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SubjectRe: [PATCH v2 2/5] ALSA: xen-front: Read sound driver configuration from Xen store
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On 04/16/2018 03:55 PM, Juergen Gross wrote:
> On 16/04/18 08:24, Oleksandr Andrushchenko wrote:
>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>>
>> Read configuration values from Xen store according
>> to xen/interface/io/sndif.h protocol:
>> - introduce configuration structures for different
>> components, e.g. sound card, device, stream
>> - read PCM HW parameters, e.g rate, format etc.
>> - detect stream type (capture/playback)
>> - read device and card parameters
>>
>> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>> ---
>> sound/xen/Makefile | 3 +-
>> sound/xen/xen_snd_front.c | 7 +
>> sound/xen/xen_snd_front.h | 4 +
>> sound/xen/xen_snd_front_cfg.c | 517 ++++++++++++++++++++++++++++++++++++++++++
>> sound/xen/xen_snd_front_cfg.h | 46 ++++
>> 5 files changed, 576 insertions(+), 1 deletion(-)
>> create mode 100644 sound/xen/xen_snd_front_cfg.c
>> create mode 100644 sound/xen/xen_snd_front_cfg.h
>>
>> diff --git a/sound/xen/Makefile b/sound/xen/Makefile
>> index 4507ef3c27fd..06705bef61fa 100644
>> --- a/sound/xen/Makefile
>> +++ b/sound/xen/Makefile
>> @@ -1,5 +1,6 @@
>> # SPDX-License-Identifier: GPL-2.0 OR MIT
>>
>> -snd_xen_front-objs := xen_snd_front.o
>> +snd_xen_front-objs := xen_snd_front.o \
>> + xen_snd_front_cfg.o
>>
>> obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
>> diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
>> index f406a8f52c51..65d2494a9d14 100644
>> --- a/sound/xen/xen_snd_front.c
>> +++ b/sound/xen/xen_snd_front.c
>> @@ -25,6 +25,13 @@ static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
>>
>> static int sndback_initwait(struct xen_snd_front_info *front_info)
>> {
>> + int num_streams;
>> + int ret;
>> +
>> + ret = xen_snd_front_cfg_card(front_info, &num_streams);
>> + if (ret < 0)
>> + return ret;
>> +
>> return 0;
>> }
>>
>> diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h
>> index 4ae204b23d32..b52226cb30bc 100644
>> --- a/sound/xen/xen_snd_front.h
>> +++ b/sound/xen/xen_snd_front.h
>> @@ -11,8 +11,12 @@
>> #ifndef __XEN_SND_FRONT_H
>> #define __XEN_SND_FRONT_H
>>
>> +#include "xen_snd_front_cfg.h"
>> +
>> struct xen_snd_front_info {
>> struct xenbus_device *xb_dev;
>> +
>> + struct xen_front_cfg_card cfg;
>> };
>>
>> #endif /* __XEN_SND_FRONT_H */
>> diff --git a/sound/xen/xen_snd_front_cfg.c b/sound/xen/xen_snd_front_cfg.c
>> new file mode 100644
>> index 000000000000..d461985afffa
>> --- /dev/null
>> +++ b/sound/xen/xen_snd_front_cfg.c
>> @@ -0,0 +1,517 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>> +
>> +/*
>> + * Xen para-virtual sound device
>> + *
>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
>> + *
>> + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>> + */
>> +
>> +#include <xen/xenbus.h>
>> +
>> +#include <xen/interface/io/sndif.h>
>> +
>> +#include "xen_snd_front.h"
>> +#include "xen_snd_front_cfg.h"
>> +
>> +/* maximum number of supported streams */
> Comment style (multiple times below, too):
> Start with a capital letter and end sentences with a full stop.
