- 根目录:
- sound
- drivers
- pcm-indirect2.c
/*
* Helper functions for indirect PCM data transfer to a simple FIFO in
* hardware (small, no possibility to read "hardware io position",
* updating position done by interrupt, ...)
*
* Copyright (c) by 2007 Joachim Foerster <JOFT@gmx.de>
*
* Based on "pcm-indirect.h" (alsa-driver-1.0.13) by
*
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
* Jaroslav Kysela <perex@suse.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* snd_printk/d() */
#include <sound/core.h>
/* struct snd_pcm_substream, struct snd_pcm_runtime, snd_pcm_uframes_t
* snd_pcm_period_elapsed() */
#include <sound/pcm.h>
#include "pcm-indirect2.h"
#ifdef SND_PCM_INDIRECT2_STAT
/* jiffies */
#include <linux/jiffies.h>
void snd_pcm_indirect2_stat(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int i;
int j;
int k;
int seconds = (rec->lastbytetime - rec->firstbytetime) / HZ;
snd_printk(KERN_DEBUG "STAT: mul_elapsed: %u, mul_elapsed_real: %d, "
"irq_occured: %d\n",
rec->mul_elapsed, rec->mul_elapsed_real, rec->irq_occured);
snd_printk(KERN_DEBUG "STAT: min_multiple: %d (irqs/period)\n",
rec->min_multiple);
snd_printk(KERN_DEBUG "STAT: firstbytetime: %lu, lastbytetime: %lu, "
"firstzerotime: %lu\n",
rec->firstbytetime, rec->lastbytetime, rec->firstzerotime);
snd_printk(KERN_DEBUG "STAT: bytes2hw: %u Bytes => (by runtime->rate) "
"length: %d s\n",
rec->bytes2hw, rec->bytes2hw / 2 / 2 / runtime->rate);
snd_printk(KERN_DEBUG "STAT: (by measurement) length: %d => "
"rate: %d Bytes/s = %d Frames/s|Hz\n",
seconds, rec->bytes2hw / seconds,
rec->bytes2hw / 2 / 2 / seconds);
snd_printk(KERN_DEBUG
"STAT: zeros2hw: %u = %d ms ~ %d * %d zero copies\n",
rec->zeros2hw, ((rec->zeros2hw / 2 / 2) * 1000) /
runtime->rate,
rec->zeros2hw / (rec->hw_buffer_size / 2),
(rec->hw_buffer_size / 2));
snd_printk(KERN_DEBUG "STAT: pointer_calls: %u, lastdifftime: %u\n",
rec->pointer_calls, rec->lastdifftime);
snd_printk(KERN_DEBUG "STAT: sw_io: %d, sw_data: %d\n", rec->sw_io,
rec->sw_data);
snd_printk(KERN_DEBUG "STAT: byte_sizes[]:\n");
k = 0;
for (j = 0; j < 8; j++) {
for (i = j * 8; i < (j + 1) * 8; i++)
if (rec->byte_sizes[i] != 0) {
snd_printk(KERN_DEBUG "%u: %u",
i, rec->byte_sizes[i]);
k++;
}
if (((k % 8) == 0) && (k != 0)) {
snd_printk(KERN_DEBUG "\n");
k = 0;
}
}
snd_printk(KERN_DEBUG "\n");
snd_printk(KERN_DEBUG "STAT: zero_sizes[]:\n");
for (j = 0; j < 8; j++) {
k = 0;
for (i = j * 8; i < (j + 1) * 8; i++)
if (rec->zero_sizes[i] != 0)
snd_printk(KERN_DEBUG "%u: %u",
i, rec->zero_sizes[i]);
else
k++;
if (!k)
snd_printk(KERN_DEBUG "\n");
}
snd_printk(KERN_DEBUG "\n");
snd_printk(KERN_DEBUG "STAT: min_adds[]:\n");
for (j = 0; j < 8; j++) {
if (rec->min_adds[j] != 0)
snd_printk(KERN_DEBUG "%u: %u", j, rec->min_adds[j]);
}
snd_printk(KERN_DEBUG "\n");
snd_printk(KERN_DEBUG "STAT: mul_adds[]:\n");
for (j = 0; j < 8; j++) {
if (rec->mul_adds[j] != 0)
snd_printk(KERN_DEBUG "%u: %u", j, rec->mul_adds[j]);
}
snd_printk(KERN_DEBUG "\n");
snd_printk(KERN_DEBUG
"STAT: zero_times_saved: %d, zero_times_notsaved: %d\n",
rec->zero_times_saved, rec->zero_times_notsaved);
/* snd_printk(KERN_DEBUG "STAT: zero_times[]\n");
i = 0;
for (j = 0; j < 3750; j++) {
if (rec->zero_times[j] != 0) {
snd_printk(KERN_DEBUG "%u: %u", j, rec->zero_times[j]);
i++;
}
if (((i % 8) == 0) && (i != 0))
snd_printk(KERN_DEBUG "\n");
}
snd_printk(KERN_DEBUG "\n"); */
return;
}
#endif
/*
* _internal_ helper function for playback/capture transfer function
*/
static void
snd_pcm_indirect2_increase_min_periods(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
int isplay, int iscopy,
unsigned int bytes)
{
if (rec->min_periods >= 0) {
if (iscopy) {
rec->sw_io += bytes;
if (rec->sw_io >= rec->sw_buffer_size)
rec->sw_io -= rec->sw_buffer_size;
} else if (isplay) {
/* If application does not write data in multiples of
* a period, move sw_data to the next correctly aligned
* position, so that sw_io can converge to it (in the
* next step).
