linux-stable/sound/hda/hdac_stream.c

1008 lines
27 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-only
/*
* HD-audio stream operations
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clocksource.h>
#include <sound/compress_driver.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/hdaudio.h>
#include <sound/hda_register.h>
#include "trace.h"
/*
* the hdac_stream library is intended to be used with the following
* transitions. The states are not formally defined in the code but loosely
* inspired by boolean variables. Note that the 'prepared' field is not used
* in this library but by the callers during the hw_params/prepare transitions
*
* |
* stream_init() |
* v
* +--+-------+
* | unused |
* +--+----+--+
* | ^
* stream_assign() | | stream_release()
* v |
* +--+----+--+
* | opened |
* +--+----+--+
* | ^
* stream_reset() | |
* stream_setup() | | stream_cleanup()
* v |
* +--+----+--+
* | prepared |
* +--+----+--+
* | ^
* stream_start() | | stream_stop()
* v |
* +--+----+--+
* | running |
* +----------+
*/
/**
* snd_hdac_get_stream_stripe_ctl - get stripe control value
* @bus: HD-audio core bus
* @substream: PCM substream
*/
int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus,
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
unsigned int channels = runtime->channels,
rate = runtime->rate,
bits_per_sample = runtime->sample_bits,
max_sdo_lines, value, sdo_line;
/* T_AZA_GCAP_NSDO is 1:2 bitfields in GCAP */
max_sdo_lines = snd_hdac_chip_readl(bus, GCAP) & AZX_GCAP_NSDO;
/* following is from HD audio spec */
for (sdo_line = max_sdo_lines; sdo_line > 0; sdo_line >>= 1) {
if (rate > 48000)
value = (channels * bits_per_sample *
(rate / 48000)) / sdo_line;
else
value = (channels * bits_per_sample) / sdo_line;
if (value >= bus->sdo_limit)
break;
}
/* stripe value: 0 for 1SDO, 1 for 2SDO, 2 for 4SDO lines */
return sdo_line >> 1;
}
EXPORT_SYMBOL_GPL(snd_hdac_get_stream_stripe_ctl);
/**
* snd_hdac_stream_init - initialize each stream (aka device)
* @bus: HD-audio core bus
* @azx_dev: HD-audio core stream object to initialize
* @idx: stream index number
* @direction: stream direction (SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE)
* @tag: the tag id to assign
*
* Assign the starting bdl address to each stream (device) and initialize.
*/
void snd_hdac_stream_init(struct hdac_bus *bus, struct hdac_stream *azx_dev,
int idx, int direction, int tag)
{
azx_dev->bus = bus;
/* offset: SDI0=0x80, SDI1=0xa0, ... SDO3=0x160 */
azx_dev->sd_addr = bus->remap_addr + (0x20 * idx + 0x80);
/* int mask: SDI0=0x01, SDI1=0x02, ... SDO3=0x80 */
azx_dev->sd_int_sta_mask = 1 << idx;
azx_dev->index = idx;
azx_dev->direction = direction;
azx_dev->stream_tag = tag;
snd_hdac_dsp_lock_init(azx_dev);
list_add_tail(&azx_dev->list, &bus->stream_list);
if (bus->spbcap) {
azx_dev->spib_addr = bus->spbcap + AZX_SPB_BASE +
AZX_SPB_INTERVAL * idx +
AZX_SPB_SPIB;
azx_dev->fifo_addr = bus->spbcap + AZX_SPB_BASE +
AZX_SPB_INTERVAL * idx +
AZX_SPB_MAXFIFO;
}
if (bus->drsmcap)
azx_dev->dpibr_addr = bus->drsmcap + AZX_DRSM_BASE +
AZX_DRSM_INTERVAL * idx;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_init);
/**
* snd_hdac_stream_start - start a stream
* @azx_dev: HD-audio core stream to start
*
* Start a stream, set start_wallclk and set the running flag.
