On Fri, 26 Feb 2016 21:08:43 +0100, Shuah Khan wrote: > > 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@xxxxxxxxxxxxxxx> > >> --- > >> 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. Hmm, how does it be? In drivers/media/Makefile: ifeq ($(CONFIG_MEDIA_CONTROLLER),y) obj-$(CONFIG_MEDIA_SUPPORT) += media.o endif So it's a module. Meanwhile you have reference from usb-audio driver that is built-in kernel. How is the symbol resolved? > 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. So, it's 100% safe to call all these media_*() functions while the device is being accessed before closing? Takashi -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