*/
if (!rec->check_alignment) {
if (rec->bytes2hw %
snd_pcm_lib_period_bytes(substream)) {
unsigned bytes2hw_aligned =
(1 +
(rec->bytes2hw /
snd_pcm_lib_period_bytes
(substream))) *
snd_pcm_lib_period_bytes
(substream);
rec->sw_data =
bytes2hw_aligned %
rec->sw_buffer_size;
#ifdef SND_PCM_INDIRECT2_STAT
snd_printk(KERN_DEBUG
"STAT: @re-align: aligned "
"bytes2hw to next period "
"size boundary: %d "
"(instead of %d)\n",
bytes2hw_aligned,
rec->bytes2hw);
snd_printk(KERN_DEBUG
"STAT: @re-align: sw_data "
"moves to: %d\n",
rec->sw_data);
#endif
}
rec->check_alignment = 1;
}
/* We are at the end and are copying zeros into the
* fifo.
* Now, we have to make sure that sw_io is increased
* until the position of sw_data: Filling the fifo with
* the first zeros means, the last bytes were played.
*/
if (rec->sw_io != rec->sw_data) {
unsigned int diff;
if (rec->sw_data > rec->sw_io)
diff = rec->sw_data - rec->sw_io;
else
diff = (rec->sw_buffer_size -
rec->sw_io) +
rec->sw_data;
if (bytes >= diff)
rec->sw_io = rec->sw_data;
else {
rec->sw_io += bytes;
if (rec->sw_io >= rec->sw_buffer_size)
rec->sw_io -=
rec->sw_buffer_size;
}
}
}
rec->min_period_count += bytes;
if (rec->min_period_count >= (rec->hw_buffer_size / 2)) {
rec->min_periods += (rec->min_period_count /
(rec->hw_buffer_size / 2));
#ifdef SND_PCM_INDIRECT2_STAT
if ((rec->min_period_count /
(rec->hw_buffer_size / 2)) > 7)
snd_printk(KERN_DEBUG
"STAT: more than 7 (%d) min_adds "
"at once - too big to save!\n",
(rec->min_period_count /
(rec->hw_buffer_size / 2)));
else
rec->min_adds[(rec->min_period_count /
(rec->hw_buffer_size / 2))]++;
#endif
rec->min_period_count = (rec->min_period_count %
(rec->hw_buffer_size / 2));
}
} else if (isplay && iscopy)
rec->min_periods = 0;
}
/*
* helper function for playback/capture pointer callback
*/
snd_pcm_uframes_t
snd_pcm_indirect2_pointer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec)
{
#ifdef SND_PCM_INDIRECT2_STAT
rec->pointer_calls++;
#endif
return bytes_to_frames(substream->runtime, rec->sw_io);
}
/*
* _internal_ helper function for playback interrupt callback
*/
static void
snd_pcm_indirect2_playback_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t zero)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
/* runtime->control->appl_ptr: position where ALSA will write next time
* rec->appl_ptr: position where ALSA was last time
* diff: obviously ALSA wrote that much bytes into the intermediate
* buffer since we checked last time
*/
snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
if (diff) {
#ifdef SND_PCM_INDIRECT2_STAT
rec->lastdifftime = jiffies;
#endif
if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
diff += runtime->boundary;
/* number of bytes "added" by ALSA increases the number of
* bytes which are ready to "be transferred to HW"/"played"
* Then, set rec->appl_ptr to not count bytes twice next time.