*/
void snd_hdac_stream_start(struct hdac_stream *azx_dev)
{
struct hdac_bus *bus = azx_dev->bus;
int stripe_ctl;
trace_snd_hdac_stream_start(bus, azx_dev);
azx_dev->start_wallclk = snd_hdac_chip_readl(bus, WALLCLK);
/* enable SIE */
snd_hdac_chip_updatel(bus, INTCTL,
1 << azx_dev->index,
1 << azx_dev->index);
/* set stripe control */
if (azx_dev->stripe) {
if (azx_dev->substream)
stripe_ctl = snd_hdac_get_stream_stripe_ctl(bus, azx_dev->substream);
else
stripe_ctl = 0;
snd_hdac_stream_updateb(azx_dev, SD_CTL_3B, SD_CTL_STRIPE_MASK,
stripe_ctl);
}
/* set DMA start and interrupt mask */
if (bus->access_sdnctl_in_dword)
snd_hdac_stream_updatel(azx_dev, SD_CTL,
0, SD_CTL_DMA_START | SD_INT_MASK);
else
snd_hdac_stream_updateb(azx_dev, SD_CTL,
0, SD_CTL_DMA_START | SD_INT_MASK);
azx_dev->running = true;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_start);
/**
* snd_hdac_stream_clear - helper to clear stream registers and stop DMA transfers
* @azx_dev: HD-audio core stream to stop
*/
static void snd_hdac_stream_clear(struct hdac_stream *azx_dev)
{
snd_hdac_stream_updateb(azx_dev, SD_CTL,
SD_CTL_DMA_START | SD_INT_MASK, 0);
snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK); /* to be sure */
if (azx_dev->stripe)
snd_hdac_stream_updateb(azx_dev, SD_CTL_3B, SD_CTL_STRIPE_MASK, 0);
azx_dev->running = false;
}
/**
* snd_hdac_stream_stop - stop a stream
* @azx_dev: HD-audio core stream to stop
*
* Stop a stream DMA and disable stream interrupt
*/
void snd_hdac_stream_stop(struct hdac_stream *azx_dev)
{
trace_snd_hdac_stream_stop(azx_dev->bus, azx_dev);
snd_hdac_stream_clear(azx_dev);
/* disable SIE */
snd_hdac_chip_updatel(azx_dev->bus, INTCTL, 1 << azx_dev->index, 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_stop);
/**
* snd_hdac_stop_streams - stop all streams
* @bus: HD-audio core bus
*/
void snd_hdac_stop_streams(struct hdac_bus *bus)
{
struct hdac_stream *stream;
list_for_each_entry(stream, &bus->stream_list, list)
snd_hdac_stream_stop(stream);
}
EXPORT_SYMBOL_GPL(snd_hdac_stop_streams);
/**
* snd_hdac_stop_streams_and_chip - stop all streams and chip if running
* @bus: HD-audio core bus
*/
void snd_hdac_stop_streams_and_chip(struct hdac_bus *bus)
{
if (bus->chip_init) {
snd_hdac_stop_streams(bus);
snd_hdac_bus_stop_chip(bus);
}
}
EXPORT_SYMBOL_GPL(snd_hdac_stop_streams_and_chip);
/**
* snd_hdac_stream_reset - reset a stream
* @azx_dev: HD-audio core stream to reset
*/
void snd_hdac_stream_reset(struct hdac_stream *azx_dev)
{
unsigned char val;
int dma_run_state;
snd_hdac_stream_clear(azx_dev);
dma_run_state = snd_hdac_stream_readb(azx_dev, SD_CTL) & SD_CTL_DMA_START;
snd_hdac_stream_updateb(azx_dev, SD_CTL, 0, SD_CTL_STREAM_RESET);
/* wait for hardware to report that the stream entered reset */
snd_hdac_stream_readb_poll(azx_dev, SD_CTL, val, (val & SD_CTL_STREAM_RESET), 3, 300);
if (azx_dev->bus->dma_stop_delay && dma_run_state)
udelay(azx_dev->bus->dma_stop_delay);
snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_CTL_STREAM_RESET, 0);
/* wait for hardware to report that the stream is out of reset */
snd_hdac_stream_readb_poll(azx_dev, SD_CTL, val, !(val & SD_CTL_STREAM_RESET), 3, 300);
/* reset first position - may not be synced with hw at this time */
if (azx_dev->posbuf)
*azx_dev->posbuf = 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_reset);
/**
* snd_hdac_stream_setup - set up the SD for streaming
* @azx_dev: HD-audio core stream to set up
*/
int snd_hdac_stream_setup(struct hdac_stream *azx_dev)
{
struct hdac_bus *bus = azx_dev->bus;
struct snd_pcm_runtime *runtime;
unsigned int val;
if (azx_dev->substream)
runtime = azx_dev->substream->runtime;
else
runtime = NULL;
/* make sure the run bit is zero for SD */
snd_hdac_stream_clear(azx_dev);
/* program the stream_tag */
val = snd_hdac_stream_readl(azx_dev, SD_CTL);
val = (val & ~SD_CTL_STREAM_TAG_MASK) |
(azx_dev->stream_tag << SD_CTL_STREAM_TAG_SHIFT);
if (!bus->snoop)
