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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "alsa_device_profile"
     18 /*#define LOG_NDEBUG 0*/
     19 /*#define LOG_PCM_PARAMS 0*/
     20 
     21 #include <errno.h>
     22 #include <inttypes.h>
     23 #include <stdint.h>
     24 #include <stdlib.h>
     25 #include <cutils/properties.h>
     26 
     27 #include <log/log.h>
     28 
     29 #include "include/alsa_device_profile.h"
     30 #include "include/alsa_format.h"
     31 #include "include/alsa_logging.h"
     32 
     33 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
     34 
     35 #define PERIOD_DURATION_US (5 * 1000)
     36 
     37 #define DEFAULT_PERIOD_SIZE 1024
     38 
     39 static const char * const format_string_map[] = {
     40     "AUDIO_FORMAT_PCM_16_BIT",      /* "PCM_FORMAT_S16_LE", */
     41     "AUDIO_FORMAT_PCM_32_BIT",      /* "PCM_FORMAT_S32_LE", */
     42     "AUDIO_FORMAT_PCM_8_BIT",       /* "PCM_FORMAT_S8", */
     43     "AUDIO_FORMAT_PCM_8_24_BIT",    /* "PCM_FORMAT_S24_LE", */
     44     "AUDIO_FORMAT_PCM_24_BIT_PACKED"/* "PCM_FORMAT_S24_3LE" */
     45 };
     46 
     47 extern int8_t const pcm_format_value_map[50];
     48 
     49 /* Sort these in terms of preference (best first).
     50    192 kHz is not first because it requires significant resources for possibly worse
     51    quality and driver instability (depends on device).
     52    The order here determines the default sample rate for the device.
     53    AudioPolicyManager may not respect this ordering when picking sample rates.
     54    Update MAX_PROFILE_SAMPLE_RATES after changing the array size.
     55 
     56    TODO: remove 32000, 22050, 12000, 11025?  Each sample rate check
     57    requires opening the device which may cause pops. */
     58 static const unsigned std_sample_rates[] =
     59     {96000, 88200, 192000, 176400, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000};
     60 
     61 static void profile_reset(alsa_device_profile* profile)
     62 {
     63     profile->card = profile->device = -1;
     64 
     65     /* terminate the attribute arrays with invalid values */
     66     profile->formats[0] = PCM_FORMAT_INVALID;
     67     profile->sample_rates[0] = 0;
     68     profile->channel_counts[0] = 0;
     69 
     70     profile->min_period_size = profile->max_period_size = 0;
     71     profile->min_channel_count = profile->max_channel_count = DEFAULT_CHANNEL_COUNT;
     72 
     73     profile->is_valid = false;
     74 }
     75 
     76 void profile_init(alsa_device_profile* profile, int direction)
     77 {
     78     profile->direction = direction;
     79     profile_reset(profile);
     80 }
     81 
     82 bool profile_is_initialized(alsa_device_profile* profile)
     83 {
     84     return profile->card >= 0 && profile->device >= 0;
     85 }
     86 
     87 bool profile_is_valid(alsa_device_profile* profile) {
     88     return profile->is_valid;
     89 }
     90 
     91 bool profile_is_cached_for(alsa_device_profile* profile, int card, int device) {
     92     return card == profile->card && device == profile->device;
     93 }
     94 
     95 void profile_decache(alsa_device_profile* profile) {
     96     profile_reset(profile);
     97 }
     98 
     99 /*
    100  * Returns the supplied value rounded up to the next even multiple of 16
    101  */
    102 static unsigned int round_to_16_mult(unsigned int size)
    103 {
    104     return (size + 15) & ~15;   /* 0xFFFFFFF0; */
    105 }
    106 
    107 /*
    108  * Returns the system defined minimum period size based on the supplied sample rate.
