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[ALSA] intel8x0: do not use zero value from PICB register

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It seems that the zero value from the PICB (position in current buffer)
register is not reliable. Use jiffies to correct returned value
from the ring buffer pointer callback.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Jaroslav Kysela 2009-04-13 21:31:25 +02:00
parent 920e4ae31c
commit da2436a23c
1 changed files with 33 additions and 10 deletions
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43
sound/pci/intel8x0.c
View file

@ -355,6 +355,9 @@ struct ichdev {
unsigned int fragsize1;
unsigned int position;
unsigned int pos_shift;
unsigned int last_pos;
unsigned long last_pos_jiffies;
unsigned int jiffy_to_bytes;
int frags;
int lvi;
int lvi_frag;
@ -838,7 +841,10 @@ static int snd_intel8x0_pcm_trigger(struct snd_pcm_substream *substream, int cmd
ichdev->suspended = 0;
/* fallthru */
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
val = ICH_IOCE | ICH_STARTBM;
ichdev->last_pos = ichdev->position;
ichdev->last_pos_jiffies = jiffies;
break;
case SNDRV_PCM_TRIGGER_SUSPEND:
ichdev->suspended = 1;
@ -849,9 +855,6 @@ static int snd_intel8x0_pcm_trigger(struct snd_pcm_substream *substream, int cmd
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
val = ICH_IOCE;
break;
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
val = ICH_IOCE | ICH_STARTBM;
break;
default:
return -EINVAL;
}
@ -1045,6 +1048,7 @@ static int snd_intel8x0_pcm_prepare(struct snd_pcm_substream *substream)
ichdev->pos_shift = (runtime->sample_bits > 16) ? 2 : 1;
}
snd_intel8x0_setup_periods(chip, ichdev);
ichdev->jiffy_to_bytes = (runtime->rate * 4 * ichdev->pos_shift) / HZ;
return 0;
}
@ -1053,7 +1057,7 @@ static snd_pcm_uframes_t snd_intel8x0_pcm_pointer(struct snd_pcm_substream *subs
struct intel8x0 *chip = snd_pcm_substream_chip(substream);
struct ichdev *ichdev = get_ichdev(substream);
size_t ptr1, ptr;
int civ, timeout = 100;
int civ, timeout = 10;
unsigned int position;
spin_lock(&chip->reg_lock);
@ -1069,9 +1073,19 @@ static snd_pcm_uframes_t snd_intel8x0_pcm_pointer(struct snd_pcm_substream *subs
ptr1 == igetword(chip, ichdev->reg_offset + ichdev->roff_picb))
break;
} while (timeout--);
ptr1 <<= ichdev->pos_shift;
ptr = ichdev->fragsize1 - ptr1;
ptr += position;
if (ptr1 != 0) {
ptr1 <<= ichdev->pos_shift;
ptr = ichdev->fragsize1 - ptr1;
ptr += position;
ichdev->last_pos = ptr;
ichdev->last_pos_jiffies = jiffies;
} else {
ptr1 = jiffies - ichdev->last_pos_jiffies;
if (ptr1)
ptr1 -= 1;
ptr = ichdev->last_pos + ptr1 * ichdev->jiffy_to_bytes;
ptr %= ichdev->size;
}
spin_unlock(&chip->reg_lock);
if (ptr >= ichdev->size)
return 0;
@ -2710,9 +2724,13 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip)
pos1 == igetword(chip, ichdev->reg_offset + ichdev->roff_picb))
break;
} while (timeout--);
pos = ichdev->fragsize1;
pos -= pos1 << ichdev->pos_shift;
pos += ichdev->position;
if (pos1 == 0) { /* oops, this value is not reliable */
pos = 0;
} else {
pos = ichdev->fragsize1;
pos -= pos1 << ichdev->pos_shift;
pos += ichdev->position;
}
chip->in_measurement = 0;
do_posix_clock_monotonic_gettime(&stop_time);
/* stop */
@ -2729,6 +2747,11 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip)
iputbyte(chip, port + ICH_REG_OFF_CR, ICH_RESETREGS);
spin_unlock_irq(&chip->reg_lock);
if (pos == 0) {
snd_printk(KERN_ERR "intel8x0: measure - unreliable DMA position..\n");
return;
}
pos /= 4;
t = stop_time.tv_sec - start_time.tv_sec;
t *= 1000000;