val |= SD_CTL_TRAFFIC_PRIO;
snd_hdac_stream_writel(azx_dev, SD_CTL, val);
/* program the length of samples in cyclic buffer */
snd_hdac_stream_writel(azx_dev, SD_CBL, azx_dev->bufsize);
/* program the stream format */
/* this value needs to be the same as the one programmed */
snd_hdac_stream_writew(azx_dev, SD_FORMAT, azx_dev->format_val);
/* program the stream LVI (last valid index) of the BDL */
snd_hdac_stream_writew(azx_dev, SD_LVI, azx_dev->frags - 1);
/* program the BDL address */
/* lower BDL address */
snd_hdac_stream_writel(azx_dev, SD_BDLPL, (u32)azx_dev->bdl.addr);
/* upper BDL address */
snd_hdac_stream_writel(azx_dev, SD_BDLPU,
upper_32_bits(azx_dev->bdl.addr));
/* enable the position buffer */
if (bus->use_posbuf && bus->posbuf.addr) {
if (!(snd_hdac_chip_readl(bus, DPLBASE) & AZX_DPLBASE_ENABLE))
snd_hdac_chip_writel(bus, DPLBASE,
(u32)bus->posbuf.addr | AZX_DPLBASE_ENABLE);
}
/* set the interrupt enable bits in the descriptor control register */
snd_hdac_stream_updatel(azx_dev, SD_CTL, 0, SD_INT_MASK);
azx_dev->fifo_size = snd_hdac_stream_readw(azx_dev, SD_FIFOSIZE) + 1;
/* when LPIB delay correction gives a small negative value,
* we ignore it; currently set the threshold statically to
* 64 frames
*/
if (runtime && runtime->period_size > 64)
azx_dev->delay_negative_threshold =
-frames_to_bytes(runtime, 64);
else
azx_dev->delay_negative_threshold = 0;
/* wallclk has 24Mhz clock source */
if (runtime)
azx_dev->period_wallclk = (((runtime->period_size * 24000) /
runtime->rate) * 1000);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_setup);
/**
* snd_hdac_stream_cleanup - cleanup a stream
* @azx_dev: HD-audio core stream to clean up
*/
void snd_hdac_stream_cleanup(struct hdac_stream *azx_dev)
{
snd_hdac_stream_writel(azx_dev, SD_BDLPL, 0);
snd_hdac_stream_writel(azx_dev, SD_BDLPU, 0);
snd_hdac_stream_writel(azx_dev, SD_CTL, 0);
azx_dev->bufsize = 0;
azx_dev->period_bytes = 0;
azx_dev->format_val = 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_cleanup);
/**
* snd_hdac_stream_assign - assign a stream for the PCM
* @bus: HD-audio core bus
* @substream: PCM substream to assign
*
* Look for an unused stream for the given PCM substream, assign it
* and return the stream object. If no stream is free, returns NULL.
* The function tries to keep using the same stream object when it's used
* beforehand. Also, when bus->reverse_assign flag is set, the last free
* or matching entry is returned. This is needed for some strange codecs.
*/
struct hdac_stream *snd_hdac_stream_assign(struct hdac_bus *bus,
struct snd_pcm_substream *substream)
{
struct hdac_stream *azx_dev;
struct hdac_stream *res = NULL;
/* make a non-zero unique key for the substream */
int key = (substream->pcm->device << 16) | (substream->number << 2) |
(substream->stream + 1);
spin_lock_irq(&bus->reg_lock);
list_for_each_entry(azx_dev, &bus->stream_list, list) {
if (azx_dev->direction != substream->stream)
continue;
if (azx_dev->opened)
continue;
if (azx_dev->assigned_key == key) {
res = azx_dev;
break;
}
if (!res || bus->reverse_assign)
res = azx_dev;
}
if (res) {
res->opened = 1;
res->running = 0;
res->assigned_key = key;
res->substream = substream;
}
spin_unlock_irq(&bus->reg_lock);
return res;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_assign);
/**
* snd_hdac_stream_release_locked - release the assigned stream
* @azx_dev: HD-audio core stream to release
*
* Release the stream that has been assigned by snd_hdac_stream_assign().
* The bus->reg_lock needs to be taken at a higher level
*/
void snd_hdac_stream_release_locked(struct hdac_stream *azx_dev)
{
azx_dev->opened = 0;
azx_dev->running = 0;
azx_dev->substream = NULL;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_release_locked);
/**
* snd_hdac_stream_release - release the assigned stream
* @azx_dev: HD-audio core stream to release
*
* Release the stream that has been assigned by snd_hdac_stream_assign().