    109  */
    110 unsigned profile_calc_min_period_size(alsa_device_profile* profile, unsigned sample_rate)
    111 {
    112     ALOGV("profile_calc_min_period_size(%p, rate:%d)", profile, sample_rate);
    113     if (profile == NULL) {
    114         return DEFAULT_PERIOD_SIZE;
    115     } else {
    116         unsigned period_us = property_get_int32("ro.audio.usb.period_us", PERIOD_DURATION_US);
    117         unsigned num_sample_frames = ((uint64_t)sample_rate * period_us) / 1000000;
    118 
    119         if (num_sample_frames < profile->min_period_size) {
    120             num_sample_frames = profile->min_period_size;
    121         }
    122         return round_to_16_mult(num_sample_frames);
    123     }
    124 }
    125 
    126 unsigned int profile_get_period_size(alsa_device_profile* profile, unsigned sample_rate)
    127 {
    128     unsigned int period_size = profile_calc_min_period_size(profile, sample_rate);
    129     ALOGV("profile_get_period_size(rate:%d) = %d", sample_rate, period_size);
    130     return period_size;
    131 }
    132 
    133 /*
    134  * Sample Rate
    135  */
    136 unsigned profile_get_default_sample_rate(alsa_device_profile* profile)
    137 {
    138     /*
    139      * TODO this won't be right in general. we should store a preferred rate as we are scanning.
    140      * But right now it will return the highest rate, which may be correct.
    141      */
    142     return profile_is_valid(profile) ? profile->sample_rates[0] : DEFAULT_SAMPLE_RATE;
    143 }
    144 
    145 bool profile_is_sample_rate_valid(alsa_device_profile* profile, unsigned rate)
    146 {
    147     if (profile_is_valid(profile)) {
    148         size_t index;
    149         for (index = 0; profile->sample_rates[index] != 0; index++) {
    150             if (profile->sample_rates[index] == rate) {
    151                 return true;
    152             }
    153         }
    154 
    155         return false;
    156     } else {
    157         return rate == DEFAULT_SAMPLE_RATE;
    158     }
    159 }
    160 
    161 /*
    162  * Format
    163  */
    164 enum pcm_format profile_get_default_format(alsa_device_profile* profile)
    165 {
    166     /*
    167      * TODO this won't be right in general. we should store a preferred format as we are scanning.
    168      */
    169     return profile_is_valid(profile) ? profile->formats[0] : DEFAULT_SAMPLE_FORMAT;
    170 }
    171 
    172 bool profile_is_format_valid(alsa_device_profile* profile, enum pcm_format fmt) {
    173     if (profile_is_valid(profile)) {
    174         size_t index;
    175         for (index = 0; profile->formats[index] != PCM_FORMAT_INVALID; index++) {
    176             if (profile->formats[index] == fmt) {
    177                 return true;
    178             }
    179         }
    180 
    181         return false;
    182     } else {
    183         return fmt == DEFAULT_SAMPLE_FORMAT;
    184     }
    185 }
    186 
    187 /*
    188  * Channels
    189  */
    190 unsigned profile_get_default_channel_count(alsa_device_profile* profile)
    191 {
    192     return profile_is_valid(profile) ? profile->channel_counts[0] : DEFAULT_CHANNEL_COUNT;
    193 }
    194 
    195 unsigned profile_get_closest_channel_count(alsa_device_profile* profile, unsigned count)
    196 {
    197     if (profile_is_valid(profile)) {
    198         if (count < profile->min_channel_count) {
    199             return profile->min_channel_count;
    200         } else if (count > profile->max_channel_count) {
    201             return profile->max_channel_count;
    202         } else {
    203             return count;
    204         }
    205     } else {
    206         return 0;
    207     }
    208 }
    209 
    210 bool profile_is_channel_count_valid(alsa_device_profile* profile, unsigned count)
    211 {
    212     if (profile_is_initialized(profile)) {
    213         return count >= profile->min_channel_count && count <= profile->max_channel_count;
    214     } else {
    215         return count == DEFAULT_CHANNEL_COUNT;
    216     }
    217 }
    218 
    219 static bool profile_test_sample_rate(alsa_device_profile* profile, unsigned rate)
