TinyAlsa: audio device identification

Description

TinyAlsa fails to identify the right audio card/device (always pcmC0D0p that does not exist ). No sound

Expected behavior

TinyAlsa picks up an existing device amongst:

ls -lha /dev/snd/pcm*
crw-rw----+ 1 root audio 116, 6 Jan 28 09:59 /dev/snd/pcmC0D10p
crw-rw----+ 1 root audio 116, 2 Jan 28 09:59 /dev/snd/pcmC0D3p
crw-rw----+ 1 root audio 116, 3 Jan 28 09:59 /dev/snd/pcmC0D7p
crw-rw----+ 1 root audio 116, 4 Jan 28 09:59 /dev/snd/pcmC0D8p
crw-rw----+ 1 root audio 116, 5 Jan 28 09:59 /dev/snd/pcmC0D9p
crw-rw----+ 1 root audio 116, 10 Jan 28 09:59 /dev/snd/pcmC1D0c
crw-rw----+ 1 root audio 116, 9 Jan 28 18:30 /dev/snd/pcmC1D0p
crw-rw----+ 1 root audio 116, 11 Jan 28 09:57 /dev/snd/pcmC1D2c

Actual behavior

Compilation is okay:

grep -i audio log
Checking presence of predefined macro AUDIO_SETINFO in sys/audioio.h ... no
Checking existence of -lossaudio ... no
CC libretro-common/audio/resampler/audio_resampler.c
CC libretro-common/audio/dsp_filter.c
CC libretro-common/audio/resampler/drivers/sinc_resampler.c
CC libretro-common/audio/resampler/drivers/nearest_resampler.c
CC tasks/task_audio_mixer.c
CC libretro-common/audio/audio_mix.c
CC libretro-common/audio/audio_mixer.c
CC audio/drivers_resampler/cc_resampler.c
CC audio/drivers/oss.c
CC audio/drivers/tinyalsa.c
CC libretro-common/audio/conversion/s16_to_float.c
CC libretro-common/audio/conversion/float_to_s16.c
CC audio/audio_thread_wrapper.c

During runtime:

[ERROR] [TINYALSA]: params: Cannot open audio device.
[ERROR] [TINYALSA]: Failed to initialize tinyalsa driver.
cannot open device '/dev/snd/pcmC0D0p'

Steps to reproduce the bug

1. ./configure
2. make
3. ./retroarch

Bisect Results

N/A. I compiled from commits involving changes in audio/drivers/tinyalsa.c. Tinyalsa always selects pcmC0D0p

Version/Commit

• RetroArch: d0a2315098

Environment information

• OS: Ubuntu 18.04.3 LTS
• Compiler: gcc 7.4.0

Start with audio/drivers/tinyalsa.c and reproduce the reported device-selection failure using ./configure, make, and ./retroarch. Compare the device path it selects with the available /dev/snd/pcm* entries and the runtime error. Done means TinyAlsa selects an existing audio device and initializes without the reported error.