| Message ID | 20210407145714.311138-1-jbrunet@baylibre.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6f68accaa8641b70b698da659216f82f87537869 |
| Headers | show |
| Series | ASoC: meson: axg-frddr: set fifo depth according to the period | expand |
On Wed, 7 Apr 2021 16:57:14 +0200, Jerome Brunet wrote: > When the period is small, using all the FRDDR fifo depth increases the > latency of the playback because the following device won't start pulling > data until the fifo reaches the depth set. We can adjust this depth so trim > it down for small periods. Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next Thanks! [1/1] ASoC: meson: axg-frddr: set fifo depth according to the period commit: 6f68accaa8641b70b698da659216f82f87537869 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
diff --git a/sound/soc/meson/axg-frddr.c b/sound/soc/meson/axg-frddr.c index c3ae8ac30745..8ed114de0bdf 100644 --- a/sound/soc/meson/axg-frddr.c +++ b/sound/soc/meson/axg-frddr.c @@ -11,6 +11,7 @@ #include <linux/regmap.h> #include <linux/module.h> #include <linux/of_platform.h> +#include <sound/pcm_params.h> #include <sound/soc.h> #include <sound/soc-dai.h> @@ -46,11 +47,28 @@ static int g12a_frddr_dai_prepare(struct snd_pcm_substream *substream, return 0; } +static int axg_frddr_dai_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, + struct snd_soc_dai *dai) +{ + struct axg_fifo *fifo = snd_soc_dai_get_drvdata(dai); + unsigned int period, depth, val; + + period = params_period_bytes(params); + + /* Trim the FIFO depth if the period is small to improve latency */ + depth = min(period, fifo->depth); + val = (depth / AXG_FIFO_BURST) - 1; + regmap_update_bits(fifo->map, FIFO_CTRL1, CTRL1_FRDDR_DEPTH_MASK, + CTRL1_FRDDR_DEPTH(val)); + + return 0; +} + static int axg_frddr_dai_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct axg_fifo *fifo = snd_soc_dai_get_drvdata(dai); - unsigned int val; int ret; /* Enable pclk to access registers and clock the fifo ip */ @@ -61,11 +79,6 @@ static int axg_frddr_dai_startup(struct snd_pcm_substream *substream, /* Apply single buffer mode to the interface */ regmap_update_bits(fifo->map, FIFO_CTRL0, CTRL0_FRDDR_PP_MODE, 0); - /* Use all fifo depth */ - val = (fifo->depth / AXG_FIFO_BURST) - 1; - regmap_update_bits(fifo->map, FIFO_CTRL1, CTRL1_FRDDR_DEPTH_MASK, - CTRL1_FRDDR_DEPTH(val)); - return 0; } @@ -84,6 +97,7 @@ static int axg_frddr_pcm_new(struct snd_soc_pcm_runtime *rtd, } static const struct snd_soc_dai_ops axg_frddr_ops = { + .hw_params = axg_frddr_dai_hw_params, .startup = axg_frddr_dai_startup, .shutdown = axg_frddr_dai_shutdown, };
When the period is small, using all the FRDDR fifo depth increases the latency of the playback because the following device won't start pulling data until the fifo reaches the depth set. We can adjust this depth so trim it down for small periods. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> --- sound/soc/meson/axg-frddr.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)