*/
void snd_hdac_stream_release(struct hdac_stream *azx_dev)
{
struct hdac_bus *bus = azx_dev->bus;
spin_lock_irq(&bus->reg_lock);
snd_hdac_stream_release_locked(azx_dev);
spin_unlock_irq(&bus->reg_lock);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_release);
/**
* snd_hdac_get_stream - return hdac_stream based on stream_tag and
* direction
*
* @bus: HD-audio core bus
* @dir: direction for the stream to be found
* @stream_tag: stream tag for stream to be found
*/
struct hdac_stream *snd_hdac_get_stream(struct hdac_bus *bus,
int dir, int stream_tag)
{
struct hdac_stream *s;
list_for_each_entry(s, &bus->stream_list, list) {
if (s->direction == dir && s->stream_tag == stream_tag)
return s;
}
return NULL;
}
EXPORT_SYMBOL_GPL(snd_hdac_get_stream);
/*
* set up a BDL entry
*/
static int setup_bdle(struct hdac_bus *bus,
struct snd_dma_buffer *dmab,
struct hdac_stream *azx_dev, __le32 **bdlp,
int ofs, int size, int with_ioc)
{
__le32 *bdl = *bdlp;
while (size > 0) {
dma_addr_t addr;
int chunk;
if (azx_dev->frags >= AZX_MAX_BDL_ENTRIES)
return -EINVAL;
addr = snd_sgbuf_get_addr(dmab, ofs);
/* program the address field of the BDL entry */
bdl[0] = cpu_to_le32((u32)addr);
bdl[1] = cpu_to_le32(upper_32_bits(addr));
/* program the size field of the BDL entry */
chunk = snd_sgbuf_get_chunk_size(dmab, ofs, size);
/* one BDLE cannot cross 4K boundary on CTHDA chips */
if (bus->align_bdle_4k) {
u32 remain = 0x1000 - (ofs & 0xfff);
if (chunk > remain)
chunk = remain;
}
bdl[2] = cpu_to_le32(chunk);
/* program the IOC to enable interrupt
* only when the whole fragment is processed
*/
size -= chunk;
bdl[3] = (size || !with_ioc) ? 0 : cpu_to_le32(0x01);
bdl += 4;
azx_dev->frags++;
ofs += chunk;
}
*bdlp = bdl;
return ofs;
}
/**
* snd_hdac_stream_setup_periods - set up BDL entries
* @azx_dev: HD-audio core stream to set up
*
* Set up the buffer descriptor table of the given stream based on the
* period and buffer sizes of the assigned PCM substream.
*/
int snd_hdac_stream_setup_periods(struct hdac_stream *azx_dev)
{
struct hdac_bus *bus = azx_dev->bus;
struct snd_pcm_substream *substream = azx_dev->substream;
struct snd_compr_stream *cstream = azx_dev->cstream;
struct snd_pcm_runtime *runtime = NULL;
struct snd_dma_buffer *dmab;
__le32 *bdl;
int i, ofs, periods, period_bytes;
int pos_adj, pos_align;
if (substream) {
runtime = substream->runtime;
dmab = snd_pcm_get_dma_buf(substream);
} else if (cstream) {
dmab = snd_pcm_get_dma_buf(cstream);
} else {
WARN(1, "No substream or cstream assigned\n");
return -EINVAL;
}
/* reset BDL address */
snd_hdac_stream_writel(azx_dev, SD_BDLPL, 0);
snd_hdac_stream_writel(azx_dev, SD_BDLPU, 0);
period_bytes = azx_dev->period_bytes;
periods = azx_dev->bufsize / period_bytes;
/* program the initial BDL entries */
bdl = (__le32 *)azx_dev->bdl.area;
ofs = 0;
azx_dev->frags = 0;
pos_adj = bus->bdl_pos_adj;
if (runtime && !azx_dev->no_period_wakeup && pos_adj > 0) {
pos_align = pos_adj;
pos_adj = DIV_ROUND_UP(pos_adj * runtime->rate, 48000);
if (!pos_adj)
pos_adj = pos_align;
else
pos_adj = roundup(pos_adj, pos_align);
pos_adj = frames_to_bytes(runtime, pos_adj);
if (pos_adj >= period_bytes) {
dev_warn(bus->dev, "Too big adjustment %d\n",
pos_adj);
pos_adj = 0;
} else {
ofs = setup_bdle(bus, dmab, azx_dev,
&bdl, ofs, pos_adj, true);
if (ofs < 0)
goto error;
}
} else
pos_adj = 0;
for (i = 0; i < periods; i++) {
if (i == periods - 1 && pos_adj)
ofs = setup_bdle(bus, dmab, azx_dev,
&bdl, ofs, period_bytes - pos_adj, 0);
else
ofs = setup_bdle(bus, dmab, azx_dev,
&bdl, ofs, period_bytes,
!azx_dev->no_period_wakeup);
if (ofs < 0)
goto error;
}
return 0;
error:
dev_err(bus->dev, "Too many BDL entries: buffer=%d, period=%d\n",
azx_dev->bufsize, period_bytes);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_setup_periods);
/**
* snd_hdac_stream_set_params - set stream parameters
* @azx_dev: HD-audio core stream for which parameters are to be set
* @format_val: format value parameter
*
* Setup the HD-audio core stream parameters from substream of the stream
* and passed format value
*/