    220 {
    221     struct pcm_config config = profile->default_config;
    222     config.rate = rate;
    223 
    224     bool works = false; /* let's be pessimistic */
    225     struct pcm * pcm = pcm_open(profile->card, profile->device,
    226                                 profile->direction, &config);
    227 
    228     if (pcm != NULL) {
    229         works = pcm_is_ready(pcm);
    230         pcm_close(pcm);
    231     }
    232 
    233     return works;
    234 }
    235 
    236 static unsigned profile_enum_sample_rates(alsa_device_profile* profile, unsigned min, unsigned max)
    237 {
    238     unsigned num_entries = 0;
    239     unsigned index;
    240 
    241     for (index = 0; index < ARRAY_SIZE(std_sample_rates) &&
    242                     num_entries < ARRAY_SIZE(profile->sample_rates) - 1;
    243          index++) {
    244         if (std_sample_rates[index] >= min && std_sample_rates[index] <= max
    245                 && profile_test_sample_rate(profile, std_sample_rates[index])) {
    246             profile->sample_rates[num_entries++] = std_sample_rates[index];
    247         }
    248     }
    249     profile->sample_rates[num_entries] = 0; /* terminate */
    250     return num_entries; /* return # of supported rates */
    251 }
    252 
    253 static unsigned profile_enum_sample_formats(alsa_device_profile* profile, struct pcm_mask * mask)
    254 {
    255     const int num_slots = ARRAY_SIZE(mask->bits);
    256     const int bits_per_slot = sizeof(mask->bits[0]) * 8;
    257 
    258     const int table_size = ARRAY_SIZE(pcm_format_value_map);
    259 
    260     int slot_index, bit_index, table_index;
    261     table_index = 0;
    262     int num_written = 0;
    263     for (slot_index = 0; slot_index < num_slots && table_index < table_size;
    264             slot_index++) {
    265         unsigned bit_mask = 1;
    266         for (bit_index = 0;
    267                 bit_index < bits_per_slot && table_index < table_size;
    268                 bit_index++) {
    269             if ((mask->bits[slot_index] & bit_mask) != 0) {
    270                 enum pcm_format format = pcm_format_value_map[table_index];
    271                 /* Never return invalid (unrecognized) or 8-bit */
    272                 if (format != PCM_FORMAT_INVALID && format != PCM_FORMAT_S8) {
    273                     profile->formats[num_written++] = format;
    274                     if (num_written == ARRAY_SIZE(profile->formats) - 1) {
    275                         /* leave at least one PCM_FORMAT_INVALID at the end */
    276                         goto end;
    277                     }
    278                 }
    279             }
    280             bit_mask <<= 1;
    281             table_index++;
    282         }
    283     }
    284 end:
    285     profile->formats[num_written] = PCM_FORMAT_INVALID;
    286     return num_written;
    287 }
    288 
    289 static unsigned profile_enum_channel_counts(alsa_device_profile* profile, unsigned min,
    290         unsigned max)
    291 {
    292     /* modify alsa_device_profile.h if you change the std_channel_counts[] array. */
    293     static const unsigned std_channel_counts[] = {8, 7, 6, 5, 4, 3, 2, 1};
    294 
    295     unsigned num_counts = 0;
    296     unsigned index;
    297     /* TODO write a profile_test_channel_count() */
    298     /* Ensure there is at least one invalid channel count to terminate the channel counts array */
    299     for (index = 0; index < ARRAY_SIZE(std_channel_counts) &&
    300                     num_counts < ARRAY_SIZE(profile->channel_counts) - 1;
    301          index++) {
    302         /* TODO Do we want a channel counts test? */
    303         if (std_channel_counts[index] >= min && std_channel_counts[index] <= max /* &&
    304             profile_test_channel_count(profile, channel_counts[index])*/) {
    305             profile->channel_counts[num_counts++] = std_channel_counts[index];
    306         }
    307     }
    308     // if we have no match with the standard counts, we use the largest (preferred) std count.
