freebsd-skq/sys/dev/sound/pcm/buffer.c
mav 68b6eb44b6 Make sound(4) more flexible in setting soft buffer and block sizes when
hardware imposes strict limitations on hard buffer and block sizes.

Previous code set soft buffer to be no smaller then hard buffer. On some
cards with fixed 64K physical buffer that caused up to 800ms play latency.
New code allows to set soft buffer size down to just two blocks of the hard
buffer and to not write more then that size ahead to the hardware buffer.
As result of that change I was able to reduce full practically measured
record-playback loop delay in those conditions down to only about 115ms
with theoretical playback latency of only about 50ms.

New code works fine for both vchans and direct cases. In both cases sound(4)
tries to follow hw.snd.latency_profile and hw.snd.latency values and
application-requested buffer and block sizes as much as limitation of two
hardware blocks allows.

Reviewed by:	silence on multimedia@
2012-01-31 21:46:28 +00:00

803 lines
17 KiB
C

/*-
* Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
* Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
* Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif
#include <dev/sound/pcm/sound.h>
#include "feeder_if.h"
#define SND_USE_FXDIV
#include "snd_fxdiv_gen.h"
SND_DECLARE_FILE("$FreeBSD$");
struct snd_dbuf *
sndbuf_create(device_t dev, char *drv, char *desc, struct pcm_channel *channel)
{
struct snd_dbuf *b;
b = malloc(sizeof(*b), M_DEVBUF, M_WAITOK | M_ZERO);
snprintf(b->name, SNDBUF_NAMELEN, "%s:%s", drv, desc);
b->dev = dev;
b->channel = channel;
return b;
}
void
sndbuf_destroy(struct snd_dbuf *b)
{
sndbuf_free(b);
free(b, M_DEVBUF);
}
bus_addr_t
sndbuf_getbufaddr(struct snd_dbuf *buf)
{
return (buf->buf_addr);
}
static void
sndbuf_setmap(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
struct snd_dbuf *b = (struct snd_dbuf *)arg;
if (bootverbose) {
device_printf(b->dev, "sndbuf_setmap %lx, %lx; ",
(u_long)segs[0].ds_addr, (u_long)segs[0].ds_len);
printf("%p -> %lx\n", b->buf, (u_long)segs[0].ds_addr);
}
if (error == 0)
b->buf_addr = segs[0].ds_addr;
else
b->buf_addr = 0;
}
/*
* Allocate memory for DMA buffer. If the device does not use DMA transfers,
* the driver can call malloc(9) and sndbuf_setup() itself.
*/
int
sndbuf_alloc(struct snd_dbuf *b, bus_dma_tag_t dmatag, int dmaflags,
unsigned int size)
{
int ret;
b->dmatag = dmatag;
b->dmaflags = dmaflags | BUS_DMA_NOWAIT | BUS_DMA_COHERENT;
b->maxsize = size;
b->bufsize = b->maxsize;
b->buf_addr = 0;
b->flags |= SNDBUF_F_MANAGED;
if (bus_dmamem_alloc(b->dmatag, (void **)&b->buf, b->dmaflags,
&b->dmamap)) {
sndbuf_free(b);
return (ENOMEM);
}
if (bus_dmamap_load(b->dmatag, b->dmamap, b->buf, b->maxsize,
sndbuf_setmap, b, 0) != 0 || b->buf_addr == 0) {
sndbuf_free(b);
return (ENOMEM);
}
ret = sndbuf_resize(b, 2, b->maxsize / 2);
if (ret != 0)
sndbuf_free(b);
return (ret);
}
int
sndbuf_setup(struct snd_dbuf *b, void *buf, unsigned int size)
{
b->flags &= ~SNDBUF_F_MANAGED;