int snd_hdac_stream_set_params(struct hdac_stream *azx_dev,
unsigned int format_val)
{
struct snd_pcm_substream *substream = azx_dev->substream;
struct snd_compr_stream *cstream = azx_dev->cstream;
unsigned int bufsize, period_bytes;
unsigned int no_period_wakeup;
int err;
if (substream) {
bufsize = snd_pcm_lib_buffer_bytes(substream);
period_bytes = snd_pcm_lib_period_bytes(substream);
no_period_wakeup = substream->runtime->no_period_wakeup;
} else if (cstream) {
bufsize = cstream->runtime->buffer_size;
period_bytes = cstream->runtime->fragment_size;
no_period_wakeup = 0;
} else {
return -EINVAL;
}
if (bufsize != azx_dev->bufsize ||
period_bytes != azx_dev->period_bytes ||
format_val != azx_dev->format_val ||
no_period_wakeup != azx_dev->no_period_wakeup) {
azx_dev->bufsize = bufsize;
azx_dev->period_bytes = period_bytes;
azx_dev->format_val = format_val;
azx_dev->no_period_wakeup = no_period_wakeup;
err = snd_hdac_stream_setup_periods(azx_dev);
if (err < 0)
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_set_params);
static u64 azx_cc_read(const struct cyclecounter *cc)
{
struct hdac_stream *azx_dev = container_of(cc, struct hdac_stream, cc);
return snd_hdac_chip_readl(azx_dev->bus, WALLCLK);
}
static void azx_timecounter_init(struct hdac_stream *azx_dev,
bool force, u64 last)
{
struct timecounter *tc = &azx_dev->tc;
struct cyclecounter *cc = &azx_dev->cc;
u64 nsec;
cc->read = azx_cc_read;
cc->mask = CLOCKSOURCE_MASK(32);
/*
ALSA: hda: Make proper use of timecounter HDA uses a timecounter to read a hardware clock running at 24 MHz. The conversion factor is set with a mult value of 125 and a shift value of 0, which is not converting the hardware clock to nanoseconds, it is converting to 1/3 nanoseconds because the conversion factor from 24Mhz to nanoseconds is 125/3. The usage sites divide the "nanoseconds" value returned by timecounter_read() by 3 to get a real nanoseconds value. There is a lengthy comment in azx_timecounter_init() explaining this choice. That comment makes blatantly wrong assumptions about how timecounters work and what can overflow. The comment says: * Applying the 1/3 factor as part of the multiplication * requires at least 20 bits for a decent precision, however * overflows occur after about 4 hours or less, not a option. timecounters operate on time deltas between two readouts of a clock and use the mult/shift pair to calculate a precise nanoseconds value: delta_nsec = (delta_clock * mult) >> shift; The fractional part is also taken into account and preserved to prevent accumulated rounding errors. For details see cyclecounter_cyc2ns(). The mult/shift pair has to be chosen so that the multiplication of the maximum expected delta value does not result in a 64bit overflow. As the counter wraps around on 32bit, the maximum observable delta between two reads is (1 << 32) - 1 which is about 178.9 seconds. That in turn means the maximum multiplication factor which fits into an u32 will not cause a 64bit overflow ever because it's guaranteed that: ((1 << 32) - 1) ^ 2 < (1 << 64) The resulting correct multiplication factor is 2796202667 and the shift value is 26, i.e. 26 bit precision. The overflow of the multiplication would happen exactly at a clock readout delta of 6597069765 which is way after the wrap around of the hardware clock at around 274.8 seconds which is off from the claimed 4 hours by more than an order of magnitude. If the counter ever wraps around the last read value then the calculation is off by the number of wrap arounds times 178.9 seconds because the overflow cannot be observed. Use clocks_calc_mult_shift(), which calculates the most accurate mult/shift pair based on the given clock frequency, and remove the bogus comment along with the divisions at the readout sites. Fixes: 5d890f591d15 ("ALSA: hda: support for wallclock timestamps") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/871r35kwji.ffs@tglx Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-24 22:40:01 +00:00
* Calculate the optimal mult/shift values. The counter wraps
* around after ~178.9 seconds.
