On 2/6/17 1:01 PM, Takashi Iwai wrote:
On Sat, 04 Feb 2017 08:57:08 +0100, Takashi Iwai wrote:
In anyway, it'd be appreciated if you can test on your hardware. I could test only on a single machine.
I can test more but only in 10 days from now so if we could delay this patch a bit it'd be better.
OK, I can postpone this change and keep BATCH and DOUBLE.
I've tested more intensively, and this seems working well, so far. Hopefully the DMA FIFO or fetch timing doesn't play a big role.
As I mentioned in the other email, the FIFO can be up to 512 bytes so beware. And it makes sense to limit the period size to 1024 bytes minimum.
BTW, with the combination of this and the latest my PCM rewrite patch, a more interesting experiment can be done: extend to (a kind of) no-period-wakeup mode. Of course, it doesn't work like HD-audio, as we can't the ring buffer persistently on LPE audio but have to refresh the buffer descriptors. But the refresh of BDs is also done at PCM pointer callback, so it would work as is. For supporting the case period=1, though, another trick is needed: namely, we set up 4 BDs pointing to the same address, so that it won't go out to underrun.'
Both the pseudo-no-period-wakeup and single period should work but I am not sure how useful this is.
A totally untested patch is below.
thanks,
Takashi
diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c index 0bd77acb9689..be9cabc9f58b 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -133,7 +133,8 @@ static const struct channel_map_table map_tables[] = { static const struct snd_pcm_hardware had_pcm_hardware = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP|
SNDRV_PCM_INFO_MMAP_VALID),
SNDRV_PCM_INFO_MMAP_VALID|SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),@@ -853,7 +854,9 @@ static void had_prog_bd(struct snd_pcm_substream *substream, int ofs = intelhaddata->pcmbuf_filled * intelhaddata->period_bytes; u32 addr = substream->runtime->dma_addr + ofs;
- addr |= AUD_BUF_VALID | AUD_BUF_INTR_EN;
- addr |= AUD_BUF_VALID;
- if (!subsream->runtime->no_period_wakeup)
addr |= AUD_BUF_INTR_EN;@@ -881,7 +884,10 @@ static void had_init_ringbuf(struct snd_pcm_substream *substream, int i, num_periods;
num_periods = runtime->periods;
- intelhaddata->num_bds = min(num_periods, HAD_NUM_OF_RING_BUFS);
- if (num_periods == 1)
intelhaddata->num_bds = HAD_NUM_OF_RING_BUFS;- else
intelhaddata->num_bds = min(num_periods, HAD_NUM_OF_RING_BUFS);@@ -891,7 +897,7 @@ static void had_init_ringbuf(struct snd_pcm_substream *substream, intelhaddata->pcmbuf_filled = 0;
for (i = 0; i < HAD_NUM_OF_RING_BUFS; i++) {
if (i < num_periods)
if (i < num_periods || num_periods == 1) had_prog_bd(substream, intelhaddata);diff --git a/sound/x86/intel_hdmi_lpe_audio.h b/sound/x86/intel_hdmi_lpe_audio.h index ca4212dca94e..3c2befa721a4 100644 --- a/sound/x86/intel_hdmi_lpe_audio.h +++ b/sound/x86/intel_hdmi_lpe_audio.h @@ -32,7 +32,7 @@ #define HAD_MAX_BUFFER ((1024 * 1024 - 1) & ~0x3f) #define HAD_DEFAULT_BUFFER (600 * 1024) /* default prealloc size */ #define HAD_MAX_PERIODS 256 /* arbitrary, but should suffice */ -#define HAD_MIN_PERIODS 2 +#define HAD_MIN_PERIODS 1 #define HAD_MAX_PERIOD_BYTES ((HAD_MAX_BUFFER / HAD_MIN_PERIODS) & ~0x3f) #define HAD_MIN_PERIOD_BYTES 1024 /* might be smaller */ #define HAD_FIFO_SIZE 0 /* fifo not being used */ _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel