On 02/26/2016 12:55 PM, Takashi Iwai wrote:
On Fri, 12 Feb 2016 00:41:38 +0100, Shuah Khan wrote:
Change ALSA driver to use Media Controller API to share media resources with DVB and V4L2 drivers on a AU0828 media device. Media Controller specific initialization is done after sound card is registered. ALSA creates Media interface and entity function graph nodes for Control, Mixer, PCM Playback, and PCM Capture devices.
snd_usb_hw_params() will call Media Controller enable source handler interface to request the media resource. If resource request is granted, it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is returned.
Media specific cleanup is done in usb_audio_disconnect().
Signed-off-by: Shuah Khan shuahkh@osg.samsung.com
sound/usb/Kconfig | 4 + sound/usb/Makefile | 2 + sound/usb/card.c | 14 +++ sound/usb/card.h | 3 + sound/usb/media.c | 318 +++++++++++++++++++++++++++++++++++++++++++++++ sound/usb/media.h | 72 +++++++++++ sound/usb/mixer.h | 3 + sound/usb/pcm.c | 28 ++++- sound/usb/quirks-table.h | 1 + sound/usb/stream.c | 2 + sound/usb/usbaudio.h | 6 + 11 files changed, 448 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..ba117f5 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 && MEDIA_SUPPORT
Looking at the media Kconfig again, this would be broken if MEDIA_SUPPORT=m and SND_USB_AUDIO=y. The ugly workaround is something like: select SND_USB_AUDIO_USE_MEDIA_CONTROLLER \ if MEDIA_CONTROLLER && (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND)
My current config is MEDIA_SUPPORT=m and SND_USB_AUDIO=y It is working and I didn't see any issues so far. Maybe the current change is good. I am hoping kbuild-bot can find issues (if any) once it gets merged.
Other than that, it looks more or less OK to me. The way how media_stream_init() gets called is a bit worrisome, but it should work practically. Another concern is about the disconnection. Can all function calls in media_device_delete() be safe even if it's called while the application still opens the MC device?
Right. I have been looking into device removal path when ioctls are active and I can resolve any issues that might surface while an audio app is active when device is removed.
In anyway, such a thing can be improved later once after we get this merged, too. So, feel fee to take my ack.
Acked-by: Takashi Iwai tiwai@suse.de
thanks for the Ack -- Shuah
thanks,
Takashi