*/
ALSA: hda: Make proper use of timecounter HDA uses a timecounter to read a hardware clock running at 24 MHz. The conversion factor is set with a mult value of 125 and a shift value of 0, which is not converting the hardware clock to nanoseconds, it is converting to 1/3 nanoseconds because the conversion factor from 24Mhz to nanoseconds is 125/3. The usage sites divide the "nanoseconds" value returned by timecounter_read() by 3 to get a real nanoseconds value. There is a lengthy comment in azx_timecounter_init() explaining this choice. That comment makes blatantly wrong assumptions about how timecounters work and what can overflow. The comment says: * Applying the 1/3 factor as part of the multiplication * requires at least 20 bits for a decent precision, however * overflows occur after about 4 hours or less, not a option. timecounters operate on time deltas between two readouts of a clock and use the mult/shift pair to calculate a precise nanoseconds value: delta_nsec = (delta_clock * mult) >> shift; The fractional part is also taken into account and preserved to prevent accumulated rounding errors. For details see cyclecounter_cyc2ns(). The mult/shift pair has to be chosen so that the multiplication of the maximum expected delta value does not result in a 64bit overflow. As the counter wraps around on 32bit, the maximum observable delta between two reads is (1 << 32) - 1 which is about 178.9 seconds. That in turn means the maximum multiplication factor which fits into an u32 will not cause a 64bit overflow ever because it's guaranteed that: ((1 << 32) - 1) ^ 2 < (1 << 64) The resulting correct multiplication factor is 2796202667 and the shift value is 26, i.e. 26 bit precision. The overflow of the multiplication would happen exactly at a clock readout delta of 6597069765 which is way after the wrap around of the hardware clock at around 274.8 seconds which is off from the claimed 4 hours by more than an order of magnitude. If the counter ever wraps around the last read value then the calculation is off by the number of wrap arounds times 178.9 seconds because the overflow cannot be observed. Use clocks_calc_mult_shift(), which calculates the most accurate mult/shift pair based on the given clock frequency, and remove the bogus comment along with the divisions at the readout sites. Fixes: 5d890f591d15 ("ALSA: hda: support for wallclock timestamps") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/871r35kwji.ffs@tglx Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-24 22:40:01 +00:00
clocks_calc_mult_shift(&cc->mult, &cc->shift, 24000000,
NSEC_PER_SEC, 178);
nsec = 0; /* audio time is elapsed time since trigger */
timecounter_init(tc, cc, nsec);
if (force) {
/*
* force timecounter to use predefined value,
* used for synchronized starts
*/
tc->cycle_last = last;
}
}
/**
* snd_hdac_stream_timecounter_init - initialize time counter
* @azx_dev: HD-audio core stream (master stream)
* @streams: bit flags of streams to set up
*
* Initializes the time counter of streams marked by the bit flags (each
* bit corresponds to the stream index).
* The trigger timestamp of PCM substream assigned to the given stream is
* updated accordingly, too.
*/
void snd_hdac_stream_timecounter_init(struct hdac_stream *azx_dev,
unsigned int streams)
{
struct hdac_bus *bus = azx_dev->bus;
struct snd_pcm_runtime *runtime = azx_dev->substream->runtime;
struct hdac_stream *s;
bool inited = false;
u64 cycle_last = 0;
int i = 0;
list_for_each_entry(s, &bus->stream_list, list) {
if (streams & (1 << i)) {
azx_timecounter_init(s, inited, cycle_last);
if (!inited) {
inited = true;
cycle_last = s->tc.cycle_last;
}
}
i++;
}
snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
runtime->trigger_tstamp_latched = true;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_timecounter_init);
/**
* snd_hdac_stream_sync_trigger - turn on/off stream sync register
* @azx_dev: HD-audio core stream (master stream)
* @set: true = set, false = clear
* @streams: bit flags of streams to sync
* @reg: the stream sync register address
*/
void snd_hdac_stream_sync_trigger(struct hdac_stream *azx_dev, bool set,
unsigned int streams, unsigned int reg)
{
struct hdac_bus *bus = azx_dev->bus;
unsigned int val;
if (!reg)
reg = AZX_REG_SSYNC;
val = _snd_hdac_chip_readl(bus, reg);
if (set)
val |= streams;
else
val &= ~streams;
_snd_hdac_chip_writel(bus, reg, val);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_sync_trigger);
/**
* snd_hdac_stream_sync - sync with start/stop trigger operation
* @azx_dev: HD-audio core stream (master stream)
* @start: true = start, false = stop
* @streams: bit flags of streams to sync
*
* For @start = true, wait until all FIFOs get ready.
* For @start = false, wait until all RUN bits are cleared.
