[alsa-devel] [PATCH] ASoC: davinci-mcasp: Add rule to constrain the minimum period size
The minimum period size (in frames) must be not lower than the FIFO size of McASP and in general too small period size would easily result underrun in applications as eDMA - the most common DMA servicing McASP have support for limited number of periods.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com --- Hi,
I have tried to use snd_pcm_hw_constraint_minmax(..., SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 64, 0)
but with that the refining code was not able to find suitable configuration.
Regards, Peter
sound/soc/davinci/davinci-mcasp.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c index 51c61a6861af..ba4da45902b8 100644 --- a/sound/soc/davinci/davinci-mcasp.c +++ b/sound/soc/davinci/davinci-mcasp.c @@ -1263,6 +1263,20 @@ static int davinci_mcasp_hw_rule_format(struct snd_pcm_hw_params *params, return snd_mask_refine(fmt, &nfmt); }
+static int davinci_mcasp_hw_rule_min_periodsize( + struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) +{ + struct snd_interval *period_size = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE); + struct snd_interval frames; + + snd_interval_any(&frames); + frames.min = 64; + frames.integer = 1; + + return snd_interval_refine(period_size, &frames); +} + static int davinci_mcasp_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { @@ -1354,6 +1368,11 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream, return ret; }
+ snd_pcm_hw_rule_add(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, + davinci_mcasp_hw_rule_min_periodsize, NULL, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1); + return 0; }
The patch
ASoC: davinci-mcasp: Add rule to constrain the minimum period size
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From d43c17daf2771f703bd92a78b34c7b0f3dcc9576 Mon Sep 17 00:00:00 2001
From: Peter Ujfalusi peter.ujfalusi@ti.com Date: Fri, 5 Jan 2018 12:18:07 +0200 Subject: [PATCH] ASoC: davinci-mcasp: Add rule to constrain the minimum period size
The minimum period size (in frames) must be not lower than the FIFO size of McASP and in general too small period size would easily result underrun in applications as eDMA - the most common DMA servicing McASP have support for limited number of periods.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/davinci/davinci-mcasp.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c index 804c6f2bcf21..03ba218160ca 100644 --- a/sound/soc/davinci/davinci-mcasp.c +++ b/sound/soc/davinci/davinci-mcasp.c @@ -1242,6 +1242,20 @@ static int davinci_mcasp_hw_rule_format(struct snd_pcm_hw_params *params, return snd_mask_refine(fmt, &nfmt); }
+static int davinci_mcasp_hw_rule_min_periodsize( + struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) +{ + struct snd_interval *period_size = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE); + struct snd_interval frames; + + snd_interval_any(&frames); + frames.min = 64; + frames.integer = 1; + + return snd_interval_refine(period_size, &frames); +} + static int davinci_mcasp_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { @@ -1333,6 +1347,11 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream, return ret; }
+ snd_pcm_hw_rule_add(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, + davinci_mcasp_hw_rule_min_periodsize, NULL, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1); + return 0; }
participants (2)
-
Mark Brown -
Peter Ujfalusi