if (buf)
b->flags |= SNDBUF_F_MANAGED;
b->buf = buf;
b->maxsize = size;
b->bufsize = b->maxsize;
return sndbuf_resize(b, 2, b->maxsize / 2);
}
void
sndbuf_free(struct snd_dbuf *b)
{
if (b->tmpbuf)
free(b->tmpbuf, M_DEVBUF);
if (b->shadbuf)
free(b->shadbuf, M_DEVBUF);
if (b->buf) {
if (b->flags & SNDBUF_F_MANAGED) {
if (b->dmamap)
bus_dmamap_unload(b->dmatag, b->dmamap);
if (b->dmatag)
bus_dmamem_free(b->dmatag, b->buf, b->dmamap);
} else
free(b->buf, M_DEVBUF);
}
b->tmpbuf = NULL;
b->shadbuf = NULL;
b->buf = NULL;
b->sl = 0;
b->dmatag = NULL;
b->dmamap = NULL;
}
#define SNDBUF_CACHE_SHIFT 5
int
sndbuf_resize(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
{
unsigned int bufsize, allocsize;
u_int8_t *tmpbuf;
CHN_LOCK(b->channel);
if (b->maxsize == 0)
goto out;
if (blkcnt == 0)
blkcnt = b->blkcnt;
if (blksz == 0)
blksz = b->blksz;
if (blkcnt < 2 || blksz < 16 || (blkcnt * blksz) > b->maxsize) {
CHN_UNLOCK(b->channel);
return EINVAL;
}
if (blkcnt == b->blkcnt && blksz == b->blksz)
goto out;
bufsize = blkcnt * blksz;
if (bufsize > b->allocsize ||
bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
allocsize = round_page(bufsize);
CHN_UNLOCK(b->channel);
tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
CHN_LOCK(b->channel);
if (snd_verbose > 3)
printf("%s(): b=%p %p -> %p [%d -> %d : %d]\n",
__func__, b, b->tmpbuf, tmpbuf,
b->allocsize, allocsize, bufsize);
if (b->tmpbuf != NULL)
free(b->tmpbuf, M_DEVBUF);
b->tmpbuf = tmpbuf;
b->allocsize = allocsize;
} else if (snd_verbose > 3)
printf("%s(): b=%p %d [%d] NOCHANGE\n",
__func__, b, b->allocsize, b->bufsize);
b->blkcnt = blkcnt;
b->blksz = blksz;
b->bufsize = bufsize;
sndbuf_reset(b);
out:
CHN_UNLOCK(b->channel);
return 0;
}
int
sndbuf_remalloc(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
{
unsigned int bufsize, allocsize;
u_int8_t *buf, *tmpbuf, *shadbuf;
if (blkcnt < 2 || blksz < 16)
return EINVAL;
bufsize = blksz * blkcnt;
if (bufsize > b->allocsize ||
bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
allocsize = round_page(bufsize);
CHN_UNLOCK(b->channel);
buf = malloc(allocsize, M_DEVBUF, M_WAITOK);
tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
shadbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
CHN_LOCK(b->channel);
if (b->buf != NULL)
free(b->buf, M_DEVBUF);
b->buf = buf;
if (b->tmpbuf != NULL)
free(b->tmpbuf, M_DEVBUF);
b->tmpbuf = tmpbuf;
if (b->shadbuf != NULL)
free(b->shadbuf, M_DEVBUF);
b->shadbuf = shadbuf;
if (snd_verbose > 3)
printf("%s(): b=%p %d -> %d [%d]\n",
__func__, b, b->allocsize, allocsize, bufsize);
b->allocsize = allocsize;
} else if (snd_verbose > 3)
printf("%s(): b=%p %d [%d] NOCHANGE\n",
__func__, b, b->allocsize, b->bufsize);
b->blkcnt = blkcnt;
b->blksz = blksz;
b->bufsize = bufsize;
b->maxsize = bufsize;
b->sl = bufsize;
sndbuf_reset(b);
return 0;
}
/**
* @brief Zero out space in buffer free area
*
* This function clears a chunk of @c length bytes in the buffer free area
* (i.e., where the next write will be placed).
