This workaround fails to address the underlying problem, which is actually wholly self-made. Subsequent patches will fix it.

This reverts commit 56385a12d9bb9e173751f74b6c430742018cafc0.

Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- include/sound/emu10k1.h | 1 - sound/core/pcm_native.c | 4 ---- sound/pci/emu10k1/emu10k1.c | 4 ---- sound/pci/emu10k1/emupcm.c | 25 ++----------------------- sound/pci/emu10k1/memory.c | 4 +--- 5 files changed, 3 insertions(+), 35 deletions(-)

diff --git a/include/sound/emu10k1.h b/include/sound/emu10k1.h index 5ad2144fa530..2d64f07e3883 100644 --- a/include/sound/emu10k1.h +++ b/include/sound/emu10k1.h @@ -1670,7 +1670,6 @@ struct snd_emu10k1 { unsigned int address_mode; /* address mode */ unsigned long dma_mask; /* PCI DMA mask */ bool iommu_workaround; /* IOMMU workaround needed */ - unsigned int delay_pcm_irq; /* in samples */ int max_cache_pages; /* max memory size / PAGE_SIZE */ struct snd_dma_buffer silent_page; /* silent page */ struct snd_dma_buffer ptb_pages; /* page table pages */ diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 39a65d1415ab..95fc56e403b1 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1605,10 +1605,6 @@ static int snd_pcm_do_pause(struct snd_pcm_substream *substream, { if (substream->runtime->trigger_master != substream) return 0; - /* some drivers might use hw_ptr to recover from the pause - - update the hw_ptr now */ - if (pause_pushed(state)) - snd_pcm_update_hw_ptr(substream); /* The jiffies check in snd_pcm_update_hw_ptr*() is done by * a delta between the current jiffies, this gives a large enough * delta, effectively to skip the check once. diff --git a/sound/pci/emu10k1/emu10k1.c b/sound/pci/emu10k1/emu10k1.c index 0c97237af922..23adace1b969 100644 --- a/sound/pci/emu10k1/emu10k1.c +++ b/sound/pci/emu10k1/emu10k1.c @@ -34,7 +34,6 @@ static int max_synth_voices[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 64}; static int max_buffer_size[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 128}; static bool enable_ir[SNDRV_CARDS]; static uint subsystem[SNDRV_CARDS]; /* Force card subsystem model */ -static uint delay_pcm_irq[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};

module_param_array(index, int, NULL, 0444); MODULE_PARM_DESC(index, "Index value for the EMU10K1 soundcard."); @@ -56,8 +55,6 @@ module_param_array(enable_ir, bool, NULL, 0444); MODULE_PARM_DESC(enable_ir, "Enable IR."); module_param_array(subsystem, uint, NULL, 0444); MODULE_PARM_DESC(subsystem, "Force card subsystem model."); -module_param_array(delay_pcm_irq, uint, NULL, 0444); -MODULE_PARM_DESC(delay_pcm_irq, "Delay PCM interrupt by specified number of samples (default 0)."); /* * Class 0401: 1102:0008 (rev 00) Subsystem: 1102:1001 -> Audigy2 Value Model:SB0400 */ @@ -103,7 +100,6 @@ static int snd_card_emu10k1_probe(struct pci_dev *pci, enable_ir[dev], subsystem[dev]); if (err < 0) return err; - emu->delay_pcm_irq = delay_pcm_irq[dev] & 0x1f; err = snd_emu10k1_pcm(emu, 0); if (err < 0) return err; diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index 9f151a0a7756..27977d03e323 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -290,7 +290,7 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, evoice->epcm->ccca_start_addr = start_addr + ccis; if (extra) { start_addr += ccis; - end_addr += ccis + emu->delay_pcm_irq; + end_addr += ccis; } } if (stereo && !extra) { @@ -315,9 +315,7 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, snd_emu10k1_ptr_write(emu, PTRX, voice, (send_amount[0] << 8) | send_amount[1]); // Stereo slaves don't need to have the addresses set, but it doesn't hurt snd_emu10k1_ptr_write(emu, DSL, voice, end_addr | (send_amount[3] << 24)); - snd_emu10k1_ptr_write(emu, PSST, voice, - (start_addr + (extra ? emu->delay_pcm_irq : 0)) | - (send_amount[2] << 24)); + snd_emu10k1_ptr_write(emu, PSST, voice, start_addr | (send_amount[2] << 24)); if (emu->card_capabilities->emu_model) pitch_target = PITCH_48000; /* Disable interpolators on emu1010 card */ else @@ -647,23 +645,6 @@ static void snd_emu10k1_playback_set_stopped(struct snd_emu10k1 *emu, epcm->running = 0; }