will fix
>> +#define VSND_MAX_STREAM 8
>> +
>> +struct cfg_hw_sample_rate {
>> + const char *name;
>> + unsigned int mask;
>> + unsigned int value;
>> +};
>> +
>> +static const struct cfg_hw_sample_rate CFG_HW_SUPPORTED_RATES[] = {
>> + { .name = "5512", .mask = SNDRV_PCM_RATE_5512, .value = 5512 },
>> + { .name = "8000", .mask = SNDRV_PCM_RATE_8000, .value = 8000 },
>> + { .name = "11025", .mask = SNDRV_PCM_RATE_11025, .value = 11025 },
>> + { .name = "16000", .mask = SNDRV_PCM_RATE_16000, .value = 16000 },
>> + { .name = "22050", .mask = SNDRV_PCM_RATE_22050, .value = 22050 },
>> + { .name = "32000", .mask = SNDRV_PCM_RATE_32000, .value = 32000 },
>> + { .name = "44100", .mask = SNDRV_PCM_RATE_44100, .value = 44100 },
>> + { .name = "48000", .mask = SNDRV_PCM_RATE_48000, .value = 48000 },
>> + { .name = "64000", .mask = SNDRV_PCM_RATE_64000, .value = 64000 },
>> + { .name = "96000", .mask = SNDRV_PCM_RATE_96000, .value = 96000 },
>> + { .name = "176400", .mask = SNDRV_PCM_RATE_176400, .value = 176400 },
>> + { .name = "192000", .mask = SNDRV_PCM_RATE_192000, .value = 192000 },
>> +};
>> +
>> +struct cfg_hw_sample_format {
>> + const char *name;
>> + u64 mask;
>> +};
>> +
>> +static const struct cfg_hw_sample_format CFG_HW_SUPPORTED_FORMATS[] = {
>> + {
>> + .name = XENSND_PCM_FORMAT_U8_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U8
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S8_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S8
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U16_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U16_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U16_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U16_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S16_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S16_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S16_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S16_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U24_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U24_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U24_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U24_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S24_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S24_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S24_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S24_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U32_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U32_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_U32_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_U32_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S32_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S32_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_S32_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_S32_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_A_LAW_STR,
>> + .mask = SNDRV_PCM_FMTBIT_A_LAW
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_MU_LAW_STR,
>> + .mask = SNDRV_PCM_FMTBIT_MU_LAW
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_F32_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_FLOAT_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_F32_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_FLOAT_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_F64_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_FLOAT64_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_F64_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_FLOAT64_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR,
>> + .mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_IMA_ADPCM_STR,
>> + .mask = SNDRV_PCM_FMTBIT_IMA_ADPCM
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_MPEG_STR,
>> + .mask = SNDRV_PCM_FMTBIT_MPEG
>> + },
>> + {
>> + .name = XENSND_PCM_FORMAT_GSM_STR,
>> + .mask = SNDRV_PCM_FMTBIT_GSM
>> + },
>> +};
>> +
>> +static void cfg_hw_rates(char *list, unsigned int len,
>> + const char *path, struct snd_pcm_hardware *pcm_hw)
>> +{
>> + char *cur_rate;
>> + unsigned int cur_mask;
>> + unsigned int cur_value;
>> + unsigned int rates;
>> + unsigned int rate_min;
>> + unsigned int rate_max;
>> + int i;
>> +
>> + rates = 0;
>> + rate_min = -1;
>> + rate_max = 0;
>> + while ((cur_rate = strsep(&list, XENSND_LIST_SEPARATOR))) {
