[alsa-devel] [PATCH 1/3] ALSA: hda - force use of SSYNC bits
SSYNC bits are typically used to start multiple streams synchronously. It makes sense to use them for a single stream for a more predictable startup sequence. The transfers only start once the DMA and FIFOs are ready. This results in a better correlation between timestamps and number of samples played.
Credits to Kar Leong Wang for suggesting this improvement.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/pci/hda/hda_intel.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 60882c6..7ba187e 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1959,14 +1959,14 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) }
spin_lock(&chip->reg_lock); - if (nsync > 1) { - /* first, set SYNC bits of corresponding streams */ - if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC) - azx_writel(chip, OLD_SSYNC, - azx_readl(chip, OLD_SSYNC) | sbits); - else - azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) | sbits); - } + + /* first, set SYNC bits of corresponding streams */ + if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC) + azx_writel(chip, OLD_SSYNC, + azx_readl(chip, OLD_SSYNC) | sbits); + else + azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) | sbits); + snd_pcm_group_for_each_entry(s, substream) { if (s->pcm->card != substream->pcm->card) continue; @@ -1984,8 +1984,6 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) } spin_unlock(&chip->reg_lock); if (start) { - if (nsync == 1) - return 0; /* wait until all FIFOs get ready */ for (timeout = 5000; timeout; timeout--) { nwait = 0; @@ -2018,16 +2016,14 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) cpu_relax(); } } - if (nsync > 1) { - spin_lock(&chip->reg_lock); - /* reset SYNC bits */ - if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC) - azx_writel(chip, OLD_SSYNC, - azx_readl(chip, OLD_SSYNC) & ~sbits); - else - azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) & ~sbits); - spin_unlock(&chip->reg_lock); - } + spin_lock(&chip->reg_lock); + /* reset SYNC bits */ + if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC) + azx_writel(chip, OLD_SSYNC, + azx_readl(chip, OLD_SSYNC) & ~sbits); + else + azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) & ~sbits); + spin_unlock(&chip->reg_lock); return 0; }
DMA Position in Buffer (DPIB) should be used for ring buffer management, while LPIB register provides information on the number of samples transfered on the link. The difference between the two pieces of information corresponds to hardware/DMA buffering.
This patch reports this difference in runtime->delay, and removes the use of the COMBO mode on recent Intel hardware.
Credits to Takashi Iwai for an initial patch.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/pci/hda/hda_intel.c | 34 ++++++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 7ba187e..acd6756 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -538,6 +538,7 @@ enum { #define AZX_DCAPS_ALIGN_BUFSIZE (1 << 22) /* buffer size alignment */ #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23) /* BDLE in 4k boundary */ #define AZX_DCAPS_POSFIX_COMBO (1 << 24) /* Use COMBO as default */ +#define AZX_DCAPS_COUNT_LPIB_DELAY (1 << 25) /* Take LPIB as delay */
/* quirks for ATI SB / AMD Hudson */ #define AZX_DCAPS_PRESET_ATI_SB \ @@ -2116,6 +2117,27 @@ static unsigned int azx_get_position(struct azx *chip,
if (pos >= azx_dev->bufsize) pos = 0; + + /* calculate runtime delay from LPIB */ + if (azx_dev->substream->runtime && + chip->position_fix[stream] == POS_FIX_POSBUF && + (chip->driver_caps & AZX_DCAPS_COUNT_LPIB_DELAY)) { + unsigned int lpib_pos = azx_sd_readl(azx_dev, SD_LPIB); + int delay; + if (stream == SNDRV_PCM_STREAM_PLAYBACK) + delay = pos - lpib_pos; + else + delay = lpib_pos - pos; + if (delay < 0) + delay += azx_dev->bufsize; + if (delay >= azx_dev->period_bytes) { + snd_printk(KERN_ERR "delay %d > period_bytes %d\n", + delay, azx_dev->period_bytes); + delay = 0; /* something is wrong */ + } + azx_dev->substream->runtime->delay = + bytes_to_frames(azx_dev->substream->runtime, delay); + } return pos; }
@@ -3254,7 +3276,7 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = { /* CPT */ { PCI_DEVICE(0x8086, 0x1c20), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* PBG */ { PCI_DEVICE(0x8086, 0x1d20), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | @@ -3262,23 +3284,23 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = { /* Panther Point */ { PCI_DEVICE(0x8086, 0x1e20), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* Lynx Point */ { PCI_DEVICE(0x8086, 0x8c20), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* Lynx Point-LP */ { PCI_DEVICE(0x8086, 0x9c20), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* Lynx Point-LP */ { PCI_DEVICE(0x8086, 0x9c21), .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* Haswell */ { PCI_DEVICE(0x8086, 0x0c0c), .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP | - AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO }, + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* SCH */ { PCI_DEVICE(0x8086, 0x811b), .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP |
Tested with LPIB delay without any issues.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/pci/hda/hda_intel.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index acd6756..b682442 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -3301,6 +3301,10 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = { { PCI_DEVICE(0x8086, 0x0c0c), .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP | AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, + /* 5 Series/3400 */ + { PCI_DEVICE(0x8086, 0x3b56), + .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP | + AZX_DCAPS_BUFSIZE | AZX_DCAPS_COUNT_LPIB_DELAY }, /* SCH */ { PCI_DEVICE(0x8086, 0x811b), .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP |
At Fri, 21 Sep 2012 18:39:05 -0500, Pierre-Louis Bossart wrote:
SSYNC bits are typically used to start multiple streams synchronously. It makes sense to use them for a single stream for a more predictable startup sequence. The transfers only start once the DMA and FIFOs are ready. This results in a better correlation between timestamps and number of samples played.
Credits to Kar Leong Wang for suggesting this improvement.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Since all my tests with a few Intel machines passed, I applied all patches with minor modification for next-branch tree now.
Thanks!
Takashi
sound/pci/hda/hda_intel.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 60882c6..7ba187e 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1959,14 +1959,14 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) }
spin_lock(&chip->reg_lock);
- if (nsync > 1) {
/* first, set SYNC bits of corresponding streams */if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC)azx_writel(chip, OLD_SSYNC,azx_readl(chip, OLD_SSYNC) | sbits);elseazx_writel(chip, SSYNC, azx_readl(chip, SSYNC) | sbits);- }
- /* first, set SYNC bits of corresponding streams */
- if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC)
azx_writel(chip, OLD_SSYNC,azx_readl(chip, OLD_SSYNC) | sbits);- else
azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) | sbits);- snd_pcm_group_for_each_entry(s, substream) { if (s->pcm->card != substream->pcm->card) continue;
@@ -1984,8 +1984,6 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) } spin_unlock(&chip->reg_lock); if (start) {
if (nsync == 1)return 0;@@ -2018,16 +2016,14 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd) cpu_relax(); } }
- if (nsync > 1) {
spin_lock(&chip->reg_lock);/* reset SYNC bits */if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC)azx_writel(chip, OLD_SSYNC,azx_readl(chip, OLD_SSYNC) & ~sbits);elseazx_writel(chip, SSYNC, azx_readl(chip, SSYNC) & ~sbits);spin_unlock(&chip->reg_lock);- }
- spin_lock(&chip->reg_lock);
- /* reset SYNC bits */
- if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC)
azx_writel(chip, OLD_SSYNC,azx_readl(chip, OLD_SSYNC) & ~sbits);- else
azx_writel(chip, SSYNC, azx_readl(chip, SSYNC) & ~sbits);- spin_unlock(&chip->reg_lock); return 0;
}
-- 1.7.9.5
Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
participants (2)
-
Pierre-Louis Bossart -
Takashi Iwai