On Sat, 27 Feb 2016 03:55:39 +0100, Shuah Khan wrote: > > On 02/26/2016 01:50 PM, Takashi Iwai wrote: > > 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? > > Sorry my mistake. I misspoke. My config had: > CONFIG_MEDIA_SUPPORT=m > CONFIG_MEDIA_CONTROLLER=y > CONFIG_SND_USB_AUDIO=m > > The following doesn't work as you pointed out. > > CONFIG_MEDIA_SUPPORT=m > CONFIG_MEDIA_CONTROLLER=y > CONFIG_SND_USB_AUDIO=y > > okay here is what will work for all of the possible > combinations of CONFIG_MEDIA_SUPPORT and CONFIG_SND_USB_AUDIO > > select SND_USB_AUDIO_USE_MEDIA_CONTROLLER \ > if MEDIA_CONTROLLER && ((MEDIA_SUPPORT=y) || (MEDIA_SUPPORT=m && SND_USB_AUDIO=m)) > > The above will cover the cases when > > 1. CONFIG_MEDIA_SUPPORT and CONFIG_SND_USB_AUDIO are > both modules > CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER is selected > > 2. CONFIG_MEDIA_SUPPORT=y and CONFIG_SND_USB_AUDIO=m > CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER is selected > > 3. CONFIG_MEDIA_SUPPORT=y and CONFIG_SND_USB_AUDIO=y > CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER is selected > > 4. CONFIG_MEDIA_SUPPORT=m and CONFIG_SND_USB_AUDIO=y > This is when we don't want > CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER selected > > I verified all of the above combinations to make sure > the logic works. > > If you think of a better way to do this please let me > know. I will go ahead and send patch v4 with the above > change and you can decide if that is acceptable. I'm not 100% sure whether CONFIG_SND_USB_AUDIO=m can be put there as conditional inside CONFIG_SND_USB_AUDIO definition. Maybe a safer form would be like: config SND_USB_AUDIO_USE_MEDIA_CONTROLLER bool default y depends on SND_USB_AUDIO depends on MEDIA_CONTROLLER depends on (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND_USB_AUDIO) and drop select from SND_USB_AUDIO. > >>> 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? > > > > There is a known problem with device removal when > media device file is open and ioctl is in progress. > This isn't specific to this patch series, a general > problem that is related to media device removal in > general. > > I am working on a fix for this problem. As you said, > earlier, I can work on fixing issues after the merge. OK, understood. 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