    309     if (num_counts == 0) {
    310         ALOGW("usb device does not match std channel counts, setting to %d",
    311                 std_channel_counts[0]);
    312         profile->channel_counts[num_counts++] = std_channel_counts[0];
    313     }
    314     profile->channel_counts[num_counts] = 0;
    315     return num_counts; /* return # of supported counts */
    316 }
    317 
    318 /*
    319  * Reads and decodes configuration info from the specified ALSA card/device.
    320  */
    321 static int read_alsa_device_config(alsa_device_profile * profile, struct pcm_config * config)
    322 {
    323     ALOGV("usb:audio_hw - read_alsa_device_config(c:%d d:%d t:0x%X)",
    324           profile->card, profile->device, profile->direction);
    325 
    326     if (profile->card < 0 || profile->device < 0) {
    327         return -EINVAL;
    328     }
    329 
    330     struct pcm_params * alsa_hw_params =
    331         pcm_params_get(profile->card, profile->device, profile->direction);
    332     if (alsa_hw_params == NULL) {
    333         return -EINVAL;
    334     }
    335 
    336     profile->min_period_size = pcm_params_get_min(alsa_hw_params, PCM_PARAM_PERIOD_SIZE);
    337     profile->max_period_size = pcm_params_get_max(alsa_hw_params, PCM_PARAM_PERIOD_SIZE);
    338 
    339     profile->min_channel_count = pcm_params_get_min(alsa_hw_params, PCM_PARAM_CHANNELS);
    340     profile->max_channel_count = pcm_params_get_max(alsa_hw_params, PCM_PARAM_CHANNELS);
    341 
    342     int ret = 0;
    343 
    344     /*
    345      * This Logging will be useful when testing new USB devices.
    346      */
    347 #ifdef LOG_PCM_PARAMS
    348     log_pcm_params(alsa_hw_params);
    349 #endif
    350 
    351     config->channels = pcm_params_get_min(alsa_hw_params, PCM_PARAM_CHANNELS);
    352     // For output devices, let's make sure we choose at least stereo
    353     // (assuming the device supports it).
    354     if (profile->direction == PCM_OUT &&
    355         config->channels < 2 && pcm_params_get_max(alsa_hw_params, PCM_PARAM_CHANNELS) >= 2) {
    356         config->channels = 2;
    357     }
    358     config->rate = pcm_params_get_min(alsa_hw_params, PCM_PARAM_RATE);
    359     // Prefer 48K or 44.1K
    360     if (config->rate < 48000 &&
    361         pcm_params_get_max(alsa_hw_params, PCM_PARAM_RATE) >= 48000) {
    362         config->rate = 48000;
    363     } else if (config->rate < 441000 &&
    364                pcm_params_get_max(alsa_hw_params, PCM_PARAM_RATE) >= 44100) {
    365         config->rate = 44100;
    366     }
    367     config->period_size = profile_calc_min_period_size(profile, config->rate);
    368     config->period_count = pcm_params_get_min(alsa_hw_params, PCM_PARAM_PERIODS);
    369     config->format = get_pcm_format_for_mask(pcm_params_get_mask(alsa_hw_params, PCM_PARAM_FORMAT));
    370 #ifdef LOG_PCM_PARAMS
    371     log_pcm_config(config, "read_alsa_device_config");
    372 #endif
    373     if (config->format == PCM_FORMAT_INVALID) {
    374         ret = -EINVAL;
    375     }
    376 
    377     pcm_params_free(alsa_hw_params);
    378 
    379     return ret;
    380 }
    381 
    382 bool profile_read_device_info(alsa_device_profile* profile)
    383 {
    384     if (!profile_is_initialized(profile)) {
    385         return false;
    386     }
    387 
    388     /* let's get some defaults */
    389     read_alsa_device_config(profile, &profile->default_config);
    390     ALOGV("default_config chans:%d rate:%d format:%d count:%d size:%d",
    391           profile->default_config.channels, profile->default_config.rate,
    392           profile->default_config.format, profile->default_config.period_count,
    393           profile->default_config.period_size);
    394 
    395     struct pcm_params * alsa_hw_params = pcm_params_get(profile->card,
    396                                                         profile->device,
