1 files changed, 33 insertions, 10 deletions

diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
index c86ff499460..6962f94d1be 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -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;