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[ALSA] hda - Fix DMA position inaccuracy

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Many HD-audio controllers seem inaccurate about the IRQ timing of
PCM period updates.  This has caused problems on audio quality; e.g.
JACK doesn't work with two periods.

This patch fixes the problem by checking the current DMA position
at IRQ handler and delays the period-update via a workq if it's
inaccurate.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Takashi Iwai 2008-05-16 12:34:47 +02:00 committed by Jaroslav Kysela
parent 02330fbaad
commit 9ad593f6d3
1 changed files with 106 additions and 18 deletions
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124
sound/pci/hda/hda_intel.c
View file

@ -285,6 +285,7 @@ struct azx_dev {
u32 *posbuf; /* position buffer pointer */
unsigned int bufsize; /* size of the play buffer in bytes */
unsigned int period_bytes; /* size of the period in bytes */
unsigned int frags; /* number for period in the play buffer */
unsigned int fifo_size; /* FIFO size */
@ -301,11 +302,10 @@ struct azx_dev {
*/
unsigned char stream_tag; /* assigned stream */
unsigned char index; /* stream index */
/* for sanity check of position buffer */
unsigned int period_intr;
unsigned int opened :1;
unsigned int running :1;
unsigned int irq_pending: 1;
};
/* CORB/RIRB */
@ -369,6 +369,9 @@ struct azx {
/* for debugging */
unsigned int last_cmd; /* last issued command (to sync) */
/* for pending irqs */
struct work_struct irq_pending_work;
};
/* driver types */
@ -908,6 +911,8 @@ static void azx_init_pci(struct azx *chip)
}
static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev);
/*
* interrupt handler
*/
@ -930,11 +935,18 @@ static irqreturn_t azx_interrupt(int irq, void *dev_id)
azx_dev = &chip->azx_dev[i];
if (status & azx_dev->sd_int_sta_mask) {
azx_sd_writeb(azx_dev, SD_STS, SD_INT_MASK);
if (azx_dev->substream && azx_dev->running) {
azx_dev->period_intr++;
if (!azx_dev->substream || !azx_dev->running)
continue;
/* check whether this IRQ is really acceptable */
if (azx_position_ok(chip, azx_dev)) {
azx_dev->irq_pending = 0;
spin_unlock(&chip->reg_lock);
snd_pcm_period_elapsed(azx_dev->substream);
spin_lock(&chip->reg_lock);
} else {
/* bogus IRQ, process it later */
azx_dev->irq_pending = 1;
schedule_work(&chip->irq_pending_work);
}
}
}
@ -973,6 +985,7 @@ static int azx_setup_periods(struct snd_pcm_substream *substream,
azx_sd_writel(azx_dev, SD_BDLPU, 0);
period_bytes = snd_pcm_lib_period_bytes(substream);
azx_dev->period_bytes = period_bytes;
periods = azx_dev->bufsize / period_bytes;
/* program the initial BDL entries */
@ -1421,27 +1434,16 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
return 0;
}
static snd_pcm_uframes_t azx_pcm_pointer(struct snd_pcm_substream *substream)
static unsigned int azx_get_position(struct azx *chip,
struct azx_dev *azx_dev)
{
struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
struct azx *chip = apcm->chip;
struct azx_dev *azx_dev = get_azx_dev(substream);
unsigned int pos;
if (chip->position_fix == POS_FIX_POSBUF ||
chip->position_fix == POS_FIX_AUTO) {
/* use the position buffer */
pos = le32_to_cpu(*azx_dev->posbuf);
if (chip->position_fix == POS_FIX_AUTO &&
azx_dev->period_intr == 1 && !pos) {
printk(KERN_WARNING
"hda-intel: Invalid position buffer, "