>> + for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_RATES); i++)
>> + if (!strncasecmp(cur_rate,
>> + CFG_HW_SUPPORTED_RATES[i].name,
>> + XENSND_SAMPLE_RATE_MAX_LEN)) {
>> + cur_mask = CFG_HW_SUPPORTED_RATES[i].mask;
>> + cur_value = CFG_HW_SUPPORTED_RATES[i].value;
>> + rates |= cur_mask;
>> + if (rate_min > cur_value)
>> + rate_min = cur_value;
>> + if (rate_max < cur_value)
>> + rate_max = cur_value;
>> + }
>> + }
>> +
>> + if (rates) {
>> + pcm_hw->rates = rates;
>> + pcm_hw->rate_min = rate_min;
>> + pcm_hw->rate_max = rate_max;
>> + }
>> +}
>> +
>> +static void cfg_formats(char *list, unsigned int len,
>> + const char *path, struct snd_pcm_hardware *pcm_hw)
>> +{
>> + u64 formats;
>> + char *cur_format;
>> + int i;
>> +
>> + formats = 0;
>> + while ((cur_format = strsep(&list, XENSND_LIST_SEPARATOR))) {
>> + for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_FORMATS); i++)
>> + if (!strncasecmp(cur_format,
>> + CFG_HW_SUPPORTED_FORMATS[i].name,
>> + XENSND_SAMPLE_FORMAT_MAX_LEN))
>> + formats |= CFG_HW_SUPPORTED_FORMATS[i].mask;
>> + }
>> +
>> + if (formats)
>> + pcm_hw->formats = formats;
>> +}
>> +
>> +#define MAX_BUFFER_SIZE (64 * 1024)
>> +#define MIN_PERIOD_SIZE 64
>> +#define MAX_PERIOD_SIZE MAX_BUFFER_SIZE
>> +#define USE_FORMATS (SNDRV_PCM_FMTBIT_U8 | \
>> + SNDRV_PCM_FMTBIT_S16_LE)
>> +#define USE_RATE (SNDRV_PCM_RATE_CONTINUOUS | \
>> + SNDRV_PCM_RATE_8000_48000)
>> +#define USE_RATE_MIN 5512
>> +#define USE_RATE_MAX 48000
>> +#define USE_CHANNELS_MIN 1
>> +#define USE_CHANNELS_MAX 2
>> +#define USE_PERIODS_MIN 2
>> +#define USE_PERIODS_MAX (MAX_BUFFER_SIZE / MIN_PERIOD_SIZE)
>> +
>> +static const struct snd_pcm_hardware SND_DRV_PCM_HW_DEFAULT = {
>> + .info = (SNDRV_PCM_INFO_MMAP |
>> + SNDRV_PCM_INFO_INTERLEAVED |
>> + SNDRV_PCM_INFO_RESUME |
>> + SNDRV_PCM_INFO_MMAP_VALID),
>> + .formats = USE_FORMATS,
>> + .rates = USE_RATE,
>> + .rate_min = USE_RATE_MIN,
>> + .rate_max = USE_RATE_MAX,
>> + .channels_min = USE_CHANNELS_MIN,
>> + .channels_max = USE_CHANNELS_MAX,
>> + .buffer_bytes_max = MAX_BUFFER_SIZE,
>> + .period_bytes_min = MIN_PERIOD_SIZE,
>> + .period_bytes_max = MAX_PERIOD_SIZE,
>> + .periods_min = USE_PERIODS_MIN,
>> + .periods_max = USE_PERIODS_MAX,
>> + .fifo_size = 0,
>> +};
>> +
>> +static void cfg_read_pcm_hw(const char *path,
>> + struct snd_pcm_hardware *parent_pcm_hw,
>> + struct snd_pcm_hardware *pcm_hw)
>> +{
>> + char *list;
>> + int val;
>> + size_t buf_sz;
>> + unsigned int len;
>> +
>> + /* inherit parent's PCM HW and read overrides from XenStore */
>> + if (parent_pcm_hw)
>> + *pcm_hw = *parent_pcm_hw;
>> + else
>> + *pcm_hw = SND_DRV_PCM_HW_DEFAULT;
>> +
>> + val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MIN, 0);
>> + if (val)
>> + pcm_hw->channels_min = val;
>> +
>> + val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MAX, 0);
>> + if (val)
>> + pcm_hw->channels_max = val;
>> +
>> + list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_RATES, &len);
>> + if (!IS_ERR(list)) {
>> + cfg_hw_rates(list, len, path, pcm_hw);
>> + kfree(list);
>> + }
>> +
>> + list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_FORMATS, &len);
>> + if (!IS_ERR(list)) {
>> + cfg_formats(list, len, path, pcm_hw);
>> + kfree(list);
>> + }
>> +
>> + buf_sz = xenbus_read_unsigned(path, XENSND_FIELD_BUFFER_SIZE, 0);
>> + if (buf_sz)
>> + pcm_hw->buffer_bytes_max = buf_sz;
>> +
>> + /* update configuration to match new values */
>> + if (pcm_hw->channels_min > pcm_hw->channels_max)
>> + pcm_hw->channels_min = pcm_hw->channels_max;
>> +
>> + if (pcm_hw->rate_min > pcm_hw->rate_max)
>> + pcm_hw->rate_min = pcm_hw->rate_max;
>> +
>> + pcm_hw->period_bytes_max = pcm_hw->buffer_bytes_max;
>> +
>> + pcm_hw->periods_max = pcm_hw->period_bytes_max /
>> + pcm_hw->period_bytes_min;
>> +}
>> +
>> +static int cfg_get_stream_type(const char *path, int index,
>> + int *num_pb, int *num_cap)
>> +{
>> + char *str = NULL;
>> + char *stream_path;
>> + int ret;
>> +
>> + *num_pb = 0;
>> + *num_cap = 0;
>> + stream_path = kasprintf(GFP_KERNEL, "%s/%d", path, index);
>> + if (!stream_path) {
>> + ret = -ENOMEM;
>> + goto fail;
>> + }
>> +
>> + str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);
>> + if (IS_ERR(str)) {
>> + ret = -EINVAL;
> Is this correct? Do you want to return -EINVAL in case xenbus_read()
> failed with e.g. -ENOMEM?
