ASoc: kirkwood: Extend the min and max number of bytes per period
PATCH 1/1 ASoc: kirkwood: Extend the min and max number of bytes per period
This patch extends the min and max number of bytes per period. It mainly permits to reduce the sound delay in MIDI real-time playing.
--- sound/soc/kirkwood/kirkwood.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
sound/soc/kirkwood/kirkwood.h +2 -2
@@ -123,8 +123,8 @@/* need to find where they come from */ #define KIRKWOOD_SND_MIN_PERIODS 8#define KIRKWOOD_SND_MAX_PERIODS 16 -#define KIRKWOOD_SND_MIN_PERIOD_BYTES 0x4000 -#define KIRKWOOD_SND_MAX_PERIOD_BYTES 0x4000 +#define KIRKWOOD_SND_MIN_PERIOD_BYTES 0x800 +#define KIRKWOOD_SND_MAX_PERIOD_BYTES 0x8000#define KIRKWOOD_SND_MAX_BUFFER_BYTES (KIRKWOOD_SND_MAX_PERIOD_BYTES \ * KIRKWOOD_SND_MAX_PERIODS)
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Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ _______________________________________________ Alsa-devel mailing list [email protected] http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Mark Brown
maintainerQuoted 2 lines · Jean-Francois Moine
This patch extends the min and max number of bytes per period. It mainly permits to reduce the sound delay in MIDI real-time playing.
Applied, thanks. For the minimum limit is there any hardware imposed
limit that could be used rather than tweaking the numbers?
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Quoted 6 lines · Mark Brown
Quoted 2 lines · Jean-Francois Moine
This patch extends the min and max number of bytes per period. It mainly permits to reduce the sound delay in MIDI real-time playing.
Applied, thanks. For the minimum limit is there any hardware imposed limit that could be used rather than tweaking the numbers?
I looked at that, and apart from interrupt rate, I don't see any.
The values I have for these in my tree are:
#define KIRKWOOD_SND_MIN_PERIODS 2 #define KIRKWOOD_SND_MAX_PERIODS 16 #define KIRKWOOD_SND_MIN_PERIOD_BYTES 256 #define KIRKWOOD_SND_MAX_PERIOD_BYTES 0x100000 #define KIRKWOOD_SND_MAX_BUFFER_BYTES 0x100000
which are partly based on patches applied to Rabeeh's kernel, and then further adjusted. Yes, the max period bytes won't be reachable since the minimum period will cause it to be half the max buffer bytes.
Mark Brown
maintainerQuoted 11 lines · Russell King - ARM Linux
The values I have for these in my tree are:
#define KIRKWOOD_SND_MIN_PERIODS 2 #define KIRKWOOD_SND_MAX_PERIODS 16 #define KIRKWOOD_SND_MIN_PERIOD_BYTES 256 #define KIRKWOOD_SND_MAX_PERIOD_BYTES 0x100000 #define KIRKWOOD_SND_MAX_BUFFER_BYTES 0x100000which are partly based on patches applied to Rabeeh's kernel, and then further adjusted. Yes, the max period bytes won't be reachable since the minimum period will cause it to be half the max buffer bytes.
Those don't look implausible, obviously it'd be pretty CPU intensive
application that pushed down to the minima but perhaps someone is
willing to pay the cost. As you say the maximum buffer might want
tweaking (or perhaps the maximum period bytes).
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