*/
void snd_hdac_stream_sync(struct hdac_stream *azx_dev, bool start,
unsigned int streams)
{
struct hdac_bus *bus = azx_dev->bus;
int i, nwait, timeout;
struct hdac_stream *s;
for (timeout = 5000; timeout; timeout--) {
nwait = 0;
i = 0;
list_for_each_entry(s, &bus->stream_list, list) {
ALSA: hda: Reset stream if DMA RUN bit not cleared Tegra HDA has FIFO size which can hold upto 10 audio frames to support DVFS. When HDA DMA RUN bit is set to 0 to stop the stream, the DMA RUN bit will be cleared to 0 only after transferring all the remaining audio frames queued up in the fifo. This is not in sync with spec which states the controller will stop transmitting(output) in the beginning of the next frame for the relevant stream. The above behavior with Tegra HDA was resulting in machine check error during the system suspend flow with active audio playback with below kernel error logs. [ 33.524583] mc-err: [mcerr] (hda) csr_hdar: EMEM address decode error [ 33.531088] mc-err: [mcerr] status = 0x20000015; addr = 0x00000000 [ 33.537431] mc-err: [mcerr] secure: no, access-type: read, SMMU fault: none This was due to the fifo has more than one audio frame when the DMA RUN bit is set to 0 during system suspend flow and the timeout handling in snd_hdac_stream_sync() was not designed to handle this scenario. So the DMA will continue running even after timeout hit until all remaining audio frames in the fifo are transferred, but the suspend flow will try to reset the controller and turn off the hda clocks without the knowledge of the DMA is still running and could result in mc-err. The above issue can be resolved by doing stream reset with the help of snd_hdac_stream_reset() which would ensure the DMA RUN bit is cleared if the timeout was hit in snd_hdac_stream_sync(). Signed-off-by: Mohan Kumar <mkumard@nvidia.com> Link: https://lore.kernel.org/r/20200128051508.26064-1-mkumard@nvidia.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-28 05:15:08 +00:00
if (!(streams & (1 << i++)))
continue;
if (start) {
/* check FIFO gets ready */
if (!(snd_hdac_stream_readb(s, SD_STS) &
SD_STS_FIFO_READY))
nwait++;
} else {
/* check RUN bit is cleared */
if (snd_hdac_stream_readb(s, SD_CTL) &
SD_CTL_DMA_START) {
nwait++;
/*
* Perform stream reset if DMA RUN
* bit not cleared within given timeout
*/
if (timeout == 1)
snd_hdac_stream_reset(s);
}
}
}
if (!nwait)
break;
cpu_relax();
}
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_sync);
/**
* snd_hdac_stream_spbcap_enable - enable SPIB for a stream
* @bus: HD-audio core bus
* @enable: flag to enable/disable SPIB
* @index: stream index for which SPIB need to be enabled
*/
void snd_hdac_stream_spbcap_enable(struct hdac_bus *bus,
bool enable, int index)
{
u32 mask = 0;
if (!bus->spbcap) {
dev_err(bus->dev, "Address of SPB capability is NULL\n");
return;
}
mask |= (1 << index);
if (enable)
snd_hdac_updatel(bus->spbcap, AZX_REG_SPB_SPBFCCTL, mask, mask);
else
snd_hdac_updatel(bus->spbcap, AZX_REG_SPB_SPBFCCTL, mask, 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_spbcap_enable);
/**
* snd_hdac_stream_set_spib - sets the spib value of a stream
* @bus: HD-audio core bus
* @azx_dev: hdac_stream
* @value: spib value to set
*/
int snd_hdac_stream_set_spib(struct hdac_bus *bus,
struct hdac_stream *azx_dev, u32 value)
{
if (!bus->spbcap) {
dev_err(bus->dev, "Address of SPB capability is NULL\n");
return -EINVAL;
}
writel(value, azx_dev->spib_addr);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_set_spib);
/**
* snd_hdac_stream_get_spbmaxfifo - gets the spib value of a stream
* @bus: HD-audio core bus
* @azx_dev: hdac_stream
*
* Return maxfifo for the stream
*/
int snd_hdac_stream_get_spbmaxfifo(struct hdac_bus *bus,
struct hdac_stream *azx_dev)
{
if (!bus->spbcap) {
dev_err(bus->dev, "Address of SPB capability is NULL\n");
return -EINVAL;
}
return readl(azx_dev->fifo_addr);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_get_spbmaxfifo);
/**
* snd_hdac_stream_drsm_enable - enable DMA resume for a stream
* @bus: HD-audio core bus
* @enable: flag to enable/disable DRSM
* @index: stream index for which DRSM need to be enabled
*/
void snd_hdac_stream_drsm_enable(struct hdac_bus *bus,
bool enable, int index)
{
u32 mask = 0;
if (!bus->drsmcap) {
dev_err(bus->dev, "Address of DRSM capability is NULL\n");
return;
}
mask |= (1 << index);
if (enable)
snd_hdac_updatel(bus->drsmcap, AZX_REG_DRSM_CTL, mask, mask);
else
snd_hdac_updatel(bus->drsmcap, AZX_REG_DRSM_CTL, mask, 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_drsm_enable);
/*
* snd_hdac_stream_wait_drsm - wait for HW to clear RSM for a stream
* @azx_dev: HD-audio core stream to await RSM for
*
* Returns 0 on success and -ETIMEDOUT upon a timeout.
