3 files changed, 33 insertions, 5 deletions

diff --git a/sound/pci/emu10k1/emu10k1.c b/sound/pci/emu10k1/emu10k1.c
index 4203782d7cb..aff8387c45c 100644
--- a/sound/pci/emu10k1/emu10k1.c
+++ b/sound/pci/emu10k1/emu10k1.c
@@ -52,6 +52,7 @@ static int max_synth_voices[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 64};
 static int max_buffer_size[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 128};
 static int enable_ir[SNDRV_CARDS];
 static uint subsystem[SNDRV_CARDS]; /* Force card subsystem model */
+static uint delay_pcm_irq[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
 
 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for the EMU10K1 soundcard.");
@@ -73,6 +74,8 @@ module_param_array(enable_ir, bool, NULL, 0444);
 MODULE_PARM_DESC(enable_ir, "Enable IR.");
 module_param_array(subsystem, uint, NULL, 0444);
 MODULE_PARM_DESC(subsystem, "Force card subsystem model.");
+module_param_array(delay_pcm_irq, uint, NULL, 0444);
+MODULE_PARM_DESC(delay_pcm_irq, "Delay PCM interrupt by specified number of samples (default 0).");
 /*
  * Class 0401: 1102:0008 (rev 00) Subsystem: 1102:1001 -> Audigy2 Value  Model:SB0400
  */
@@ -127,6 +130,7 @@ static int __devinit snd_card_emu10k1_probe(struct pci_dev *pci,
                                       &emu)) < 0)
                 goto error;
         card->private_data = emu;
+        emu->delay_pcm_irq = delay_pcm_irq[dev] & 0x1f;
         if ((err = snd_emu10k1_pcm(emu, 0, NULL)) < 0)
                 goto error;
         if ((err = snd_emu10k1_pcm_mic(emu, 1, NULL)) < 0)
diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c
index 55b83ef73c6..622bace148e 100644
--- a/sound/pci/emu10k1/emupcm.c
+++ b/sound/pci/emu10k1/emupcm.c
@@ -332,7 +332,7 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
                 evoice->epcm->ccca_start_addr = start_addr + ccis;
                 if (extra) {
                         start_addr += ccis;
-                        end_addr += ccis;
+                        end_addr += ccis + emu->delay_pcm_irq;
                 }
                 if (stereo && !extra) {
                         snd_emu10k1_ptr_write(emu, CPF, voice, CPF_STEREO_MASK);
@@ -360,7 +360,9 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
         /* Assumption that PT is already 0 so no harm overwriting */
         snd_emu10k1_ptr_write(emu, PTRX, voice, (send_amount[0] << 8) | send_amount[1]);
         snd_emu10k1_ptr_write(emu, DSL, voice, end_addr | (send_amount[3] << 24));
-        snd_emu10k1_ptr_write(emu, PSST, voice, start_addr | (send_amount[2] << 24));
+        snd_emu10k1_ptr_write(emu, PSST, voice,
+                        (start_addr + (extra ? emu->delay_pcm_irq : 0)) |
+                        (send_amount[2] << 24));
         if (emu->card_capabilities->emu_model)
                 pitch_target = PITCH_48000; /* Disable interpolators on emu1010 card */
         else 
@@ -732,6 +734,23 @@ static void snd_emu10k1_playback_stop_voice(struct snd_emu10k1 *emu, struct snd_
         snd_emu10k1_ptr_write(emu, IP, voice, 0);
 }
 
+static inline void snd_emu10k1_playback_mangle_extra(struct snd_emu10k1 *emu,
+                struct snd_emu10k1_pcm *epcm,
+                struct snd_pcm_substream *substream,
+                struct snd_pcm_runtime *runtime)
+{
+        unsigned int ptr, period_pos;
+
+        /* try to sychronize the current position for the interrupt
+           source voice */
+        period_pos = runtime->status->hw_ptr - runtime->hw_ptr_interrupt;
+        period_pos %= runtime->period_size;
+        ptr = snd_emu10k1_ptr_read(emu, CCCA, epcm->extra->number);
+        ptr &= ~0x00ffffff;
+        ptr |= epcm->ccca_start_addr + period_pos;
+        snd_emu10k1_ptr_write(emu, CCCA, epcm->extra->number, ptr);
+}
+
 static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream,
                                         int cmd)
 {
@@ -753,6 +772,8 @@ static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream,
                 /* follow thru */
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
         case SNDRV_PCM_TRIGGER_RESUME:
+                if (cmd == SNDRV_PCM_TRIGGER_PAUSE_RELEASE)
+                        snd_emu10k1_playback_mangle_extra(emu, epcm, substream, runtime);
                 mix = &emu->pcm_mixer[substream->number];
                 snd_emu10k1_playback_prepare_voice(emu, epcm->voices[0], 1, 0, mix);
                 snd_emu10k1_playback_prepare_voice(emu, epcm->voices[1], 0, 0, mix);
@@ -869,8 +890,9 @@ static snd_pcm_uframes_t snd_emu10k1_playback_pointer(struct snd_pcm_substream *
 #endif
         /*
         printk(KERN_DEBUG
-               "ptr = 0x%x, buffer_size = 0x%x, period_size = 0x%x\n",
-               ptr, runtime->buffer_size, runtime->period_size);
+               "ptr = 0x%lx, buffer_size = 0x%lx, period_size = 0x%lx\n",
+               (long)ptr, (long)runtime->buffer_size,
+               (long)runtime->period_size);
         */
         return ptr;
 }
diff --git a/sound/pci/emu10k1/memory.c b/sound/pci/emu10k1/memory.c
index ffb1ddb8dc2..957a311514c 100644
--- a/sound/pci/emu10k1/memory.c
+++ b/sound/pci/emu10k1/memory.c
@@ -310,8 +310,10 @@ snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *subst
         if (snd_BUG_ON(!hdr))
                 return NULL;
 
+        idx = runtime->period_size >= runtime->buffer_size ?
+                                        (emu->delay_pcm_irq * 2) : 0;
         mutex_lock(&hdr->block_mutex);
-        blk = search_empty(emu, runtime->dma_bytes);
+        blk = search_empty(emu, runtime->dma_bytes + idx);
         if (blk == NULL) {
                 mutex_unlock(&hdr->block_mutex);
                 return NULL;