[ALSA] snd-hda-intel: use WALLCLK register to check for early irqs

[safe/jmp/linux-2.6] / sound / pci / hda / hda_intel.c

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index cad9b70..0a6c55b 100644 (file)
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -174,7 +174,7 @@ MODULE_DESCRIPTION("Intel HDA driver");
 #define   ICH6_GSTS_FSTS       (1 << 1)   /* flush status */
 #define ICH6_REG_INTCTL                        0x20
 #define ICH6_REG_INTSTS                        0x24
-#define ICH6_REG_WALCLK                        0x30
+#define ICH6_REG_WALLCLK               0x30    /* 24Mhz source */
 #define ICH6_REG_SYNC                  0x34    
 #define ICH6_REG_CORBLBASE             0x40
 #define ICH6_REG_CORBUBASE             0x44
@@ -340,8 +340,8 @@ 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 long start_jiffies;    /* start + minimum jiffies */
-       unsigned long min_jiffies;      /* minimum jiffies before position is valid */
+       unsigned long start_wallclk;    /* start + minimum wallclk */
+       unsigned long period_wallclk;   /* wallclk for period */
 
        void __iomem *sd_addr;  /* stream descriptor pointer */
 
@@ -361,7 +361,6 @@ struct azx_dev {
        unsigned int opened :1;
        unsigned int running :1;
        unsigned int irq_pending :1;
-       unsigned int start_flag: 1;     /* stream full start flag */
        /*
         * For VIA:
         *  A flag to ensure DMA position is 0
@@ -1676,8 +1675,9 @@ static int azx_pcm_prepare(struct snd_pcm_substream *substream)
                        return err;
        }
 
-       azx_dev->min_jiffies = (runtime->period_size * HZ) /
-                                               (runtime->rate * 2);
+       /* wallclk has 24Mhz clock source */
+       azx_dev->period_wallclk = (((runtime->period_size * 24000) /
+                                               runtime->rate) * 1000);
        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;
@@ -1731,14 +1731,15 @@ 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)
+               if (start) {
+                       azx_dev->start_wallclk = azx_readl(chip, WALLCLK);
+                       if (!rstart)
+                               azx_dev->start_wallclk -=
+                                               azx_dev->period_wallclk;
                        azx_stream_start(chip, azx_dev);
-               else
+               } else {
                        azx_stream_stop(chip, azx_dev);
+               }
                azx_dev->running = start;
        }
        spin_unlock(&chip->reg_lock);
@@ -1885,13 +1886,14 @@ static snd_pcm_uframes_t azx_pcm_pointer(struct snd_pcm_substream *substream)
  */
 static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
 {
+       u32 wallclk;
        unsigned int pos;
        int stream;
 
-       if (azx_dev->start_flag &&
-           time_before_eq(jiffies, azx_dev->start_jiffies))
+       wallclk = azx_readl(chip, WALLCLK);
+       if ((wallclk - azx_dev->start_wallclk) <
+                               (azx_dev->period_wallclk * 2) / 3)
                return -1;      /* bogus (too early) interrupt */
-       azx_dev->start_flag = 0;
 
        stream = azx_dev->substream->stream;
        pos = azx_get_position(chip, azx_dev);
@@ -1906,13 +1908,12 @@ static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
                        chip->position_fix[stream] = POS_FIX_POSBUF;
        }
 
-       if (!bdl_pos_adj[chip->dev_index])
-               return 1; /* no delayed ack */
        if (WARN_ONCE(!azx_dev->period_bytes,
                      "hda-intel: zero azx_dev->period_bytes"))
                return 0; /* this shouldn't happen! */
        if (pos % azx_dev->period_bytes > azx_dev->period_bytes / 2)
                return 0; /* NG - it's below the period boundary */
+       azx_dev->start_wallclk = wallclk;
        return 1; /* OK, it's fine */
 }
 
@@ -1922,7 +1923,7 @@ static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
 static void azx_irq_pending_work(struct work_struct *work)
 {
        struct azx *chip = container_of(work, struct azx, irq_pending_work);
-       int i, pending;
+       int i, pending, ok;
 
        if (!chip->irq_pending_warned) {
                printk(KERN_WARNING
@@ -1941,11 +1942,14 @@ static void azx_irq_pending_work(struct work_struct *work)
                            !azx_dev->substream ||
                            !azx_dev->running)
                                continue;
-                       if (azx_position_ok(chip, azx_dev)) {
+                       ok = azx_position_ok(chip, azx_dev);
+                       if (ok > 0) {
                                azx_dev->irq_pending = 0;
                                spin_unlock(&chip->reg_lock);
                                snd_pcm_period_elapsed(azx_dev->substream);
                                spin_lock(&chip->reg_lock);
+                       } else if (ok < 0) {
+                               pending = 0;    /* too early */
                        } else
                                pending++;
                }