* [PATCH 1/2] pcm: add mmap_begin callback to snd_pcm_fast_ops_t api
2019-05-23 13:00 [PATCH 0/2] add pcm_file support in MMAP read access mode Adam Miartus
@ 2019-05-23 13:00 ` Adam Miartus
2019-05-23 13:00 ` [PATCH 2/2] pcm_file: add infile read support for mmap mode Adam Miartus
2019-05-24 9:17 ` [ALSA patch] [PATCH 0/2] add pcm_file support in MMAP read access mode Takashi Iwai
2 siblings, 0 replies; 4+ messages in thread
From: Adam Miartus @ 2019-05-23 13:00 UTC (permalink / raw)
To: patch; +Cc: alsa-devel
main motivation for adding the callback is to use it to enable operation
on mmaped buffer before user access for pcm_file plugin
support for MMAP read access with masking by data from input file is not
implemented for pcm_file plugin, by adding this callback implementing
such feature can be done by rewriting next continuous portion of buffer
on each mmap_begin call
plugins like softvol use pcm_plugin interface and overwrite the buffer by
looping around it in avail_update callback, this patch hopes to simplify
the task by adding new api callback, removing the need for rewriting
pcm_file (to use pcm_plugin callbacks) and careful checking when looping
around whole mmaped buffer
Signed-off-by: Adam Miartus <amiartus@de.adit-jv.com>
Reviewed-by: Timo Wischer <twischer@de.adit-jv.com>
---
src/pcm/pcm.c | 6 ++++++
src/pcm/pcm_local.h | 1 +
2 files changed, 7 insertions(+)
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index 3a71d79..323926e 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -7129,7 +7129,13 @@ int __snd_pcm_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas,
snd_pcm_uframes_t f;
snd_pcm_uframes_t avail;
const snd_pcm_channel_area_t *xareas;
+
assert(pcm && areas && offset && frames);
+
+ if (pcm->fast_ops->mmap_begin)
+ return pcm->fast_ops->mmap_begin(pcm->fast_op_arg, areas, offset, frames);
+
+ /* fallback for plugins that do not specify new callback */
xareas = snd_pcm_mmap_areas(pcm);
if (xareas == NULL)
return -EBADFD;
diff --git a/src/pcm/pcm_local.h b/src/pcm/pcm_local.h
index d52229d..d5726eb 100644
--- a/src/pcm/pcm_local.h
+++ b/src/pcm/pcm_local.h
@@ -184,6 +184,7 @@ typedef struct {
int (*poll_descriptors)(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int space); /* locked */
int (*poll_revents)(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int nfds, unsigned short *revents); /* locked */
int (*may_wait_for_avail_min)(snd_pcm_t *pcm, snd_pcm_uframes_t avail);
+ int (*mmap_begin)(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas, snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames); /* locked */
} snd_pcm_fast_ops_t;
struct _snd_pcm {
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] pcm_file: add infile read support for mmap mode
2019-05-23 13:00 [PATCH 0/2] add pcm_file support in MMAP read access mode Adam Miartus
2019-05-23 13:00 ` [PATCH 1/2] pcm: add mmap_begin callback to snd_pcm_fast_ops_t api Adam Miartus
@ 2019-05-23 13:00 ` Adam Miartus
2019-05-24 9:17 ` [ALSA patch] [PATCH 0/2] add pcm_file support in MMAP read access mode Takashi Iwai
2 siblings, 0 replies; 4+ messages in thread
From: Adam Miartus @ 2019-05-23 13:00 UTC (permalink / raw)
To: patch; +Cc: alsa-devel
mmap_begin callback is used to copy data from input file to mmaped
buffer
guard for corner use of api (multiple mmap_begin calls by user) is
introduced to check if next continuous buffer was already overwritten
buffer is overwritten with input file data only in case of stream capture
Signed-off-by: Adam Miartus <amiartus@de.adit-jv.com>
Reviewed-by: Timo Wischer <twischer@de.adit-jv.com>
---
src/pcm/pcm_file.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c
index 8e2c70b..52cc10a 100644
--- a/src/pcm/pcm_file.c
+++ b/src/pcm/pcm_file.c
@@ -88,6 +88,7 @@ typedef struct {
size_t buffer_bytes;
struct wav_fmt wav_header;
size_t filelen;
+ char ifmmap_overwritten;
} snd_pcm_file_t;
#if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -630,6 +631,8 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm,
const snd_pcm_channel_area_t *areas;
snd_pcm_sframes_t result;
+ file->ifmmap_overwritten = 0;
+
result = snd_pcm_mmap_begin(file->gen.slave, &areas, &ofs, &siz);
if (result >= 0) {
assert(ofs == offset && siz == size);
@@ -640,6 +643,32 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm,
return result;
}
+static int snd_pcm_file_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas,
+ snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames)
+{
+ snd_pcm_file_t *file = pcm->private_data;
+ snd_pcm_channel_area_t areas_if[pcm->channels];
+ snd_pcm_uframes_t frames_if;
+ void *buffer = NULL;
+ int result;
+
+ result = snd_pcm_mmap_begin(file->gen.slave, areas, offset, frames);
+ if (result < 0)
+ return result;
+
+ if (pcm->stream != SND_PCM_STREAM_CAPTURE)
+ return result;
+
+ /* user may run mmap_begin without mmap_commit multiple times in row */
+ if (file->ifmmap_overwritten)
+ return result;
+ file->ifmmap_overwritten = 1;
+
+ snd_pcm_file_areas_read_infile(pcm, *areas, *offset, *frames);
+
+ return result;
+}
+
static int snd_pcm_file_hw_free(snd_pcm_t *pcm)
{
snd_pcm_file_t *file = pcm->private_data;
@@ -666,6 +695,7 @@ static int snd_pcm_file_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
file->wbuf_size = slave->buffer_size * 2;
file->wbuf_size_bytes = snd_pcm_frames_to_bytes(slave, file->wbuf_size);
file->wbuf_used_bytes = 0;
+ file->ifmmap_overwritten = 0;
assert(!file->wbuf);
file->wbuf = malloc(file->wbuf_size_bytes);
if (file->wbuf == NULL) {
@@ -777,6 +807,7 @@ static const snd_pcm_fast_ops_t snd_pcm_file_fast_ops = {
.poll_descriptors = snd_pcm_generic_poll_descriptors,
.poll_revents = snd_pcm_generic_poll_revents,
.htimestamp = snd_pcm_generic_htimestamp,
+ .mmap_begin = snd_pcm_file_mmap_begin,
};
/**
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread