Commit 08e55ae9 authored by Oswald Buddenhagen's avatar Oswald Buddenhagen Committed by Takashi Iwai
Browse files

ALSA: emu10k1: enable bit-exact playback, part 3: pitch 



CPF_CURRENTPITCH starts swerving towards PTRX_PITCHTARGET as soon as
that is set. In practice this means that CPF_FRACADDRESS may acquire a
non-zero value before we manage to force CPF_CURRENTPITCH to the final
value, which would prevent bit-for-bit reproduction.

To avoid that this state persists, we now reset CPF_FRACADDRESS when
setting CPF_CURRENTPITCH, and to (mostly) avoid that it progresses too
far in the first place (possibly even reaching CCCA_CURRADDR), we write
PTRX and CPF in one critical section (though NMIs, etc. still make this
unreliable).

Signed-off-by: default avatarOswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230518140339.3722279-2-oswald.buddenhagen@gmx.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 5c2664cc

sound/pci/emu10k1/emupcm.c

+13 −4
Original line number Diff line number Diff line
@@ -601,6 +601,17 @@ static void snd_emu10k1_playback_mute_voice(struct snd_emu10k1 *emu, 
	snd_emu10k1_playback_commit_volume(emu, evoice, 0);

}



static void snd_emu10k1_playback_commit_pitch(struct snd_emu10k1 *emu,

					      u32 voice, u32 pitch_target)

{

	u32 ptrx = snd_emu10k1_ptr_read(emu, PTRX, voice);

	u32 cpf = snd_emu10k1_ptr_read(emu, CPF, voice);

	snd_emu10k1_ptr_write_multiple(emu, voice,

		PTRX, (ptrx & ~PTRX_PITCHTARGET_MASK) | pitch_target,

		CPF, (cpf & ~(CPF_CURRENTPITCH_MASK | CPF_FRACADDRESS_MASK)) | pitch_target,

		REGLIST_END);

}



static void snd_emu10k1_playback_trigger_voice(struct snd_emu10k1 *emu,

					       struct snd_emu10k1_voice *evoice)

{
@@ -616,8 +627,7 @@ static void snd_emu10k1_playback_trigger_voice(struct snd_emu10k1 *emu, 
		pitch_target = PITCH_48000; /* Disable interpolators on emu1010 card */

	else 

		pitch_target = emu10k1_calc_pitch_target(runtime->rate);

	snd_emu10k1_ptr_write(emu, PTRX_PITCHTARGET, voice, pitch_target);

	snd_emu10k1_ptr_write(emu, CPF_CURRENTPITCH, voice, pitch_target);

	snd_emu10k1_playback_commit_pitch(emu, voice, pitch_target << 16);

}



static void snd_emu10k1_playback_stop_voice(struct snd_emu10k1 *emu,
@@ -626,8 +636,7 @@ static void snd_emu10k1_playback_stop_voice(struct snd_emu10k1 *emu, 
	unsigned int voice;



	voice = evoice->number;

	snd_emu10k1_ptr_write(emu, PTRX_PITCHTARGET, voice, 0);

	snd_emu10k1_ptr_write(emu, CPF_CURRENTPITCH, voice, 0);

	snd_emu10k1_playback_commit_pitch(emu, voice, 0);

}



static void snd_emu10k1_playback_set_running(struct snd_emu10k1 *emu,