On 09/01/2015 11:53 AM, Clemens Ladisch wrote: > Shuah Khan wrote:> On 09/01/2015 02:42 AM, Clemens Ladisch wrote: >>> Shuah Khan wrote: >>>> +++ b/sound/usb/stream.c >>>> pcm->private_data = as; >>>> pcm->private_free = snd_usb_audio_pcm_free; >>>> pcm->info_flags = 0; >>>> + pcm->nonatomic = true; >>> >>> Why do you think you need nonatomic mode in the USB audio driver? >> >> I have been working on adding Media Controller support for this chip >> as chip specific feature in ALSA. This will allow sharing resources >> such as the tuner across the drivers that control the device (DVB, >> Video, snd-usb-audio). Media Controller framework uses a mutex to >> protect access to resources, hence there is a need to hold this mutex >> from SNDRV_PCM_TRIGGER_START and SNDRV_PCM_TRIGGER_STOP which could run >> in IRQ context. > > Resources should be managed in the hw_params/hw_free callbacks. > snd_usb_hw_params() and snd_usb_hw_free() are the two places I could add resource access logic and try if that works for what I am trying to do. Thanks for the tip. thanks, -- Shuah -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978 -- 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
