> This is added as a kselftest since unlike other ALSA test programs it does
> not require either physical setup of the device or interactive monitoring
what did you mean by 'not require physical setup of the device'?
> diff --git a/tools/testing/selftests/alsa/mixer-test.c b/tools/testing/selftests/alsa/mixer-test.c
> new file mode 100644
> index 000000000000..6082efa0b426
> --- /dev/null
> +++ b/tools/testing/selftests/alsa/mixer-test.c
> @@ -0,0 +1,616 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// kselftest for the ALSA mixer API
> +//
> +// Original author: Mark Brown <broonie@xxxxxxxxxx>
> +// Copyright (c) 2021 Arm Limited
> +
> +// This test will iterate over all cards detected in the system, exercising
would it make sense to test only specific cards? People doing automated
tests might have a USB device for capture of analog loopbacks, or
injection of specific streams for capture, and usually care about
testing such devices - which do need manual setups and wiring btw.
> + switch (snd_ctl_elem_info_get_type(ctl->info)) {
> + case SND_CTL_ELEM_TYPE_NONE:
> + ksft_print_msg("%s Invalid control type NONE\n", ctl->name);
> + err = -1;
> + break;
> +
> + case SND_CTL_ELEM_TYPE_BOOLEAN:
> + int_val = snd_ctl_elem_value_get_boolean(ctl->def_val, 0);
> + switch (int_val) {
> + case 0:
> + case 1:
> + break;
> + default:
> + ksft_print_msg("%s Invalid boolean value %ld\n",
> + ctl->name, int_val);
> + err = -1;
> + break;
> + }
> + break;
> +
> + case SND_CTL_ELEM_TYPE_INTEGER:
> + int_val = snd_ctl_elem_value_get_integer(ctl->def_val, 0);
> +
> + if (int_val < snd_ctl_elem_info_get_min(ctl->info)) {
> + ksft_print_msg("%s value %ld less than minimum %ld\n",
> + ctl->name, int_val,
> + snd_ctl_elem_info_get_min(ctl->info));
> + err = -1;
> + }
> +
> + if (int_val > snd_ctl_elem_info_get_max(ctl->info)) {
> + ksft_print_msg("%s value %ld more than maximum %ld\n",
> + ctl->name, int_val,
> + snd_ctl_elem_info_get_max(ctl->info));
> + err = -1;
> + }
> +
> + /* Only check step size if there is one and we're in bounds */
> + if (err >= 0 && snd_ctl_elem_info_get_step(ctl->info) &&
> + (int_val - snd_ctl_elem_info_get_min(ctl->info) %
> + snd_ctl_elem_info_get_step(ctl->info))) {
> + ksft_print_msg("%s value %ld invalid for step %ld minimum %ld\n",
> + ctl->name, int_val,
> + snd_ctl_elem_info_get_step(ctl->info),
> + snd_ctl_elem_info_get_min(ctl->info));
> + err = -1;
> + }
> + break;
> +
> + case SND_CTL_ELEM_TYPE_INTEGER64:
> + int64_val = snd_ctl_elem_value_get_integer64(ctl->def_val, 0);
> +
> + if (int64_val < snd_ctl_elem_info_get_min64(ctl->info)) {
> + ksft_print_msg("%s value %lld less than minimum %lld\n",
> + ctl->name, int64_val,
> + snd_ctl_elem_info_get_min64(ctl->info));
> + err = -1;
> + }
> +
> + if (int64_val > snd_ctl_elem_info_get_max64(ctl->info)) {
> + ksft_print_msg("%s value %lld more than maximum %lld\n",
> + ctl->name, int64_val,
> + snd_ctl_elem_info_get_max(ctl->info));
> + err = -1;
> + }
> +
> + /* Only check step size if there is one and we're in bounds */
> + if (err >= 0 && snd_ctl_elem_info_get_step64(ctl->info) &&
> + (int64_val - snd_ctl_elem_info_get_min64(ctl->info)) %
> + snd_ctl_elem_info_get_step64(ctl->info)) {
> + ksft_print_msg("%s value %lld invalid for step %lld minimum %lld\n",
> + ctl->name, int64_val,
> + snd_ctl_elem_info_get_step64(ctl->info),
> + snd_ctl_elem_info_get_min64(ctl->info));
> + err = -1;
> + }
> + break;
> +
> + default:
> + /* No tests for other types */
these types include ENUMERATED, BYTES and IEC958, but see below for
ENUMERATED...
> + ksft_test_result_skip("get_value.%d.%d\n",
> + ctl->card->card, ctl->elem);
> + return;
> + }
> +
> +out:
> + ksft_test_result(err >= 0, "get_value.%d.%d\n",
> + ctl->card->card, ctl->elem);
> +}
> +
> +bool show_mismatch(struct ctl_data *ctl, int index,
> + snd_ctl_elem_value_t *read_val,
> + snd_ctl_elem_value_t *expected_val)
> +{
> + long long expected_int, read_int;
> +
> + /*
> + * We factor out the code to compare values representable as
> + * integers, ensure that check doesn't log otherwise.
> + */
> + expected_int = 0;
> + read_int = 0;
> +
> + switch (snd_ctl_elem_info_get_type(ctl->info)) {
> + case SND_CTL_ELEM_TYPE_BOOLEAN:
> + expected_int = snd_ctl_elem_value_get_boolean(expected_val,
> + index);
> + read_int = snd_ctl_elem_value_get_boolean(read_val, index);
> + break;
> +
> + case SND_CTL_ELEM_TYPE_INTEGER:
> + expected_int = snd_ctl_elem_value_get_integer(expected_val,
> + index);
> + read_int = snd_ctl_elem_value_get_integer(read_val, index);
> + break;
> +
> + case SND_CTL_ELEM_TYPE_INTEGER64:
> + expected_int = snd_ctl_elem_value_get_integer64(expected_val,
> + index);
> + read_int = snd_ctl_elem_value_get_integer64(read_val,
> + index);
> + break;
> +
> + case SND_CTL_ELEM_TYPE_ENUMERATED:
... here you are handling ENUMERATED types?
> + expected_int = snd_ctl_elem_value_get_enumerated(expected_val,
> + index);
> + read_int = snd_ctl_elem_value_get_enumerated(read_val,
> + index);
> + break;
> +
> + default:
> + break;
> + }
> +
> + if (expected_int != read_int) {
> + ksft_print_msg("%s.%d expected %lld but read %lld\n",
> + ctl->name, index, expected_int, read_int);
> + return true;
> + } else {
> + return false;
> + }
> +}
