h>
> >> +
> >> +#include "usbaudio.h"
> >> +#include "card.h"
> >> +#include "media.h"
> >> +
> >> +int media_device_create(struct snd_usb_audio *chip,
> >> +			struct usb_interface *iface)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> >> +	int ret;
> >> +
> >> +	mdev = media_device_get_devres(&usbdev->dev);
> >> +	if (!mdev)
> >> +		return -ENOMEM;
> >> +	if (!mdev->dev) {
> >> +		/* register media device */
> >> +		mdev->dev = &usbdev->dev;
> >> +		if (usbdev->product)
> >> +			strlcpy(mdev->model, usbdev->product,
> >> +				sizeof(mdev->model));
> >> +		if (usbdev->serial)
> >> +			strlcpy(mdev->serial, usbdev->serial,
> >> +				sizeof(mdev->serial));
> >> +		strcpy(mdev->bus_info, usbdev->devpath);
> >> +		mdev->hw_revision = le16_to_cpu(usbdev->descriptor.bcdDevice);
> >> +		media_device_init(mdev);
> >> +	}
> >> +	if (!media_devnode_is_registered(&mdev->devnode)) {
> >> +		ret = media_device_register(mdev);  
> > 
> > The device registration in ALSA happens not immediately at the call of
> > create but triggered via device dev_register callback.  I don't think
> > this would be a big problem but still this may leave some race,
> > e.g. MC device appears without the actual sound device during probe.  

The best would be to register the media devnode at the callback
(if not registered already by the v4l2 driver), after the creation of
the sound devnodes.

> 
> Creation and register both happen in media_device_create()
> when it gets called during quirk handling for au0828 device.
> You are right that ALSA attempts to init and register media
> device before sound device during probe. As such, au0828
> gets to this step of initializing and registering media
> device before snd-usb-audio probe runs.
> 
> To avoid races with au0828, the following logic is in
> place.
> 
> The reason for the checks if (!mdev->dev) is that au0828
> could have done the media_device_init(mdev) by the time
> ALSA attempts media_device_create() and it could have
> registered the device as well. Hence, the reason for the
> second check if (!media_devnode_is_registered(&mdev->devnode))
> 
> Are you concerned about other races within snd-usb-audio?
> I can change it to do the media_device_create() step towards
> the end of sound probe after the snd_card_register(0 step.
> Please let me know your preference.
> 
> > 
> >   
> >> +		if (ret) {
> >> +			dev_err(&usbdev->dev,
> >> +				"Couldn't register media device. Error: %d\n",
> >> +				ret);
> >> +			return ret;
> >> +		}
> >> +	}
> >> +	return 0;
> >> +}
> >> +
> >> +void media_device_delete(struct usb_interface *iface)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct usb_device *usbdev = interface_to_usbdev(iface);
> >> +
> >> +	mdev = media_device_find_devres(&usbdev->dev);
> >> +	if (mdev && media_devnode_is_registered(&mdev->devnode))
> >> +		media_device_unregister(mdev);
> >> +}
> >> +
> >> +static int media_enable_source(struct media_ctl *mctl)
> >> +{
> >> +	if (mctl && mctl->media_dev->enable_source)
> >> +		return mctl->media_dev->enable_source(&mctl->media_entity,
> >> +						      &mctl->media_pipe);
> >> +	return 0;
> >> +}
> >> +
> >> +static void media_disable_source(struct media_ctl *mctl)
> >> +{
> >> +	if (mctl && mctl->media_dev->disable_source)
> >> +		mctl->media_dev->disable_source(&mctl->media_entity);
> >> +}
> >> +
> >> +int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> >> +			int stream)
> >> +{
> >> +	struct media_device *mdev;
> >> +	struct media_ctl *mctl;
> >> +	struct device *pcm_dev = &pcm->streams[stream].dev;
> >> +	u32 intf_type;
> >> +	int ret = 0;
> >> +
> >> +	mdev = media_device_find_devres(&subs->dev->dev);
> >> +	if (!mdev)
> >> +		return -ENODEV;
> >> +
> >> +	if (subs->media_ctl)
> >> +		return 0;
> >> +
> >> +	/* allocate media_ctl */
> >> +	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
> >> +	if (!mctl)
> >> +		return -ENOMEM;
> >> +
> >> +	mctl->media_dev = mdev;
> >> +	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
> >> +		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
> >> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
> >> +	} else {
> >> +		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
> >> +		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
> >> +	}
> >> +	mctl->media_entity.name = pcm->name;


> >> +	mctl->media_entity.info.dev.major = MAJOR(pcm_dev->devt);
> >> +	mctl->media_entity.info.dev.minor = MINOR(pcm_dev->devt);

Please, don't initialize major/minor at the entity level. This should
be done only at interface level (and where backward compatible is
needed). Those fields are obsolete!

> >> +	mctl->media_pad.flags = MEDIA_PAD_FL_SINK;  
> > 
> > Is it always a sink, no source, no matter which direction, playback or
> > capture?
> >   
> 
> Yes it is always a SINK in both cases. The source is
> the audio decoder for both PCM capture and Playback
> nodes.

That doesn't sound right: the direction is relevant.

What happens is that, from Kernelspace side, when a hardware is 
producing data, it is a SOURCE, and when it is consuming data, it is a
SINK.

The entities associated with an interface is weird, as a
SINK entity is actually sending data to userspace (so, the data
disappears from the Kernel), and a SOURCE entity is receiving data
from userspace.

So, for SNDRV_PCM_STREAM_CAPTURE, we have a SINK, and, for
SNDRV_PCM_STREAM_PLAYBACK, we have a SOURCE.

Regards,
Mauro