    397                                                         profile->direction);
    398     if (alsa_hw_params == NULL) {
    399         return false;
    400     }
    401 
    402     /* Formats */
    403     struct pcm_mask * format_mask = pcm_params_get_mask(alsa_hw_params, PCM_PARAM_FORMAT);
    404     profile_enum_sample_formats(profile, format_mask);
    405 
    406     /* Channels */
    407     profile_enum_channel_counts(
    408             profile, pcm_params_get_min(alsa_hw_params, PCM_PARAM_CHANNELS),
    409             pcm_params_get_max(alsa_hw_params, PCM_PARAM_CHANNELS));
    410 
    411     /* Sample Rates */
    412     profile_enum_sample_rates(
    413             profile, pcm_params_get_min(alsa_hw_params, PCM_PARAM_RATE),
    414             pcm_params_get_max(alsa_hw_params, PCM_PARAM_RATE));
    415 
    416     profile->is_valid = true;
    417 
    418     return true;
    419 }
    420 
    421 char * profile_get_sample_rate_strs(alsa_device_profile* profile)
    422 {
    423     /* if we assume that rate strings are about 5 characters (48000 is 5), plus ~1 for a
    424      * delimiter "|" this buffer has room for about 22 rate strings which seems like
    425      * way too much, but it's a stack variable so only temporary.
    426      */
    427     char buffer[128];
    428     buffer[0] = '\0';
    429     size_t buffSize = ARRAY_SIZE(buffer);
    430     size_t curStrLen = 0;
    431 
    432     char numBuffer[32];
    433 
    434     size_t numEntries = 0;
    435     size_t index;
    436     for (index = 0; profile->sample_rates[index] != 0; index++) {
    437         snprintf(numBuffer, sizeof(numBuffer), "%u", profile->sample_rates[index]);
    438         // account for both the null, and potentially the bar.
    439         if (buffSize - curStrLen < strlen(numBuffer) + (numEntries != 0 ? 2 : 1)) {
    440             /* we don't have room for another, so bail at this point rather than
    441              * return a malformed rate string
    442              */
    443             break;
    444         }
    445         if (numEntries++ != 0) {
    446             strlcat(buffer, "|", buffSize);
    447         }
    448         curStrLen = strlcat(buffer, numBuffer, buffSize);
    449     }
    450 
    451     return strdup(buffer);
    452 }
    453 
    454 char * profile_get_format_strs(alsa_device_profile* profile)
    455 {
    456     /* if we assume that format strings are about 24 characters (AUDIO_FORMAT_PCM_16_BIT is 23),
    457      * plus ~1 for a delimiter "|" this buffer has room for about 10 format strings which seems
    458      *  like way too much, but it's a stack variable so only temporary.
    459      */
    460     char buffer[256];
    461     buffer[0] = '\0';
    462     size_t buffSize = ARRAY_SIZE(buffer);
    463     size_t curStrLen = 0;
    464 
    465     size_t numEntries = 0;
    466     size_t index = 0;
    467     for (index = 0; profile->formats[index] != PCM_FORMAT_INVALID; index++) {
    468         // account for both the null, and potentially the bar.
    469         if (buffSize - curStrLen < strlen(format_string_map[profile->formats[index]])
    470                                    + (numEntries != 0 ? 2 : 1)) {
    471             /* we don't have room for another, so bail at this point rather than
    472              * return a malformed rate string
    473              */
    474             break;
    475         }
    476         if (numEntries++ != 0) {
    477             strlcat(buffer, "|", buffSize);
    478         }
    479         curStrLen = strlcat(buffer, format_string_map[profile->formats[index]], buffSize);
    480     }
    481 
    482     return strdup(buffer);
    483 }
    484 
    485 char * profile_get_channel_count_strs(alsa_device_profile* profile)
    486 {
    487     // FIXME implicit fixed channel count assumption here (FCC_8).