*
* @param b buffer context
* @param length number of bytes to blank
*/
void
sndbuf_clear(struct snd_dbuf *b, unsigned int length)
{
int i;
u_char data, *p;
if (length == 0)
return;
if (length > b->bufsize)
length = b->bufsize;
data = sndbuf_zerodata(b->fmt);
i = sndbuf_getfreeptr(b);
p = sndbuf_getbuf(b);
while (length > 0) {
p[i] = data;
length--;
i++;
if (i >= b->bufsize)
i = 0;
}
}
/**
* @brief Zap buffer contents, resetting "ready area" fields
*
* @param b buffer context
*/
void
sndbuf_fillsilence(struct snd_dbuf *b)
{
if (b->bufsize > 0)
memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
b->rp = 0;
b->rl = b->bufsize;
}
void
sndbuf_fillsilence_rl(struct snd_dbuf *b, u_int rl)
{
if (b->bufsize > 0)
memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
b->rp = 0;
b->rl = min(b->bufsize, rl);
}
/**
* @brief Reset buffer w/o flushing statistics
*
* This function just zeroes out buffer contents and sets the "ready length"
* to zero. This was originally to facilitate minimal playback interruption
* (i.e., dropped samples) in SNDCTL_DSP_SILENCE/SKIP ioctls.
*
* @param b buffer context
*/
void
sndbuf_softreset(struct snd_dbuf *b)
{
b->rl = 0;
if (b->buf && b->bufsize > 0)
sndbuf_clear(b, b->bufsize);
}
void
sndbuf_reset(struct snd_dbuf *b)
{
b->hp = 0;
b->rp = 0;
b->rl = 0;
b->dl = 0;
b->prev_total = 0;
b->total = 0;
b->xrun = 0;
if (b->buf && b->bufsize > 0)
sndbuf_clear(b, b->bufsize);
sndbuf_clearshadow(b);
}
u_int32_t
sndbuf_getfmt(struct snd_dbuf *b)
{
return b->fmt;
}
int
sndbuf_setfmt(struct snd_dbuf *b, u_int32_t fmt)
{
b->fmt = fmt;
b->bps = AFMT_BPS(b->fmt);
b->align = AFMT_ALIGN(b->fmt);
#if 0
b->bps = AFMT_CHANNEL(b->fmt);
if (b->fmt & AFMT_16BIT)
b->bps <<= 1;
else if (b->fmt & AFMT_24BIT)
b->bps *= 3;
else if (b->fmt & AFMT_32BIT)
b->bps <<= 2;
#endif
return 0;
}
unsigned int
sndbuf_getspd(struct snd_dbuf *b)
{
return b->spd;
}
void
sndbuf_setspd(struct snd_dbuf *b, unsigned int spd)
{
b->spd = spd;
}
unsigned int
sndbuf_getalign(struct snd_dbuf *b)
{
return (b->align);
}
unsigned int
sndbuf_getblkcnt(struct snd_dbuf *b)
{
return b->blkcnt;
}
void
sndbuf_setblkcnt(struct snd_dbuf *b, unsigned int blkcnt)
{
b->blkcnt = blkcnt;
}
unsigned int
sndbuf_getblksz(struct snd_dbuf *b)
{
return b->blksz;
}
void
sndbuf_setblksz(struct snd_dbuf *b, unsigned int blksz)
{
b->blksz = blksz;
}
unsigned int
sndbuf_getbps(struct snd_dbuf *b)
{
return b->bps;
}
void *
sndbuf_getbuf(struct snd_dbuf *b)
{
return b->buf;
}
void *
sndbuf_getbufofs(struct snd_dbuf *b, unsigned int ofs)
{
KASSERT(ofs < b->bufsize, ("%s: ofs invalid %d", __func__, ofs));
return b->buf + ofs;
}
unsigned int
sndbuf_getsize(struct snd_dbuf *b)
{
return b->bufsize;
}
unsigned int
sndbuf_getmaxsize(struct snd_dbuf *b)
{
return b->maxsize;
}
unsigned int
sndbuf_getallocsize(struct snd_dbuf *b)
{
return b->allocsize;
}
unsigned int
sndbuf_runsz(struct snd_dbuf *b)
{
return b->dl;
}
void
sndbuf_setrun(struct snd_dbuf *b, int go)
{
b->dl = go? b->blksz : 0;
}
struct selinfo *
sndbuf_getsel(struct snd_dbuf *b)
{
return &b->sel;
}
/************************************************************/