*/
int snd_hdac_stream_wait_drsm(struct hdac_stream *azx_dev)
{
struct hdac_bus *bus = azx_dev->bus;
u32 mask, reg;
int ret;
mask = 1 << azx_dev->index;
ret = read_poll_timeout(snd_hdac_reg_readl, reg, !(reg & mask), 250, 2000, false, bus,
bus->drsmcap + AZX_REG_DRSM_CTL);
if (ret)
dev_dbg(bus->dev, "polling RSM 0x%08x failed: %d\n", mask, ret);
return ret;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_wait_drsm);
/**
* snd_hdac_stream_set_dpibr - sets the dpibr value of a stream
* @bus: HD-audio core bus
* @azx_dev: hdac_stream
* @value: dpib value to set
*/
int snd_hdac_stream_set_dpibr(struct hdac_bus *bus,
struct hdac_stream *azx_dev, u32 value)
{
if (!bus->drsmcap) {
dev_err(bus->dev, "Address of DRSM capability is NULL\n");
return -EINVAL;
}
writel(value, azx_dev->dpibr_addr);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_set_dpibr);
/**
* snd_hdac_stream_set_lpib - sets the lpib value of a stream
* @azx_dev: hdac_stream
* @value: lpib value to set
*/
int snd_hdac_stream_set_lpib(struct hdac_stream *azx_dev, u32 value)
{
snd_hdac_stream_writel(azx_dev, SD_LPIB, value);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_set_lpib);
#ifdef CONFIG_SND_HDA_DSP_LOADER
/**
* snd_hdac_dsp_prepare - prepare for DSP loading
* @azx_dev: HD-audio core stream used for DSP loading
* @format: HD-audio stream format
* @byte_size: data chunk byte size
* @bufp: allocated buffer
*
* Allocate the buffer for the given size and set up the given stream for
* DSP loading. Returns the stream tag (>= 0), or a negative error code.
*/
int snd_hdac_dsp_prepare(struct hdac_stream *azx_dev, unsigned int format,
unsigned int byte_size, struct snd_dma_buffer *bufp)
{
struct hdac_bus *bus = azx_dev->bus;
__le32 *bdl;
int err;
snd_hdac_dsp_lock(azx_dev);
spin_lock_irq(&bus->reg_lock);
if (azx_dev->running || azx_dev->locked) {
spin_unlock_irq(&bus->reg_lock);
err = -EBUSY;
goto unlock;
}
azx_dev->locked = true;
spin_unlock_irq(&bus->reg_lock);
err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, bus->dev,
byte_size, bufp);
if (err < 0)
goto err_alloc;
azx_dev->substream = NULL;
azx_dev->bufsize = byte_size;
azx_dev->period_bytes = byte_size;
azx_dev->format_val = format;
snd_hdac_stream_reset(azx_dev);
/* reset BDL address */
snd_hdac_stream_writel(azx_dev, SD_BDLPL, 0);
snd_hdac_stream_writel(azx_dev, SD_BDLPU, 0);
azx_dev->frags = 0;
bdl = (__le32 *)azx_dev->bdl.area;
err = setup_bdle(bus, bufp, azx_dev, &bdl, 0, byte_size, 0);
if (err < 0)
goto error;
snd_hdac_stream_setup(azx_dev);
snd_hdac_dsp_unlock(azx_dev);
return azx_dev->stream_tag;
error:
snd_dma_free_pages(bufp);
err_alloc:
spin_lock_irq(&bus->reg_lock);
azx_dev->locked = false;
spin_unlock_irq(&bus->reg_lock);
unlock:
snd_hdac_dsp_unlock(azx_dev);
return err;
}
EXPORT_SYMBOL_GPL(snd_hdac_dsp_prepare);
/**
* snd_hdac_dsp_trigger - start / stop DSP loading
* @azx_dev: HD-audio core stream used for DSP loading
* @start: trigger start or stop
*/
void snd_hdac_dsp_trigger(struct hdac_stream *azx_dev, bool start)
{
if (start)
snd_hdac_stream_start(azx_dev);
else
snd_hdac_stream_stop(azx_dev);
}
EXPORT_SYMBOL_GPL(snd_hdac_dsp_trigger);
/**
* snd_hdac_dsp_cleanup - clean up the stream from DSP loading to normal
* @azx_dev: HD-audio core stream used for DSP loading
* @dmab: buffer used by DSP loading
*/
void snd_hdac_dsp_cleanup(struct hdac_stream *azx_dev,
struct snd_dma_buffer *dmab)
{
struct hdac_bus *bus = azx_dev->bus;
if (!dmab->area || !azx_dev->locked)
return;
snd_hdac_dsp_lock(azx_dev);
/* reset BDL address */
snd_hdac_stream_writel(azx_dev, SD_BDLPL, 0);
snd_hdac_stream_writel(azx_dev, SD_BDLPU, 0);
snd_hdac_stream_writel(azx_dev, SD_CTL, 0);
azx_dev->bufsize = 0;
azx_dev->period_bytes = 0;
azx_dev->format_val = 0;
snd_dma_free_pages(dmab);
dmab->area = NULL;
spin_lock_irq(&bus->reg_lock);
azx_dev->locked = false;
spin_unlock_irq(&bus->reg_lock);
snd_hdac_dsp_unlock(azx_dev);
}
EXPORT_SYMBOL_GPL(snd_hdac_dsp_cleanup);
#endif /* CONFIG_SND_HDA_DSP_LOADER */