*/
rec->sw_ready += (int)frames_to_bytes(runtime, diff);
rec->appl_ptr = appl_ptr;
}
if (rec->hw_ready && (rec->sw_ready <= 0)) {
unsigned int bytes;
#ifdef SND_PCM_INDIRECT2_STAT
if (rec->firstzerotime == 0) {
rec->firstzerotime = jiffies;
snd_printk(KERN_DEBUG
"STAT: @firstzerotime: mul_elapsed: %d, "
"min_period_count: %d\n",
rec->mul_elapsed, rec->min_period_count);
snd_printk(KERN_DEBUG
"STAT: @firstzerotime: sw_io: %d, "
"sw_data: %d, appl_ptr: %u\n",
rec->sw_io, rec->sw_data,
(unsigned int)appl_ptr);
}
if ((jiffies - rec->firstzerotime) < 3750) {
rec->zero_times[(jiffies - rec->firstzerotime)]++;
rec->zero_times_saved++;
} else
rec->zero_times_notsaved++;
#endif
bytes = zero(substream, rec);
#ifdef SND_PCM_INDIRECT2_STAT
rec->zeros2hw += bytes;
if (bytes < 64)
rec->zero_sizes[bytes]++;
else
snd_printk(KERN_DEBUG
"STAT: %d zero Bytes copied to hardware at "
"once - too big to save!\n",
bytes);
#endif
snd_pcm_indirect2_increase_min_periods(substream, rec, 1, 0,
bytes);
return;
}
while (rec->hw_ready && (rec->sw_ready > 0)) {
/* sw_to_end: max. number of bytes that can be read/take from
* the current position (sw_data) in _one_ step
*/
unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data;
/* bytes: number of bytes we have available (for reading) */
unsigned int bytes = rec->sw_ready;
if (sw_to_end < bytes)
bytes = sw_to_end;
if (!bytes)
break;
#ifdef SND_PCM_INDIRECT2_STAT
if (rec->firstbytetime == 0)
rec->firstbytetime = jiffies;
rec->lastbytetime = jiffies;
#endif
/* copy bytes from intermediate buffer position sw_data to the
* HW and return number of bytes actually written
* Furthermore, set hw_ready to 0, if the fifo isn't empty
* now => more could be transferred to fifo
*/
bytes = copy(substream, rec, bytes);
rec->bytes2hw += bytes;
#ifdef SND_PCM_INDIRECT2_STAT
if (bytes < 64)
rec->byte_sizes[bytes]++;
else
snd_printk(KERN_DEBUG
"STAT: %d Bytes copied to hardware at once "
"- too big to save!\n",
bytes);
#endif
/* increase sw_data by the number of actually written bytes
* (= number of taken bytes from intermediate buffer)
*/
rec->sw_data += bytes;
if (rec->sw_data == rec->sw_buffer_size)
rec->sw_data = 0;
/* now sw_data is the position where ALSA is going to write
* in the intermediate buffer next time = position we are going
* to read from next time
*/
snd_pcm_indirect2_increase_min_periods(substream, rec, 1, 1,
bytes);
/* we read bytes from intermediate buffer, so we need to say
* that the number of bytes ready for transfer are decreased
* now
*/
rec->sw_ready -= bytes;
}
return;
}
/*
* helper function for playback interrupt routine
*/
void
snd_pcm_indirect2_playback_interrupt(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t zero)
{
#ifdef SND_PCM_INDIRECT2_STAT
rec->irq_occured++;
#endif
/* hardware played some bytes, so there is room again (in fifo) */
rec->hw_ready = 1;
/* don't call ack() now, instead call transfer() function directly
* (normally called by ack() )
*/
snd_pcm_indirect2_playback_transfer(substream, rec, copy, zero);
if (rec->min_periods >= rec->min_multiple) {
#ifdef SND_PCM_INDIRECT2_STAT
if ((rec->min_periods / rec->min_multiple) > 7)
snd_printk(KERN_DEBUG
"STAT: more than 7 (%d) mul_adds - too big "
"to save!\n",
(rec->min_periods / rec->min_multiple));
else
rec->mul_adds[(rec->min_periods /
rec->min_multiple)]++;
rec->mul_elapsed_real += (rec->min_periods /
rec->min_multiple);
rec->mul_elapsed++;
#endif
rec->min_periods = (rec->min_periods % rec->min_multiple);
snd_pcm_period_elapsed(substream);
}
}
/*
* _internal_ helper function for capture interrupt callback
*/
static void
snd_pcm_indirect2_capture_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t null)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
if (diff) {
#ifdef SND_PCM_INDIRECT2_STAT