"using LPIB read method instead.\n");
chip->position_fix = POS_FIX_NONE;
goto read_lpib;
}
} else {
read_lpib:
/* read LPIB */
pos = azx_sd_readl(azx_dev, SD_LPIB);
if (chip->position_fix == POS_FIX_FIFO)
@ -1449,7 +1451,90 @@ static snd_pcm_uframes_t azx_pcm_pointer(struct snd_pcm_substream *substream)
}
if (pos >= azx_dev->bufsize)
pos = 0;
return bytes_to_frames(substream->runtime, pos);
return pos;
}
static snd_pcm_uframes_t azx_pcm_pointer(struct snd_pcm_substream *substream)
{
struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
struct azx *chip = apcm->chip;
struct azx_dev *azx_dev = get_azx_dev(substream);
return bytes_to_frames(substream->runtime,
azx_get_position(chip, azx_dev));
}
/*
* Check whether the current DMA position is acceptable for updating
* periods. Returns non-zero if it's OK.
*
* Many HD-audio controllers appear pretty inaccurate about
* the update-IRQ timing. The IRQ is issued before actually the
* data is processed. So, we need to process it afterwords in a
* workqueue.
*/
static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
{
unsigned int pos;
pos = azx_get_position(chip, azx_dev);
if (chip->position_fix == POS_FIX_AUTO) {
if (!pos) {
printk(KERN_WARNING
"hda-intel: Invalid position buffer, "
"using LPIB read method instead.\n");
chip->position_fix = POS_FIX_NONE;
pos = azx_get_position(chip, azx_dev);
} else
chip->position_fix = POS_FIX_POSBUF;
}
if (pos % azx_dev->period_bytes > azx_dev->period_bytes / 2)
return 0; /* NG - it's below the period boundary */
return 1; /* OK, it's fine */
}
/*
* The work for pending PCM period updates.
*/
static void azx_irq_pending_work(struct work_struct *work)
{
struct azx *chip = container_of(work, struct azx, irq_pending_work);
int i, pending;
for (;;) {
pending = 0;
spin_lock_irq(&chip->reg_lock);
for (i = 0; i < chip->num_streams; i++) {
struct azx_dev *azx_dev = &chip->azx_dev[i];
if (!azx_dev->irq_pending ||
!azx_dev->substream ||
!azx_dev->running)
continue;
if (azx_position_ok(chip, azx_dev)) {
azx_dev->irq_pending = 0;
spin_unlock(&chip->reg_lock);
snd_pcm_period_elapsed(azx_dev->substream);
spin_lock(&chip->reg_lock);
} else
pending++;
}
spin_unlock_irq(&chip->reg_lock);
if (!pending)
return;
cond_resched();
}
}
/* clear irq_pending flags and assure no on-going workq */
static void azx_clear_irq_pending(struct azx *chip)
{
int i;
spin_lock_irq(&chip->reg_lock);
for (i = 0; i < chip->num_streams; i++)
chip->azx_dev[i].irq_pending = 0;
spin_unlock_irq(&chip->reg_lock);
flush_scheduled_work();
}
static struct snd_pcm_ops azx_pcm_ops = {
@ -1676,6 +1761,7 @@ static int azx_suspend(struct pci_dev *pci, pm_message_t state)
int i;
snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
azx_clear_irq_pending(chip);
for (i = 0; i < AZX_MAX_PCMS; i++)
snd_pcm_suspend_all(chip->pcm[i]);
if (chip->initialized)
@ -1732,6 +1818,7 @@ static int azx_free(struct azx *chip)
int i;
if (chip->initialized) {
azx_clear_irq_pending(chip);
for (i = 0; i < chip->num_streams; i++)
azx_stream_stop(chip, &chip->azx_dev[i]);
azx_stop_chip(chip);
@ -1857,6 +1944,7 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
chip->irq = -1;
chip->driver_type = driver_type;
chip->msi = enable_msi;
INIT_WORK(&chip->irq_pending_work, azx_irq_pending_work);
chip->position_fix = check_position_fix(chip, position_fix[dev]);
check_probe_mask(chip, dev);