    488     // we use only the canonical even number channel position masks.
    489     static const char * const out_chans_strs[] = {
    490         /* 0 */"AUDIO_CHANNEL_NONE", /* will never be taken as this is a terminator */
    491         /* 1 */"AUDIO_CHANNEL_OUT_MONO",
    492         /* 2 */"AUDIO_CHANNEL_OUT_STEREO",
    493         /* 3 */ /* "AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_FRONT_CENTER" */ NULL,
    494         /* 4 */"AUDIO_CHANNEL_OUT_QUAD",
    495         /* 5 */ /* "AUDIO_CHANNEL_OUT_QUAD|AUDIO_CHANNEL_OUT_FRONT_CENTER" */ NULL,
    496         /* 6 */"AUDIO_CHANNEL_OUT_5POINT1",
    497         /* 7 */ /* "AUDIO_CHANNEL_OUT_5POINT1|AUDIO_CHANNEL_OUT_BACK_CENTER" */ NULL,
    498         /* 8 */"AUDIO_CHANNEL_OUT_7POINT1",
    499         /* channel counts greater than this not considered */
    500     };
    501 
    502     static const char * const in_chans_strs[] = {
    503         /* 0 */"AUDIO_CHANNEL_NONE", /* will never be taken as this is a terminator */
    504         /* 1 */"AUDIO_CHANNEL_IN_MONO",
    505         /* 2 */"AUDIO_CHANNEL_IN_STEREO",
    506         /* channel counts greater than this not considered */
    507     };
    508 
    509     static const char * const index_chans_strs[] = {
    510         /* 0 */"AUDIO_CHANNEL_NONE", /* will never be taken as this is a terminator */
    511         /* 1 */"AUDIO_CHANNEL_INDEX_MASK_1",
    512         /* 2 */"AUDIO_CHANNEL_INDEX_MASK_2",
    513         /* 3 */"AUDIO_CHANNEL_INDEX_MASK_3",
    514         /* 4 */"AUDIO_CHANNEL_INDEX_MASK_4",
    515         /* 5 */"AUDIO_CHANNEL_INDEX_MASK_5",
    516         /* 6 */"AUDIO_CHANNEL_INDEX_MASK_6",
    517         /* 7 */"AUDIO_CHANNEL_INDEX_MASK_7",
    518         /* 8 */"AUDIO_CHANNEL_INDEX_MASK_8",
    519     };
    520 
    521     const bool isOutProfile = profile->direction == PCM_OUT;
    522 
    523     const char * const * const chans_strs = isOutProfile ? out_chans_strs : in_chans_strs;
    524     const size_t chans_strs_size =
    525             isOutProfile ? ARRAY_SIZE(out_chans_strs) : ARRAY_SIZE(in_chans_strs);
    526 
    527     /*
    528      * If we assume each channel string is 26 chars ("AUDIO_CHANNEL_INDEX_MASK_8" is 26) + 1 for,
    529      * the "|" delimiter, then we allocate room for 16 strings.
    530      */
    531     char buffer[27 * 16 + 1]; /* caution, may need to be expanded */
    532     buffer[0] = '\0';
    533     size_t buffSize = ARRAY_SIZE(buffer);
    534     size_t curStrLen = 0;
    535 
    536     /* We currently support MONO and STEREO, and always report STEREO but some (many)
    537      * USB Audio Devices may only announce support for MONO (a headset mic for example), or
    538      * The total number of output channels. SO, if the device itself doesn't explicitly
    539      * support STEREO, append to the channel config strings we are generating.
    540      *
    541      * The MONO and STEREO positional channel masks are provided for legacy compatibility.
    542      * For multichannel (n > 2) we only expose channel index masks.
