[ALSA] hda_intel: fix unexpected ring buffer positions

I found two issues with ICH7-M (it should be related to other HDA chipsets
as well):

- the ring buffer position is not reset when stream restarts (after xrun) -
  solved by moving azx_stream_reset() call from open() to prepare() callback
  and reset posbuf to zero (it might be filled with hw later than position()
  callback is called)
- irq_ignore flag should be set also when ring buffer memory area is not
  changed in prepare() callback - this patch replaces irq_ignore with
  more universal check based on jiffies clock

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 25 insertions, 14 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 30829ee920c3..6d3b927e0f84 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -312,6 +312,9 @@ struct azx_dev {
         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 */
+        unsigned int start_flag: 1;     /* stream full start flag */
+        unsigned long start_jiffies;    /* start + minimum jiffies */
+        unsigned long min_jiffies;      /* minimum jiffies before position is valid */
 
         void __iomem *sd_addr;  /* stream descriptor pointer */
 
@@ -330,7 +333,6 @@ struct azx_dev {
         unsigned int opened :1;
         unsigned int running :1;
         unsigned int irq_pending :1;
-        unsigned int irq_ignore :1;
         /*
          * For VIA:
          *  A flag to ensure DMA position is 0
@@ -975,7 +977,7 @@ static irqreturn_t azx_interrupt(int irq, void *dev_id)
         struct azx *chip = dev_id;
         struct azx_dev *azx_dev;
         u32 status;
-        int i;
+        int i, ok;
 
         spin_lock(&chip->reg_lock);
 
@@ -991,18 +993,14 @@ static irqreturn_t azx_interrupt(int irq, void *dev_id)
                         azx_sd_writeb(azx_dev, SD_STS, SD_INT_MASK);
                         if (!azx_dev->substream || !azx_dev->running)
                                 continue;
-                        /* ignore the first dummy IRQ (due to pos_adj) */
-                        if (azx_dev->irq_ignore) {
-                                azx_dev->irq_ignore = 0;
-                                continue;
-                        }
                         /* check whether this IRQ is really acceptable */
-                        if (azx_position_ok(chip, azx_dev)) {
+                        ok = azx_position_ok(chip, azx_dev);
+                        if (ok == 1) {
                                 azx_dev->irq_pending = 0;
                                 spin_unlock(&chip->reg_lock);
                                 snd_pcm_period_elapsed(azx_dev->substream);
                                 spin_lock(&chip->reg_lock);
-                        } else if (chip->bus && chip->bus->workq) {
+                        } else if (ok == 0 && chip->bus && chip->bus->workq) {
                                 /* bogus IRQ, process it later */
                                 azx_dev->irq_pending = 1;
                                 queue_work(chip->bus->workq,
@@ -1088,7 +1086,6 @@ static int azx_setup_periods(struct azx *chip,
         bdl = (u32 *)azx_dev->bdl.area;
         ofs = 0;
         azx_dev->frags = 0;
-        azx_dev->irq_ignore = 0;
         pos_adj = bdl_pos_adj[chip->dev_index];
         if (pos_adj > 0) {
                 struct snd_pcm_runtime *runtime = substream->runtime;
@@ -1109,7 +1106,6 @@ static int azx_setup_periods(struct azx *chip,
                                          &bdl, ofs, pos_adj, 1);
                         if (ofs < 0)
                                 goto error;
-                        azx_dev->irq_ignore = 1;
                 }
         } else
                 pos_adj = 0;
@@ -1155,6 +1151,9 @@ static void azx_stream_reset(struct azx *chip, struct azx_dev *azx_dev)
         while (((val = azx_sd_readb(azx_dev, SD_CTL)) & SD_CTL_STREAM_RESET) &&
                --timeout)
                 ;
+
+        /* reset first position - may not be synced with hw at this time */
+        *azx_dev->posbuf = 0;
 }
 
 /*
@@ -1409,7 +1408,6 @@ static int azx_pcm_open(struct snd_pcm_substream *substream)
         snd_pcm_set_sync(substream);
         mutex_unlock(&chip->open_mutex);
 
-        azx_stream_reset(chip, azx_dev);
         return 0;
 }
 
@@ -1474,6 +1472,7 @@ static int azx_pcm_prepare(struct snd_pcm_substream *substream)
         unsigned int bufsize, period_bytes, format_val;
         int err;
 
+        azx_stream_reset(chip, azx_dev);
         format_val = snd_hda_calc_stream_format(runtime->rate,
                                                 runtime->channels,
                                                 runtime->format,
@@ -1502,6 +1501,8 @@ static int azx_pcm_prepare(struct snd_pcm_substream *substream)
                         return err;
         }
 
+        azx_dev->min_jiffies = (runtime->period_size * HZ) /
+                                                (runtime->rate * 2);
         azx_setup_controller(chip, azx_dev);
         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                 azx_dev->fifo_size = azx_sd_readw(azx_dev, SD_FIFOSIZE) + 1;
@@ -1518,13 +1519,14 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
         struct azx *chip = apcm->chip;
         struct azx_dev *azx_dev;
         struct snd_pcm_substream *s;
-        int start, nsync = 0, sbits = 0;
+        int rstart = 0, start, nsync = 0, sbits = 0;
         int nwait, timeout;
 
         switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                rstart = 1;
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
         case SNDRV_PCM_TRIGGER_RESUME:
-        case SNDRV_PCM_TRIGGER_START:
                 start = 1;
                 break;
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
@@ -1554,6 +1556,10 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
                 if (s->pcm->card != substream->pcm->card)
                         continue;
                 azx_dev = get_azx_dev(s);
+                if (rstart) {
+                        azx_dev->start_flag = 1;
+                        azx_dev->start_jiffies = jiffies + azx_dev->min_jiffies;
+                }
                 if (start)
                         azx_stream_start(chip, azx_dev);
                 else
@@ -1703,6 +1709,11 @@ static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
 {
         unsigned int pos;
 
+        if (azx_dev->start_flag &&
+            time_before_eq(jiffies, azx_dev->start_jiffies))
+                return -1;      /* bogus (too early) interrupt */
+        azx_dev->start_flag = 0;
+
         pos = azx_get_position(chip, azx_dev);
         if (chip->position_fix == POS_FIX_AUTO) {
                 if (!pos) {