-static inline void snd_emu10k1_playback_mangle_extra(struct snd_emu10k1 *emu, - struct snd_emu10k1_pcm *epcm, - struct snd_pcm_substream *substream, - struct snd_pcm_runtime *runtime) -{ - unsigned int ptr, period_pos; - - /* try to sychronize the current position for the interrupt - source voice */ - period_pos = runtime->status->hw_ptr - runtime->hw_ptr_interrupt; - period_pos %= runtime->period_size; - ptr = snd_emu10k1_ptr_read(emu, CCCA, epcm->extra->number); - ptr &= ~0x00ffffff; - ptr |= epcm->ccca_start_addr + period_pos; - snd_emu10k1_ptr_write(emu, CCCA, epcm->extra->number, ptr); -} - static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream, int cmd) { @@ -686,8 +667,6 @@ static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream, fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME: - if (cmd == SNDRV_PCM_TRIGGER_PAUSE_RELEASE) - snd_emu10k1_playback_mangle_extra(emu, epcm, substream, runtime); mix = &emu->pcm_mixer[substream->number]; snd_emu10k1_playback_unmute_voice(emu, epcm->voices[0], true, mix); snd_emu10k1_playback_unmute_voice(emu, epcm->voices[1], false, mix); diff --git a/sound/pci/emu10k1/memory.c b/sound/pci/emu10k1/memory.c index edb3f1763719..20b07117574b 100644 --- a/sound/pci/emu10k1/memory.c +++ b/sound/pci/emu10k1/memory.c @@ -315,10 +315,8 @@ snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *subst if (snd_BUG_ON(!hdr)) return NULL;

- idx = runtime->period_size >= runtime->buffer_size ? - (emu->delay_pcm_irq * 2) : 0; mutex_lock(&hdr->block_mutex); - blk = search_empty(emu, runtime->dma_bytes + idx); + blk = search_empty(emu, runtime->dma_bytes); if (blk == NULL) { mutex_unlock(&hdr->block_mutex); return NULL;

Given that the data is going to be ignored anyway, and that the cache does not influence interrupt timing (which is the purpose of the extra voices), it's pointless to pre-fill the cache.

Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- sound/pci/emu10k1/emupcm.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index 16e7d0ff97a4..a6c4f1895a08 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -528,14 +528,15 @@ static int snd_emu10k1_capture_prepare(struct snd_pcm_substream *substream) return 0; }

-static void snd_emu10k1_playback_invalidate_cache(struct snd_emu10k1 *emu, int extra, struct snd_emu10k1_voice *evoice) +static void snd_emu10k1_playback_invalidate_cache(struct snd_emu10k1 *emu, + struct snd_emu10k1_voice *evoice) { struct snd_pcm_runtime *runtime; unsigned int voice, stereo, i, ccis, cra = 64, cs, sample;

runtime = evoice->epcm->substream->runtime; voice = evoice->number; - stereo = (!extra && runtime->channels == 2); + stereo = (runtime->channels == 2); sample = snd_pcm_format_width(runtime->format) == 16 ? 0 : 0x80808080; ccis = emu10k1_ccis(stereo, sample == 0); /* set cs to 2 * number of cache registers beside the invalidated */ @@ -658,8 +659,7 @@ static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream, spin_lock(&emu->reg_lock); switch (cmd) { case SNDRV_PCM_TRIGGER_START: - snd_emu10k1_playback_invalidate_cache(emu, 1, epcm->extra); /* do we need this? */ - snd_emu10k1_playback_invalidate_cache(emu, 0, epcm->voices[0]); + snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[0]); fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME: @@ -803,9 +803,8 @@ static int snd_emu10k1_efx_playback_trigger(struct snd_pcm_substream *substream, case SNDRV_PCM_TRIGGER_START: /* prepare voices */ for (i = 0; i < NUM_EFX_PLAYBACK; i++) { - snd_emu10k1_playback_invalidate_cache(emu, 0, epcm->voices[i]); + snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[i]); } - snd_emu10k1_playback_invalidate_cache(emu, 1, epcm->extra); fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME:

The period_bytes_min parameter made no sense at all, as it didn't correlate with any hardware limitation. The same can be said of the buffer_bytes minimum constraint. Instead, apply a buffer_size constraint, which works on frames.

Sync up the constraints of the EFX playback with those of the regular playback, as there is no reason for them to diverge.

Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- sound/pci/emu10k1/emupcm.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index feb575922738..5226f0978408 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -457,9 +457,8 @@ static const struct snd_pcm_hardware snd_emu10k1_efx_playback = .rate_max = 48000, .channels_min = NUM_EFX_PLAYBACK, .channels_max = NUM_EFX_PLAYBACK, - .buffer_bytes_max = (64*1024), - .period_bytes_min = 64, - .period_bytes_max = (64*1024), + .buffer_bytes_max = (128*1024), + .period_bytes_max = (128*1024), .periods_min = 2, .periods_max = 2, .fifo_size = 0, @@ -851,7 +850,6 @@ static const struct snd_pcm_hardware snd_emu10k1_playback = .channels_min = 1, .channels_max = 2, .buffer_bytes_max = (128*1024), - .period_bytes_min = 64, .period_bytes_max = (128*1024), .periods_min = 1, .periods_max = 1024, @@ -956,25 +954,46 @@ static int snd_emu10k1_efx_playback_close(struct snd_pcm_substream *substream) return 0; }

+static int snd_emu10k1_playback_set_constraints(struct snd_pcm_runtime *runtime) +{ + int err; + + // The buffer size must be a multiple of the period size, to avoid a + // mismatch between the extra voice and the regular voices. + err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); + if (err < 0) + return err; + // The hardware is typically the cache's size of 64 frames ahead. + // Leave enough time for actually filling up the buffer. + err = snd_pcm_hw_constraint_minmax( + runtime, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 256, UINT_MAX); + return err; +} + static int snd_emu10k1_efx_playback_open(struct snd_pcm_substream *substream) { struct snd_emu10k1 *emu = snd_pcm_substream_chip(substream); struct snd_emu10k1_pcm *epcm; struct snd_emu10k1_pcm_mixer *mix; struct snd_pcm_runtime *runtime = substream->runtime; - int i, j; + int i, j, err;

epcm = kzalloc(sizeof(*epcm), GFP_KERNEL); if (epcm == NULL) return -ENOMEM; epcm->emu = emu; epcm->type = PLAYBACK_EFX; epcm->substream = substream; runtime->private_data = epcm; runtime->private_free = snd_emu10k1_pcm_free_substream; runtime->hw = snd_emu10k1_efx_playback; - + err = snd_emu10k1_playback_set_constraints(runtime); + if (err < 0) { + kfree(epcm); + return err; + } + for (i = 0; i < NUM_EFX_PLAYBACK; i++) { mix = &emu->efx_pcm_mixer[i]; for (j = 0; j < 8; j++) @@ -1005,12 +1024,7 @@ static int snd_emu10k1_playback_open(struct snd_pcm_substream *substream) runtime->private_data = epcm; runtime->private_free = snd_emu10k1_pcm_free_substream; runtime->hw = snd_emu10k1_playback; - err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); - if (err < 0) { - kfree(epcm); - return err; - } - err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX); + err = snd_emu10k1_playback_set_constraints(runtime); if (err < 0) { kfree(epcm); return err;

Originally, there was a 1:1 relationship between the PCM streams' and the low-level voices' parameters. The addition of multi-channel playback partially invalidated that, but didn't introduce proper layering, so things kept working only by virtue of the multi-channel device never having two channels (yet). The upcoming addition of 32-bit playback would complete upending the relationships.

So this patch detaches the low-level parameters from the high-level ones: we pass pre-calculated bit width and stereo flags to the low-level manipulation functions instead of calculating them in-place from the stream parameters.

Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- sound/pci/emu10k1/emupcm.c | 50 +++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 28 deletions(-)

diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index 5226f0978408..7924d185cf92 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -239,22 +239,21 @@ static unsigned int emu10k1_select_interprom(unsigned int pitch_target) static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, int master, int extra, struct snd_emu10k1_voice *evoice, + bool w_16, bool stereo, unsigned int start_addr, unsigned int end_addr, struct snd_emu10k1_pcm_mixer *mix) { struct snd_pcm_substream *substream = evoice->epcm->substream; struct snd_pcm_runtime *runtime = substream->runtime; unsigned int silent_page, tmp; - int voice, stereo, w_16; + int voice; unsigned char send_amount[8]; unsigned char send_routing[8]; unsigned long flags; unsigned int pitch_target;

voice = evoice->number; - stereo = runtime->channels == 2; - w_16 = snd_pcm_format_width(runtime->format) == 16;

spin_lock_irqsave(&emu->reg_lock, flags);

@@ -273,7 +272,7 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, if (master) { evoice->epcm->ccca_start_addr = start_addr + 64 - 3; } - if (stereo && !extra) { + if (stereo) { // Not really necessary for the slave, but it doesn't hurt snd_emu10k1_ptr_write(emu, CPF, voice, CPF_STEREO_MASK); } else { @@ -399,15 +398,15 @@ static int snd_emu10k1_playback_prepare(struct snd_pcm_substream *substream)

start_addr = epcm->start_addr >> w_16; end_addr = start_addr + runtime->period_size; - snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, + snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, w_16, false, start_addr, end_addr, NULL); start_addr >>= stereo; end_addr = start_addr + runtime->buffer_size; - snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], + snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], w_16, stereo, start_addr, end_addr, &emu->pcm_mixer[substream->number]); if (epcm->voices[1]) - snd_emu10k1_pcm_init_voice(emu, 0, 0, epcm->voices[1], + snd_emu10k1_pcm_init_voice(emu, 0, 0, epcm->voices[1], w_16, true, start_addr, end_addr, &emu->pcm_mixer[substream->number]); return 0; @@ -426,17 +425,17 @@ static int snd_emu10k1_efx_playback_prepare(struct snd_pcm_substream *substream)

channel_size = runtime->buffer_size;

- snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, + snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, true, false, start_addr, start_addr + (channel_size / 2), NULL);

/* only difference with the master voice is we use it for the pointer */ - snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], + snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], true, false, start_addr, start_addr + channel_size, &emu->efx_pcm_mixer[0]);

start_addr += channel_size; for (i = 1; i < NUM_EFX_PLAYBACK; i++) { - snd_emu10k1_pcm_init_voice(emu, 0, 0, epcm->voices[i], + snd_emu10k1_pcm_init_voice(emu, 0, 0, epcm->voices[i], true, false, start_addr, start_addr + channel_size, &emu->efx_pcm_mixer[i]); start_addr += channel_size; @@ -512,16 +511,14 @@ static int snd_emu10k1_capture_prepare(struct snd_pcm_substream *substream) }

static void snd_emu10k1_playback_invalidate_cache(struct snd_emu10k1 *emu, - struct snd_emu10k1_voice *evoice) + struct snd_emu10k1_voice *evoice, + bool w_16, bool stereo) { - struct snd_pcm_runtime *runtime; - unsigned voice, stereo, sample; + unsigned voice, sample; u32 ccr;

- runtime = evoice->epcm->substream->runtime; voice = evoice->number; - stereo = (runtime->channels == 2); - sample = snd_pcm_format_width(runtime->format) == 16 ? 0 : 0x80808080; + sample = w_16 ? 0 : 0x80808080;

// We assume that the cache is resting at this point (i.e., // CCR_CACHEINVALIDSIZE is very small). @@ -551,20 +548,15 @@ static void snd_emu10k1_playback_commit_volume(struct snd_emu10k1 *emu,

static void snd_emu10k1_playback_unmute_voice(struct snd_emu10k1 *emu, struct snd_emu10k1_voice *evoice, - bool master, + bool stereo, bool master, struct snd_emu10k1_pcm_mixer *mix) { - struct snd_pcm_substream *substream; - struct snd_pcm_runtime *runtime; unsigned int vattn; unsigned int tmp;

if (evoice == NULL) /* skip second voice for mono */ return; - substream = evoice->epcm->substream; - runtime = substream->runtime; - - tmp = runtime->channels == 2 ? (master ? 1 : 2) : 0; + tmp = stereo ? (master ? 1 : 2) : 0; vattn = mix->attn[tmp] << 16; snd_emu10k1_playback_commit_volume(emu, evoice, vattn); } @@ -627,23 +619,25 @@ static int snd_emu10k1_playback_trigger(struct snd_pcm_substream *substream, struct snd_pcm_runtime *runtime = substream->runtime; struct snd_emu10k1_pcm *epcm = runtime->private_data; struct snd_emu10k1_pcm_mixer *mix; + bool w_16 = snd_pcm_format_width(runtime->format) == 16; + bool stereo = runtime->channels == 2; int result = 0;

/* dev_dbg(emu->card->dev, "trigger - emu10k1 = 0x%x, cmd = %i, pointer = %i\n", (int)emu, cmd, substream->ops->pointer(substream)) */ spin_lock(&emu->reg_lock); switch (cmd) { case SNDRV_PCM_TRIGGER_START: - snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[0]); + snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[0], w_16, stereo); fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME: mix = &emu->pcm_mixer[substream->number]; - snd_emu10k1_playback_unmute_voice(emu, epcm->voices[0], true, mix); - snd_emu10k1_playback_unmute_voice(emu, epcm->voices[1], false, mix); + snd_emu10k1_playback_unmute_voice(emu, epcm->voices[0], stereo, true, mix); + snd_emu10k1_playback_unmute_voice(emu, epcm->voices[1], stereo, false, mix); snd_emu10k1_playback_set_running(emu, epcm); snd_emu10k1_playback_trigger_voice(emu, epcm->voices[0]); snd_emu10k1_playback_trigger_voice(emu, epcm->extra); @@ -781,13 +775,13 @@ static int snd_emu10k1_efx_playback_trigger(struct snd_pcm_substream *substream, case SNDRV_PCM_TRIGGER_START: /* prepare voices */ for (i = 0; i < NUM_EFX_PLAYBACK; i++) { - snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[i]); + snd_emu10k1_playback_invalidate_cache(emu, epcm->voices[i], true, false); } fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME: for (i = 0; i < NUM_EFX_PLAYBACK; i++) - snd_emu10k1_playback_unmute_voice(emu, epcm->voices[i], false, + snd_emu10k1_playback_unmute_voice(emu, epcm->voices[i], false, true, &emu->efx_pcm_mixer[i]);

snd_emu10k1_playback_set_running(emu, epcm);

Pull the special handling of extra voices out of snd_emu10k1_pcm_init_voice(), simplify snd_emu10k1_playback_pointer(), and make the logic overall clearer. Also, add verbose comments.

Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- sound/pci/emu10k1/emupcm.c | 81 ++++++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 29 deletions(-)

diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index 2af210961a87..0094f629ad47 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -269,9 +269,6 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, memcpy(send_amount, &mix->send_volume[tmp][0], 8); }

- if (master) { - evoice->epcm->ccca_start_addr = start_addr + 64 - 3; - } if (stereo) { // Not really necessary for the slave, but it doesn't hurt snd_emu10k1_ptr_write(emu, CPF, voice, CPF_STEREO_MASK); @@ -299,12 +296,7 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu, pitch_target = PITCH_48000; /* Disable interpolators on emu1010 card */ else pitch_target = emu10k1_calc_pitch_target(runtime->rate); - if (extra) - snd_emu10k1_ptr_write(emu, CCCA, voice, (end_addr - 3) | - emu10k1_select_interprom(pitch_target) | - (w_16 ? 0 : CCCA_8BITSELECT)); - else - snd_emu10k1_ptr_write(emu, CCCA, voice, (start_addr + 64 - 3) | + snd_emu10k1_ptr_write(emu, CCCA, voice, emu10k1_select_interprom(pitch_target) | (w_16 ? 0 : CCCA_8BITSELECT)); /* Clear filter delay memory */ @@ -401,6 +393,7 @@ static int snd_emu10k1_playback_prepare(struct snd_pcm_substream *substream) snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, w_16, false, start_addr, end_addr, NULL); start_addr >>= stereo; + epcm->ccca_start_addr = start_addr; end_addr = start_addr + runtime->buffer_size; snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], w_16, stereo, start_addr, end_addr, @@ -428,13 +421,8 @@ static int snd_emu10k1_efx_playback_prepare(struct snd_pcm_substream *substream) snd_emu10k1_pcm_init_voice(emu, 1, 1, epcm->extra, true, false, start_addr, start_addr + (channel_size / 2), NULL);

