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.
Regards, Clemens