rec->lastdifftime = jiffies;
#endif
if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
diff += runtime->boundary;
rec->sw_ready -= frames_to_bytes(runtime, diff);
rec->appl_ptr = appl_ptr;
}
/* if hardware has something, but the intermediate buffer is full
* => skip contents of buffer
*/
if (rec->hw_ready && (rec->sw_ready >= (int)rec->sw_buffer_size)) {
unsigned int bytes;
#ifdef SND_PCM_INDIRECT2_STAT
if (rec->firstzerotime == 0) {
rec->firstzerotime = jiffies;
snd_printk(KERN_DEBUG "STAT: (capture) "
"@firstzerotime: mul_elapsed: %d, "
"min_period_count: %d\n",
rec->mul_elapsed, rec->min_period_count);
snd_printk(KERN_DEBUG "STAT: (capture) "
"@firstzerotime: sw_io: %d, sw_data: %d, "
"appl_ptr: %u\n",
rec->sw_io, rec->sw_data,
(unsigned int)appl_ptr);
}
if ((jiffies - rec->firstzerotime) < 3750) {
rec->zero_times[(jiffies - rec->firstzerotime)]++;
rec->zero_times_saved++;
} else
rec->zero_times_notsaved++;
#endif
bytes = null(substream, rec);
#ifdef SND_PCM_INDIRECT2_STAT
rec->zeros2hw += bytes;
if (bytes < 64)
rec->zero_sizes[bytes]++;
else
snd_printk(KERN_DEBUG
"STAT: (capture) %d zero Bytes copied to "
"hardware at once - too big to save!\n",
bytes);
#endif
snd_pcm_indirect2_increase_min_periods(substream, rec, 0, 0,
bytes);
/* report an overrun */
rec->sw_io = SNDRV_PCM_POS_XRUN;
return;
}
while (rec->hw_ready && (rec->sw_ready < (int)rec->sw_buffer_size)) {
/* sw_to_end: max. number of bytes that we can write to the
* intermediate buffer (until it's end)
*/
size_t sw_to_end = rec->sw_buffer_size - rec->sw_data;
/* bytes: max. number of bytes, which may be copied to the
* intermediate buffer without overflow (in _one_ step)
*/
size_t bytes = rec->sw_buffer_size - rec->sw_ready;
/* limit number of bytes (for transfer) by available room in
* the intermediate buffer
*/
if (sw_to_end < bytes)
bytes = sw_to_end;
if (!bytes)
break;
#ifdef SND_PCM_INDIRECT2_STAT
if (rec->firstbytetime == 0)
rec->firstbytetime = jiffies;
rec->lastbytetime = jiffies;
#endif
/* copy bytes from the intermediate buffer (position sw_data)
* to the HW at most and return number of bytes actually copied
* from HW
* Furthermore, set hw_ready to 0, if the fifo is empty now.
*/
bytes = copy(substream, rec, bytes);
rec->bytes2hw += bytes;
#ifdef SND_PCM_INDIRECT2_STAT
if (bytes < 64)
rec->byte_sizes[bytes]++;
else
snd_printk(KERN_DEBUG
"STAT: (capture) %d Bytes copied to "
"hardware at once - too big to save!\n",
bytes);
#endif
/* increase sw_data by the number of actually copied bytes from
* HW
*/
rec->sw_data += bytes;
if (rec->sw_data == rec->sw_buffer_size)
rec->sw_data = 0;
snd_pcm_indirect2_increase_min_periods(substream, rec, 0, 1,
bytes);
/* number of bytes in the intermediate buffer, which haven't
* been fetched by ALSA yet.
*/
rec->sw_ready += bytes;
}
return;
}
/*
* helper function for capture interrupt routine
*/
void
snd_pcm_indirect2_capture_interrupt(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t null)
{
#ifdef SND_PCM_INDIRECT2_STAT
rec->irq_occured++;
#endif
/* hardware recorded some bytes, so there is something to read from the
* record fifo:
*/
rec->hw_ready = 1;
/* don't call ack() now, instead call transfer() function directly
* (normally called by ack() )
*/
snd_pcm_indirect2_capture_transfer(substream, rec, copy, null);
if (rec->min_periods >= rec->min_multiple) {
#ifdef SND_PCM_INDIRECT2_STAT
if ((rec->min_periods / rec->min_multiple) > 7)
snd_printk(KERN_DEBUG
"STAT: more than 7 (%d) mul_adds - "
"too big to save!\n",
(rec->min_periods / rec->min_multiple));
else
rec->mul_adds[(rec->min_periods /
rec->min_multiple)]++;
rec->mul_elapsed_real += (rec->min_periods /
rec->min_multiple);
rec->mul_elapsed++;
#endif
rec->min_periods = (rec->min_periods % rec->min_multiple);
snd_pcm_period_elapsed(substream);
}
}