[ALSA] Add position_fix module option

Documentation,HDA Intel driver
Added position_fix module option to HDA-intel driver for fixing up
the DMA position (possibly hardware-) bugs.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 57 insertions, 37 deletions

diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index c69581ca2a34..ef07506e583c 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -618,6 +618,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     Module for Intel HD Audio (ICH6, ICH6M, ICH7)
 
     model       - force the model name
+    position_fix - Fix DMA pointer (0 = FIFO size, 1 = none, 2 = POSBUF)
 
     Module supports up to 8 cards.
 
@@ -643,6 +644,14 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
           full_dig      6-jack in back, 2-jack in front, SPDIF I/O
           allout        5-jack in back, 2-jack in front, SPDIF out
 
+    Note 2: If you get click noises on output, try the module option
+            position_fix=1 or 2.  position_fix=1 will use the SD_LPIB
+            register value without FIFO size correction as the current
+            DMA pointer.  position_fix=2 will make the driver to use
+            the position buffer instead of reading SD_LPIB register.
+            (Usually SD_LPLIB register is more accurate than the
+            position buffer.)
+
   Module snd-hdsp
   ---------------
 
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index cbc9ca73c2ab..104593fa08eb 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -51,6 +51,7 @@ static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
 static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
 static char *model[SNDRV_CARDS];
+static int position_fix[SNDRV_CARDS];
 
 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for Intel HD audio interface.");
@@ -60,6 +61,8 @@ module_param_array(enable, bool, NULL, 0444);
 MODULE_PARM_DESC(enable, "Enable Intel HD audio interface.");
 module_param_array(model, charp, NULL, 0444);
 MODULE_PARM_DESC(model, "Use the given board model.");
+module_param_array(position_fix, bool, NULL, 0444);
+MODULE_PARM_DESC(position_fix, "Fix DMA pointer (0 = FIFO size, 1 = none, 2 = POSBUF).");
 
 MODULE_LICENSE("GPL");
 MODULE_SUPPORTED_DEVICE("{{Intel, ICH6},"
@@ -183,6 +186,12 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 };
 #define ICH6_MAX_CORB_ENTRIES   256
 #define ICH6_MAX_RIRB_ENTRIES   256
 
+/* position fix mode */
+enum {
+        POS_FIX_FIFO,
+        POS_FIX_NONE,
+        POS_FIX_POSBUF
+};
 
 /*
  * Use CORB/RIRB for communication from/to codecs.
@@ -191,12 +200,6 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 };
 #define USE_CORB_RIRB
 
 /*
- * Define this if use the position buffer instead of reading SD_LPIB
- * It's not used as default since SD_LPIB seems to give more accurate position
- */
-/* #define USE_POSBUF */
-
-/*
  */
 
 typedef struct snd_azx azx_t;
@@ -271,6 +274,9 @@ struct snd_azx {
         struct snd_dma_buffer bdl;
         struct snd_dma_buffer rb;
         struct snd_dma_buffer posbuf;
+
+        /* flags */
+        int position_fix;
 };
 
 /*
@@ -657,11 +663,11 @@ static void azx_init_chip(azx_t *chip)
         /* initialize the codec command I/O */
         azx_init_cmd_io(chip);
 
-#ifdef USE_POSBUF
-        /* program the position buffer */
-        azx_writel(chip, DPLBASE, (u32)chip->posbuf.addr);
-        azx_writel(chip, DPUBASE, upper_32bit(chip->posbuf.addr));
-#endif
+        if (chip->position_fix == POS_FIX_POSBUF) {
+                /* program the position buffer */
+                azx_writel(chip, DPLBASE, (u32)chip->posbuf.addr);
+                azx_writel(chip, DPUBASE, upper_32bit(chip->posbuf.addr));
+        }
 }
 
 
@@ -791,11 +797,12 @@ static int azx_setup_controller(azx_t *chip, azx_dev_t *azx_dev)
         /* upper BDL address */
         azx_sd_writel(azx_dev, SD_BDLPU, upper_32bit(azx_dev->bdl_addr));
 
-#ifdef USE_POSBUF
-        /* enable the position buffer */
-        if (! (azx_readl(chip, DPLBASE) & ICH6_DPLBASE_ENABLE))
-                azx_writel(chip, DPLBASE, (u32)chip->posbuf.addr | ICH6_DPLBASE_ENABLE);
-#endif
+        if (chip->position_fix == POS_FIX_POSBUF) {
+                /* enable the position buffer */
+                if (! (azx_readl(chip, DPLBASE) & ICH6_DPLBASE_ENABLE))
+                        azx_writel(chip, DPLBASE, (u32)chip->posbuf.addr | ICH6_DPLBASE_ENABLE);
+        }
+
         /* set the interrupt enable bits in the descriptor control register */
         azx_sd_writel(azx_dev, SD_CTL, azx_sd_readl(azx_dev, SD_CTL) | SD_INT_MASK);
 