unsigned int
sndbuf_getxrun(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->xrun;
}
void
sndbuf_setxrun(struct snd_dbuf *b, unsigned int xrun)
{
SNDBUF_LOCKASSERT(b);
b->xrun = xrun;
}
unsigned int
sndbuf_gethwptr(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->hp;
}
void
sndbuf_sethwptr(struct snd_dbuf *b, unsigned int ptr)
{
SNDBUF_LOCKASSERT(b);
b->hp = ptr;
}
unsigned int
sndbuf_getready(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
return b->rl;
}
unsigned int
sndbuf_getreadyptr(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
return b->rp;
}
unsigned int
sndbuf_getfree(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
return b->bufsize - b->rl;
}
unsigned int
sndbuf_getfreeptr(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
return (b->rp + b->rl) % b->bufsize;
}
u_int64_t
sndbuf_getblocks(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->total / b->blksz;
}
u_int64_t
sndbuf_getprevblocks(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->prev_total / b->blksz;
}
u_int64_t
sndbuf_gettotal(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->total;
}
u_int64_t
sndbuf_getprevtotal(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
return b->prev_total;
}
void
sndbuf_updateprevtotal(struct snd_dbuf *b)
{
SNDBUF_LOCKASSERT(b);
b->prev_total = b->total;
}
unsigned int
sndbuf_xbytes(unsigned int v, struct snd_dbuf *from, struct snd_dbuf *to)
{
if (from == NULL || to == NULL || v == 0)
return 0;
return snd_xbytes(v, sndbuf_getalign(from) * sndbuf_getspd(from),
sndbuf_getalign(to) * sndbuf_getspd(to));
}
u_int8_t
sndbuf_zerodata(u_int32_t fmt)
{
if (fmt & (AFMT_SIGNED | AFMT_PASSTHROUGH))
return (0x00);
else if (fmt & AFMT_MU_LAW)
return (0x7f);
else if (fmt & AFMT_A_LAW)
return (0x55);
return (0x80);
}
/************************************************************/
/**
* @brief Acquire buffer space to extend ready area
*
* This function extends the ready area length by @c count bytes, and may
* optionally copy samples from another location stored in @c from. The
* counter @c snd_dbuf::total is also incremented by @c count bytes.
*
* @param b audio buffer
* @param from sample source (optional)
* @param count number of bytes to acquire
*
* @retval 0 Unconditional
*/
int
sndbuf_acquire(struct snd_dbuf *b, u_int8_t *from, unsigned int count)
{
int l;
KASSERT(count <= sndbuf_getfree(b), ("%s: count %d > free %d", __func__, count, sndbuf_getfree(b)));
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
b->total += count;
if (from != NULL) {
while (count > 0) {
l = min(count, sndbuf_getsize(b) - sndbuf_getfreeptr(b));
bcopy(from, sndbuf_getbufofs(b, sndbuf_getfreeptr(b)), l);
from += l;
b->rl += l;
count -= l;
}
} else
b->rl += count;
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
return 0;
}
/**
* @brief Dispose samples from channel buffer, increasing size of ready area
*
* This function discards samples from the supplied buffer by advancing the
* ready area start pointer and decrementing the ready area length. If
* @c to is not NULL, then the discard samples will be copied to the location
* it points to.