    543      */
    544     // Always support stereo
    545     curStrLen = strlcat(buffer, chans_strs[2], buffSize);
    546 
    547     size_t index;
    548     unsigned channel_count;
    549     for (index = 0;
    550          (channel_count = profile->channel_counts[index]) != 0;
    551          index++) {
    552 
    553         /* we only show positional information for mono (stereo handled already) */
    554         if (channel_count < chans_strs_size
    555                 && chans_strs[channel_count] != NULL
    556                 && channel_count < 2 /* positional only for fewer than 2 channels */) {
    557             // account for the '|' and the '\0'
    558             if (buffSize - curStrLen < strlen(chans_strs[channel_count]) + 2) {
    559                 /* we don't have room for another, so bail at this point rather than
    560                  * return a malformed rate string
    561                  */
    562                 break;
    563             }
    564 
    565             strlcat(buffer, "|", buffSize);
    566             curStrLen = strlcat(buffer, chans_strs[channel_count], buffSize);
    567         }
    568 
    569         // handle channel index masks for both input and output
    570         // +2 to account for the '|' and the '\0'
    571          if (buffSize - curStrLen < strlen(index_chans_strs[channel_count]) + 2) {
    572              /* we don't have room for another, so bail at this point rather than
    573               * return a malformed rate string
    574               */
    575              break;
    576          }
    577 
    578          strlcat(buffer, "|", buffSize);
    579          curStrLen = strlcat(buffer, index_chans_strs[channel_count], buffSize);
    580     }
    581 
    582     return strdup(buffer);
    583 }
    584 
    585 void profile_dump(const alsa_device_profile* profile, int fd)
    586 {
    587     if (profile == NULL) {
    588         dprintf(fd, "  %s\n", "No USB Profile");
    589         return; /* bail early */
    590     }
    591 
    592     if (!profile->is_valid) {
    593         dprintf(fd, "  Profile is INVALID");
    594     }
    595 
    596     /* card/device/direction */
    597     dprintf(fd, "  card:%d, device:%d - %s\n",
    598                 profile->card, profile->device, profile->direction == PCM_OUT ? "OUT" : "IN");
    599 
    600     /* formats */
    601     dprintf(fd, "  Formats: ");
    602     for (int fmtIndex = 0;
    603           profile->formats[fmtIndex] != PCM_FORMAT_INVALID && fmtIndex < MAX_PROFILE_FORMATS;
    604           fmtIndex++) {
    605         dprintf(fd, "%d ", profile->formats[fmtIndex]);
    606     }
    607     dprintf(fd, "\n");
    608 
    609     /* sample rates */
    610     dprintf(fd, "  Rates: ");
    611     for (int rateIndex = 0;
    612           profile->sample_rates[rateIndex] != 0 && rateIndex < MAX_PROFILE_SAMPLE_RATES;
    613           rateIndex++) {
    614         dprintf(fd, "%u ", profile->sample_rates[rateIndex]);
    615     }
    616     dprintf(fd, "\n");
    617 
    618     // channel counts
    619     dprintf(fd, "  Channel Counts: ");
    620     for (int cntIndex = 0;
    621           profile->channel_counts[cntIndex] != 0 && cntIndex < MAX_PROFILE_CHANNEL_COUNTS;
    622           cntIndex++) {
    623         dprintf(fd, "%u ", profile->channel_counts[cntIndex]);
    624     }
    625     dprintf(fd, "\n");
    626 
    627     dprintf(fd, "  min/max period size [%u : %u]\n",
    628             profile->min_period_size,profile-> max_period_size);
    629     dprintf(fd, "  min/max channel count [%u : %u]\n",
    630             profile->min_channel_count, profile->max_channel_count);
    631 
    632     // struct pcm_config default_config;
    633     dprintf(fd, "  Default Config:\n");
    634     dprintf(fd, "    channels: %d\n", profile->default_config.channels);
    635     dprintf(fd, "    rate: %d\n", profile->default_config.rate);
    636     dprintf(fd, "    period_size: %d\n", profile->default_config.period_size);
    637     dprintf(fd, "    period_count: %d\n", profile->default_config.period_count);
    638     dprintf(fd, "    format: %d\n", profile->default_config.format);
    639 }
    640