[PATCH v3 3/3] kselftest: alsa: Use private alsa-lib configuration in mixer test

[Shuah Khan]

On 12/8/21 2:17 PM, Mark Brown wrote:
> From: Jaroslav Kysela <perex at perex.cz>
> 
> As mentined by Takashi Sakamoto, the system-wide alsa-lib configuration
> may override the standard device declarations. This patch use the private
> alsa-lib configuration to set the predictable environment.
> 
> Signed-off-by: Jaroslav Kysela <perex at perex.cz>
> Link: https://lore.kernel.org/r/20211208095209.1772296-1-perex@perex.cz
> [Restructure version test to keep the preprocessor happy -- broonie]
> Signed-off-by: Mark Brown <broonie at kernel.org>
> ---
>   tools/testing/selftests/alsa/mixer-test.c | 56 ++++++++++++++++++++++-
>   1 file changed, 55 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/alsa/mixer-test.c b/tools/testing/selftests/alsa/mixer-test.c
> index 171d33692c7b..a177676c530e 100644
> --- a/tools/testing/selftests/alsa/mixer-test.c
> +++ b/tools/testing/selftests/alsa/mixer-test.c
> @@ -46,22 +46,74 @@ struct ctl_data {
>   	struct ctl_data *next;
>   };
>   
> +static const char *alsa_config =
> +"ctl.hw {\n"
> +"	@args [ CARD ]\n"
> +"	@args.CARD.type string\n"
> +"	type hw\n"
> +"	card $CARD\n"
> +"}\n"
> +;
> +
>   int num_cards = 0;
>   int num_controls = 0;
>   struct card_data *card_list = NULL;
>   struct ctl_data *ctl_list = NULL;
>   
> +#ifdef SND_LIB_VER
> +#if SND_LIB_VERSION >= SND_LIB_VER(1, 2, 6)
> +#define LIB_HAS_LOAD_STRING
> +#endif
> +#endif
> +
> +#ifndef LIB_HAS_LOAD_STRING
> +int snd_config_load_string(snd_config_t **config, const char *s, size_t size)
> +{
> +	snd_input_t *input;
> +	snd_config_t *dst;
> +	int err;
> +
> +	assert(config && s);
> +	if (size == 0)
> +		size = strlen(s);
> +	err = snd_input_buffer_open(&input, s, size);
> +	if (err < 0)
> +		return err;
> +	err = snd_config_top(&dst);
> +	if (err < 0) {
> +		snd_input_close(input);
> +		return err;
> +	}
> +	err = snd_config_load(dst, input);
> +	snd_input_close(input);
> +	if (err < 0) {
> +		snd_config_delete(dst);
> +		return err;
> +	}
> +	*config = dst;
> +	return 0;

Why not consolidate the error path code?

> +}
> +#endif
> +
>   void find_controls(void)
>   {
>   	char name[32];
>   	int card, ctl, err;
>   	struct card_data *card_data;
>   	struct ctl_data *ctl_data;
> +	snd_config_t *config;
>   
>   	card = -1;
>   	if (snd_card_next(&card) < 0 || card < 0)
>   		return;
>   
> +	err = snd_config_load_string(&config, alsa_config, strlen(alsa_config));
> +	if (err < 0) {
> +		ksft_print_msg("Unable to parse custom alsa-lib configuration: %s\n",
> +			       snd_strerror(err));
> +		ksft_exit_fail();
> +	}
> +
>   	while (card >= 0) {
>   		sprintf(name, "hw:%d", card);
>   
> @@ -69,7 +121,7 @@ void find_controls(void)
>   		if (!card_data)
>   			ksft_exit_fail_msg("Out of memory\n");
>   
> -		err = snd_ctl_open(&card_data->handle, name, 0);
> +		err = snd_ctl_open_lconf(&card_data->handle, name, 0, config);
>   		if (err < 0) {
>   			ksft_print_msg("Failed to get hctl for card %d: %s\n",
>   				       card, snd_strerror(err));
> @@ -137,6 +189,8 @@ void find_controls(void)
>   			break;
>   		}
>   	}
> +
> +	snd_config_delete(config);
>   }
>   
>   /*

This open comment at the end of the patch looks odd. Does this compile?

> 

thanks
-- Shuah