@@ -1036,16 +1043,20 @@ static int azx_pcm_trigger(snd_pcm_substream_t *substream, int cmd)
 
 static snd_pcm_uframes_t azx_pcm_pointer(snd_pcm_substream_t *substream)
 {
+        struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+        azx_t *chip = apcm->chip;
         azx_dev_t *azx_dev = get_azx_dev(substream);
         unsigned int pos;
 
-#ifdef USE_POSBUF
-        /* use the position buffer */
-        pos = *azx_dev->posbuf;
-#else
-        /* read LPIB */
-        pos = azx_sd_readl(azx_dev, SD_LPIB) + azx_dev->fifo_size;
-#endif
+        if (chip->position_fix == POS_FIX_POSBUF) {
+                /* use the position buffer */
+                pos = *azx_dev->posbuf;
+        } else {
+                /* read LPIB */
+                pos = azx_sd_readl(azx_dev, SD_LPIB);
+                if (chip->position_fix == POS_FIX_FIFO)
+                        pos += azx_dev->fifo_size;
+        }
         if (pos >= azx_dev->bufsize)
                 pos = 0;
         return bytes_to_frames(substream->runtime, pos);
@@ -1155,9 +1166,8 @@ static int __devinit azx_init_stream(azx_t *chip)
                 azx_dev_t *azx_dev = &chip->azx_dev[i];
                 azx_dev->bdl = (u32 *)(chip->bdl.area + off);
                 azx_dev->bdl_addr = chip->bdl.addr + off;
-#ifdef USE_POSBUF
-                azx_dev->posbuf = (volatile u32 *)(chip->posbuf.area + i * 8);
-#endif
+                if (chip->position_fix == POS_FIX_POSBUF)
+                        azx_dev->posbuf = (volatile u32 *)(chip->posbuf.area + i * 8);
                 /* offset: SDI0=0x80, SDI1=0xa0, ... SDO3=0x160 */
                 azx_dev->sd_addr = chip->remap_addr + (0x20 * i + 0x80);
                 /* int mask: SDI0=0x01, SDI1=0x02, ... SDO3=0x80 */
@@ -1237,10 +1247,8 @@ static int azx_free(azx_t *chip)
                 snd_dma_free_pages(&chip->bdl);
         if (chip->rb.area)
                 snd_dma_free_pages(&chip->rb);
-#ifdef USE_POSBUF
         if (chip->posbuf.area)
                 snd_dma_free_pages(&chip->posbuf);
-#endif
         pci_release_regions(chip->pci);
         pci_disable_device(chip->pci);
         kfree(chip);
@@ -1256,7 +1264,8 @@ static int azx_dev_free(snd_device_t *device)
 /*
  * constructor
  */
-static int __devinit azx_create(snd_card_t *card, struct pci_dev *pci, azx_t **rchip)
+static int __devinit azx_create(snd_card_t *card, struct pci_dev *pci,
+                                int posfix, azx_t **rchip)
 {
         azx_t *chip;
         int err = 0;
@@ -1283,6 +1292,8 @@ static int __devinit azx_create(snd_card_t *card, struct pci_dev *pci, azx_t **r
         chip->pci = pci;
         chip->irq = -1;
 
+        chip->position_fix = posfix;
+
         if ((err = pci_request_regions(pci, "ICH HD audio")) < 0) {
                 kfree(chip);
                 pci_disable_device(pci);
@@ -1314,14 +1325,14 @@ static int __devinit azx_create(snd_card_t *card, struct pci_dev *pci, azx_t **r
                 snd_printk(KERN_ERR SFX "cannot allocate BDL\n");
                 goto errout;
         }
-#ifdef USE_POSBUF
-        /* allocate memory for the position buffer */
-        if ((err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(chip->pci),
-                                       MAX_ICH6_DEV * 8, &chip->posbuf)) < 0) {
-                snd_printk(KERN_ERR SFX "cannot allocate posbuf\n");
-                goto errout;
+        if (chip->position_fix == POS_FIX_POSBUF) {
+                /* allocate memory for the position buffer */
+                if ((err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(chip->pci),
+                                               MAX_ICH6_DEV * 8, &chip->posbuf)) < 0) {
+                        snd_printk(KERN_ERR SFX "cannot allocate posbuf\n");
+                        goto errout;
+                }
         }
-#endif
         /* allocate CORB/RIRB */
         if ((err = azx_alloc_cmd_io(chip)) < 0)
                 goto errout;
@@ -1372,7 +1383,7 @@ static int __devinit azx_probe(struct pci_dev *pci, const struct pci_device_id *
                 return -ENOMEM;
         }
 
-        if ((err = azx_create(card, pci, &chip)) < 0) {
+        if ((err = azx_create(card, pci, position_fix[dev], &chip)) < 0) {
                 snd_card_free(card);
                 return err;
         }