will return PTR_ERR(str)
>> + goto fail;
>> + }
>> +
>> + if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,
>> + sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {
>> + (*num_pb)++;
>> + } else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,
>> + sizeof(XENSND_STREAM_TYPE_CAPTURE))) {
>> + (*num_cap)++;
>> + } else {
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> + ret = 0;
>> +
>> +fail:
>> + kfree(stream_path);
>> + kfree(str);
>> + return ret;
>> +}
>> +
>> +static int cfg_stream(struct xen_snd_front_info *front_info,
>> + struct xen_front_cfg_pcm_instance *pcm_instance,
>> + const char *path, int index, int *cur_pb, int *cur_cap,
>> + int *stream_cnt)
>> +{
>> + char *str = NULL;
>> + char *stream_path;
>> + struct xen_front_cfg_stream *stream;
>> + int ret;
>> +
>> + stream_path = devm_kasprintf(&front_info->xb_dev->dev,
>> + GFP_KERNEL, "%s/%d", path, index);
>> + if (!stream_path) {
>> + ret = -ENOMEM;
>> + goto fail;
>> + }
>> +
>> + str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);
>> + if (IS_ERR(str)) {
>> + ret = -EINVAL;
> Same as above.
will return PTR_ERR(str)
>
>> + goto fail;
>> + }
>> +
>> + if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,
>> + sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {
>> + stream = &pcm_instance->streams_pb[(*cur_pb)++];
>> + } else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,
>> + sizeof(XENSND_STREAM_TYPE_CAPTURE))) {
>> + stream = &pcm_instance->streams_cap[(*cur_cap)++];
>> + } else {
>> + ret = -EINVAL;
>> + goto fail;
>> + }
> Until here this function looks very much like cfg_get_stream_type().
> Can't they use a common sub-function?
Not really, because cfg_get_stream_type uses kasprintf
for strings and this one devm_kasprintf. Trying to make
a common sub-func doesn't make sense to me
>
>> +
>> + /* get next stream index */
>> + stream->index = (*stream_cnt)++;
>> + stream->xenstore_path = stream_path;
>> + /*
>> + * check in Xen store if PCM HW configuration exists for this stream
>> + * and update if so, e.g. we inherit all values from device's PCM HW,
>> + * but can still override some of the values for the stream
>> + */
>> + cfg_read_pcm_hw(stream->xenstore_path,
>> + &pcm_instance->pcm_hw, &stream->pcm_hw);
>> + ret = 0;
>> +
>> +fail:
>> + kfree(str);
>> + return ret;
>> +}
>> +
>> +static int cfg_device(struct xen_snd_front_info *front_info,
>> + struct xen_front_cfg_pcm_instance *pcm_instance,
>> + struct snd_pcm_hardware *parent_pcm_hw,
>> + const char *path, int node_index, int *stream_cnt)
>> +{
>> + char *str;
>> + char *device_path;
>> + int ret, i, num_streams;
>> + int num_pb, num_cap;
>> + int cur_pb, cur_cap;
>> + char node[3];
>> +
>> + device_path = kasprintf(GFP_KERNEL, "%s/%d", path, node_index);
>> + if (!device_path)
>> + return -ENOMEM;
>> +
>> + str = xenbus_read(XBT_NIL, device_path, XENSND_FIELD_DEVICE_NAME, NULL);
>> + if (!IS_ERR(str)) {
>> + strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));
>> + kfree(str);
>> + }
>> +
>> + pcm_instance->device_id = node_index;
>> +
>> + /*
>> + * check in Xen store if PCM HW configuration exists for this device
>> + * and update if so, e.g. we inherit all values from card's PCM HW,
>> + * but can still override some of the values for the device
