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author | Oswald Buddenhagen <oswald.buddenhagen@gmx.de> | 2023-05-16 12:36:11 +0300 |
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committer | Takashi Iwai <tiwai@suse.de> | 2023-05-17 18:04:35 +0300 |
commit | 77e067d0fa0511daec7e4c72ec3f830e5faaee9e (patch) | |
tree | 1911452e67ec3b0aaf8d06b008f4ba09b74d4872 /include/sound/emu10k1.h | |
parent | 35a60d1edff4dec9a31862a3515676cd0fafe4e4 (diff) | |
download | linux-77e067d0fa0511daec7e4c72ec3f830e5faaee9e.tar.xz |
ALSA: emu10k1: skip needless setting of some voice registers
Many registers are meaningless for stereo slaves and the extra voices.
This patch cleans up these unnecessary register writes.
snd_emu10k1_playback_{trigger,stop}_voice() is not called for stereo
slaves any more.
snd_emu10k1_playback_prepare_voice() is renamed to
snd_emu10k1_playback_unmute_voice(), as this better reflects its
remaining function. It's not called for the extra voices any more.
Accordingly, snd_emu10k1_playback_mute_voice() is factored out from
snd_emu10k1_playback_stop_voice(), and is called selectively as well.
This doesn't add conditionals which would avoid initializing
sub-registers, as that wouldn't pull its weight.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230516093612.3536451-6-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/sound/emu10k1.h')
-rw-r--r-- | include/sound/emu10k1.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/sound/emu10k1.h b/include/sound/emu10k1.h index a5e935e16651..5c1e5b123362 100644 --- a/include/sound/emu10k1.h +++ b/include/sound/emu10k1.h @@ -404,6 +404,14 @@ SUB_REG(HCFG, LOCKTANKCACHE, 0x00000004) /* 1 = Cancel bustmaster accesses to ta // distortion), the modulation engine sets the target registers, towards // which the current registers "swerve" gradually. +// For the odd channel in a stereo pair, these registers are meaningless: +// CPF_STEREO, CPF_CURRENTPITCH, PTRX_PITCHTARGET, CCR_CACHEINVALIDSIZE, +// PSST_LOOPSTARTADDR, DSL_LOOPENDADDR, CCCA_CURRADDR +// The somewhat non-obviously still meaningful ones are: +// CPF_STOP, CPF_FRACADDRESS, CCR_READADDRESS (!), +// CCCA_INTERPROM, CCCA_8BITSELECT (!) +// (The envelope engine is ignored here, as stereo matters only for verbatim playback.) + #define CPF 0x00 /* Current pitch and fraction register */ SUB_REG(CPF, CURRENTPITCH, 0xffff0000) /* Current pitch (linear, 0x4000 == unity pitch shift) */ #define CPF_STEREO_MASK 0x00008000 /* 1 = Even channel interleave, odd channel locked */ |