*
* @param b PCM channel sound buffer
* @param to destination buffer (optional)
* @param count number of bytes to discard
*
* @returns 0 unconditionally
*/
int
sndbuf_dispose(struct snd_dbuf *b, u_int8_t *to, unsigned int count)
{
int l;
KASSERT(count <= sndbuf_getready(b), ("%s: count %d > ready %d", __func__, count, sndbuf_getready(b)));
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
if (to != NULL) {
while (count > 0) {
l = min(count, sndbuf_getsize(b) - sndbuf_getreadyptr(b));
bcopy(sndbuf_getbufofs(b, sndbuf_getreadyptr(b)), to, l);
to += l;
b->rl -= l;
b->rp = (b->rp + l) % b->bufsize;
count -= l;
}
} else {
b->rl -= count;
b->rp = (b->rp + count) % b->bufsize;
}
KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
return 0;
}
#ifdef SND_DIAGNOSTIC
static uint32_t snd_feeder_maxfeed = 0;
SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxfeed, CTLFLAG_RD,
&snd_feeder_maxfeed, 0, "maximum feeder count request");
static uint32_t snd_feeder_maxcycle = 0;
SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxcycle, CTLFLAG_RD,
&snd_feeder_maxcycle, 0, "maximum feeder cycle");
#endif
/* count is number of bytes we want added to destination buffer */
int
sndbuf_feed(struct snd_dbuf *from, struct snd_dbuf *to, struct pcm_channel *channel, struct pcm_feeder *feeder, unsigned int count)
{
unsigned int cnt, maxfeed;
#ifdef SND_DIAGNOSTIC
unsigned int cycle;
if (count > snd_feeder_maxfeed)
snd_feeder_maxfeed = count;
cycle = 0;
#endif
KASSERT(count > 0, ("can't feed 0 bytes"));
if (sndbuf_getfree(to) < count)
return (EINVAL);
maxfeed = SND_FXROUND(SND_FXDIV_MAX, sndbuf_getalign(to));
do {
cnt = FEEDER_FEED(feeder, channel, to->tmpbuf,
min(count, maxfeed), from);
if (cnt == 0)
break;
sndbuf_acquire(to, to->tmpbuf, cnt);
count -= cnt;
#ifdef SND_DIAGNOSTIC
cycle++;
#endif
} while (count != 0);
#ifdef SND_DIAGNOSTIC
if (cycle > snd_feeder_maxcycle)
snd_feeder_maxcycle = cycle;
#endif
return (0);
}
/************************************************************/
void
sndbuf_dump(struct snd_dbuf *b, char *s, u_int32_t what)
{
printf("%s: [", s);
if (what & 0x01)
printf(" bufsize: %d, maxsize: %d", b->bufsize, b->maxsize);
if (what & 0x02)
printf(" dl: %d, rp: %d, rl: %d, hp: %d", b->dl, b->rp, b->rl, b->hp);
if (what & 0x04)
printf(" total: %ju, prev_total: %ju, xrun: %d", (uintmax_t)b->total, (uintmax_t)b->prev_total, b->xrun);
if (what & 0x08)
printf(" fmt: 0x%x, spd: %d", b->fmt, b->spd);
if (what & 0x10)
printf(" blksz: %d, blkcnt: %d, flags: 0x%x", b->blksz, b->blkcnt, b->flags);
printf(" ]\n");
}
/************************************************************/
u_int32_t
sndbuf_getflags(struct snd_dbuf *b)
{
return b->flags;
}
void
sndbuf_setflags(struct snd_dbuf *b, u_int32_t flags, int on)
{
b->flags &= ~flags;
if (on)
b->flags |= flags;
}
/**
* @brief Clear the shadow buffer by filling with samples equal to zero.
*
* @param b buffer to clear
*/
void
sndbuf_clearshadow(struct snd_dbuf *b)
{
KASSERT(b != NULL, ("b is a null pointer"));
KASSERT(b->sl >= 0, ("illegal shadow length"));
if ((b->shadbuf != NULL) && (b->sl > 0))
memset(b->shadbuf, sndbuf_zerodata(b->fmt), b->sl);
}
#ifdef OSSV4_EXPERIMENT
/**
* @brief Return peak value from samples in buffer ready area.
*
* Peak ranges from 0-32767. If channel is monaural, most significant 16
* bits will be zero. For now, only expects to work with 1-2 channel
* buffers.
*
* @note Currently only operates with linear PCM formats.
*
* @param b buffer to analyze
* @param lpeak pointer to store left peak value
* @param rpeak pointer to store right peak value
*/
void
sndbuf_getpeaks(struct snd_dbuf *b, int *lp, int *rp)
{
u_int32_t lpeak, rpeak;
lpeak = 0;
rpeak = 0;
/**
* @todo fill this in later
*/
}
#endif