>> + */
>> + cfg_read_pcm_hw(device_path, parent_pcm_hw, &pcm_instance->pcm_hw);
>> +
>> + /* find out how many streams were configured in Xen store */
>> + num_streams = 0;
>> + do {
>> + snprintf(node, sizeof(node), "%d", num_streams);
>> + if (!xenbus_exists(XBT_NIL, device_path, node))
>> + break;
>> +
>> + num_streams++;
>> + } while (num_streams < VSND_MAX_STREAM);
>> +
>> + pcm_instance->num_streams_pb = 0;
>> + pcm_instance->num_streams_cap = 0;
>> + /* get number of playback and capture streams */
>> + for (i = 0; i < num_streams; i++) {
>> + ret = cfg_get_stream_type(device_path, i, &num_pb, &num_cap);
>> + if (ret < 0)
>> + goto fail;
>> +
>> + pcm_instance->num_streams_pb += num_pb;
>> + pcm_instance->num_streams_cap += num_cap;
>> + }
>> +
>> + if (pcm_instance->num_streams_pb) {
>> + pcm_instance->streams_pb =
>> + devm_kcalloc(&front_info->xb_dev->dev,
>> + pcm_instance->num_streams_pb,
>> + sizeof(struct xen_front_cfg_stream),
>> + GFP_KERNEL);
>> + if (!pcm_instance->streams_pb) {
>> + ret = -ENOMEM;
>> + goto fail;
>> + }
>> + }
>> +
>> + if (pcm_instance->num_streams_cap) {
>> + pcm_instance->streams_cap =
>> + devm_kcalloc(&front_info->xb_dev->dev,
>> + pcm_instance->num_streams_cap,
>> + sizeof(struct xen_front_cfg_stream),
>> + GFP_KERNEL);
>> + if (!pcm_instance->streams_cap) {
>> + ret = -ENOMEM;
>> + goto fail;
>> + }
>> + }
>> +
>> + cur_pb = 0;
>> + cur_cap = 0;
>> + for (i = 0; i < num_streams; i++) {
>> + ret = cfg_stream(front_info, pcm_instance, device_path, i,
>> + &cur_pb, &cur_cap, stream_cnt);
>> + if (ret < 0)
>> + goto fail;
>> + }
>> + ret = 0;
>> +
>> +fail:
>> + kfree(device_path);
>> + return ret;
>> +}
>> +
>> +int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,
>> + int *stream_cnt)
>> +{
>> + struct xenbus_device *xb_dev = front_info->xb_dev;
>> + struct xen_front_cfg_card *cfg = &front_info->cfg;
>> + int ret, num_devices, i;
>> + char node[3];
>> +
>> + *stream_cnt = 0;
>> + num_devices = 0;
>> + do {
>> + snprintf(node, sizeof(node), "%d", num_devices);
>> + if (!xenbus_exists(XBT_NIL, xb_dev->nodename, node))
>> + break;
>> +
>> + num_devices++;
>> + } while (num_devices < SNDRV_PCM_DEVICES);
>> +
>> + if (!num_devices) {
>> + dev_warn(&xb_dev->dev,
>> + "No devices configured for sound card at %s\n",
>> + xb_dev->nodename);
>> + return -ENODEV;
>> + }
>> +
>> + /* start from default PCM HW configuration for the card */
>> + cfg_read_pcm_hw(xb_dev->nodename, NULL, &cfg->pcm_hw);
>> +
>> + cfg->pcm_instances =
>> + devm_kcalloc(&front_info->xb_dev->dev, num_devices,
>> + sizeof(struct xen_front_cfg_pcm_instance),
>> + GFP_KERNEL);
>> + if (!cfg->pcm_instances)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < num_devices; i++) {
>> + ret = cfg_device(front_info, &cfg->pcm_instances[i],
>> + &cfg->pcm_hw, xb_dev->nodename, i, stream_cnt);
>> + if (ret < 0)
>> + return ret;
> Who will free all the memory allocated until now in case of an error?
The memory is allocated with devm_xxx functions, so it will
be freed on device destructions automatically
>
> And I think when removing the device freeing the memory is missing, too.
Same as above, the kernel will take care of it while destroying the device
>
> Juergen

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