- /* only difference with the master voice is we use it for the pointer */ - snd_emu10k1_pcm_init_voice(emu, 1, 0, epcm->voices[0], true, false, - start_addr, start_addr + channel_size, - &emu->efx_pcm_mixer[0]); - - start_addr += channel_size; - for (i = 1; i < NUM_EFX_PLAYBACK; i++) { + epcm->ccca_start_addr = start_addr; + for (i = 0; i < NUM_EFX_PLAYBACK; i++) { snd_emu10k1_pcm_init_voice(emu, 0, 0, epcm->voices[i], true, false, start_addr, start_addr + channel_size, &emu->efx_pcm_mixer[i]); @@ -539,13 +527,45 @@ static void snd_emu10k1_playback_prepare_voices(struct snd_emu10k1 *emu, bool w_16, bool stereo, int channels) { + struct snd_pcm_substream *substream = epcm->substream; + struct snd_pcm_runtime *runtime = substream->runtime; + unsigned eloop_start = epcm->start_addr >> w_16; + unsigned loop_start = eloop_start >> stereo; + unsigned eloop_size = runtime->period_size; + unsigned loop_size = runtime->buffer_size; u32 sample = w_16 ? 0 : 0x80808080;

+ // To make the playback actually start at the 1st frame, + // we need to compensate for two circumstances: + // - The actual position is delayed by the cache size (64 frames) + // - The interpolator is centered around the 4th frame + loop_start += 64 - 3; for (int i = 0; i < channels; i++) { unsigned voice = epcm->voices[i]->number; + snd_emu10k1_ptr_write(emu, CCCA_CURRADDR, voice, loop_start); + loop_start += loop_size; snd_emu10k1_playback_fill_cache(emu, voice, sample, stereo); }

+ // The interrupt is triggered when CCCA_CURRADDR (CA) wraps around, + // which is ahead of the actual playback position, so the interrupt + // source needs to be delayed. + // + // In principle, this wouldn't need to be the cache's entire size - in + // practice, CCR_CACHEINVALIDSIZE (CIS) > `fetch threshold` has never + // been observed, and assuming 40 _bytes_ should be safe. + // + // The cache fills are somewhat random, which makes it impossible to + // align them with the interrupts. This makes a non-delayed interrupt + // source not practical, as the interrupt handler would have to wait + // for (CA - CIS) >= period_boundary for every channel in the stream. + // + // This is why all other (open) drivers for these chips use timer-based + // interrupts. + // + eloop_start += eloop_size - 3; + snd_emu10k1_ptr_write(emu, CCCA_CURRADDR, epcm->extra->number, eloop_start); + // It takes a moment until the cache fills complete, // but the unmuting takes long enough for that. } @@ -745,24 +765,27 @@ static snd_pcm_uframes_t snd_emu10k1_playback_pointer(struct snd_pcm_substream * struct snd_emu10k1 *emu = snd_pcm_substream_chip(substream); struct snd_pcm_runtime *runtime = substream->runtime; struct snd_emu10k1_pcm *epcm = runtime->private_data; - unsigned int ptr; + int ptr;

if (!epcm->running) return 0; + ptr = snd_emu10k1_ptr_read(emu, CCCA, epcm->voices[0]->number) & 0x00ffffff; -#if 0 /* Perex's code */ - ptr += runtime->buffer_size; ptr -= epcm->ccca_start_addr; - ptr %= runtime->buffer_size; -#else /* EMU10K1 Open Source code from Creative */ - if (ptr < epcm->ccca_start_addr) - ptr += runtime->buffer_size - epcm->ccca_start_addr; - else { - ptr -= epcm->ccca_start_addr; - if (ptr >= runtime->buffer_size) - ptr -= runtime->buffer_size; - } -#endif + + // This is the size of the whole cache minus the interpolator read-ahead, + // which leads us to the actual playback position. + // + // The cache is constantly kept mostly filled, so in principle we could + // return a more advanced position representing how far the hardware has + // already read the buffer, and set runtime->delay accordingly. However, + // this would be slightly different for every channel (and remarkably slow + // to obtain), so only a fixed worst-case value would be practical. + // + ptr -= 64 - 3; + if (ptr < 0) + ptr += runtime->buffer_size; + /* dev_dbg(emu->card->dev, "ptr = 0x%lx, buffer_size = 0x%lx, period_size = 0x%lx\n",