summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/sound/emu10k1.h38
-rw-r--r--sound/pci/emu10k1/emupcm.c67
2 files changed, 43 insertions, 62 deletions
diff --git a/include/sound/emu10k1.h b/include/sound/emu10k1.h
index 2d64f07e3883..ee662a1b0dc7 100644
--- a/include/sound/emu10k1.h
+++ b/include/sound/emu10k1.h
@@ -116,6 +116,10 @@
#define IPR_MIDITRANSBUFEMPTY 0x00000100 /* MIDI UART transmit buffer empty */
#define IPR_MIDIRECVBUFEMPTY 0x00000080 /* MIDI UART receive buffer empty */
#define IPR_CHANNELLOOP 0x00000040 /* Channel (half) loop interrupt(s) pending */
+ /* The interrupt is triggered shortly after */
+ /* CCR_READADDRESS has crossed the boundary; */
+ /* due to the cache, this runs ahead of the */
+ /* actual playback position. */
#define IPR_CHANNELNUMBERMASK 0x0000003f /* When IPR_CHANNELLOOP is set, indicates the */
/* highest set channel in CLIPL, CLIPH, HLIPL, */
/* or HLIPH. When IPR is written with CL set, */
@@ -586,24 +590,22 @@ SUB_REG(PEFE, FILTERAMOUNT, 0x000000ff) /* Filter envlope amount */
/* 0x1f: not used */
-#define CD0 0x20 /* Cache data 0 register */
-#define CD1 0x21 /* Cache data 1 register */
-#define CD2 0x22 /* Cache data 2 register */
-#define CD3 0x23 /* Cache data 3 register */
-#define CD4 0x24 /* Cache data 4 register */
-#define CD5 0x25 /* Cache data 5 register */
-#define CD6 0x26 /* Cache data 6 register */
-#define CD7 0x27 /* Cache data 7 register */
-#define CD8 0x28 /* Cache data 8 register */
-#define CD9 0x29 /* Cache data 9 register */
-#define CDA 0x2a /* Cache data A register */
-#define CDB 0x2b /* Cache data B register */
-#define CDC 0x2c /* Cache data C register */
-#define CDD 0x2d /* Cache data D register */
-#define CDE 0x2e /* Cache data E register */
-#define CDF 0x2f /* Cache data F register */
-
-/* 0x30-3f seem to be the same as 0x20-2f */
+// 32 cache registers (== 128 bytes) per channel follow.
+// In stereo mode, the two channels' caches are concatenated into one,
+// and hold the interleaved frames.
+// The cache holds 64 frames, so the upper half is not used in 8-bit mode.
+// All registers mentioned below count in frames.
+// The cache is a ring buffer; CCR_READADDRESS operates modulo 64.
+// The cache is filled from (CCCA_CURRADDR - CCR_CACHEINVALIDSIZE)
+// into (CCR_READADDRESS - CCR_CACHEINVALIDSIZE).
+// The engine has a fetch threshold of 32 bytes, so it tries to keep
+// CCR_CACHEINVALIDSIZE below 8 (16-bit stereo), 16 (16-bit mono,
+// 8-bit stereo), or 32 (8-bit mono). The actual transfers are pretty
+// unpredictable, especially if several voices are running.
+// Frames are consumed at CCR_READADDRESS, which is incremented afterwards,
+// along with CCCA_CURRADDR and CCR_CACHEINVALIDSIZE. This implies that the
+// actual playback position always lags CCCA_CURRADDR by exactly 64 frames.
+#define CD0 0x20 /* Cache data registers 0 .. 0x1f */
#define PTB 0x40 /* Page table base register */
#define PTB_MASK 0xfffff000 /* Physical address of the page table in host memory */
diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c
index a6c4f1895a08..feb575922738 100644
--- a/sound/pci/emu10k1/emupcm.c
+++ b/sound/pci/emu10k1/emupcm.c
@@ -112,6 +112,10 @@ static int snd_emu10k1_pcm_channel_alloc(struct snd_emu10k1_pcm * epcm, int voic
}
}
if (epcm->extra == NULL) {
+ // The hardware supports only (half-)loop interrupts, so to support an
+ // arbitrary number of periods per buffer, we use an extra voice with a
+ // period-sized loop as the interrupt source. Additionally, the interrupt
+ // timing of the hardware is "suboptimal" and needs some compensation.
err = snd_emu10k1_voice_alloc(epcm->emu,
epcm->type == PLAYBACK_EMUVOICE ? EMU10K1_PCM : EMU10K1_EFX,
1,
@@ -232,23 +236,6 @@ static unsigned int emu10k1_select_interprom(unsigned int pitch_target)
return CCCA_INTERPROM_2;
}
-/*
- * calculate cache invalidate size
- *
- * stereo: channel is stereo
- * w_16: using 16bit samples
- *
- * returns: cache invalidate size in samples
- */
-static inline int emu10k1_ccis(int stereo, int w_16)
-{
- if (w_16) {
- return stereo ? 24 : 26;
- } else {
- return stereo ? 24*2 : 26*2;
- }
-}
-
static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
int master, int extra,
struct snd_emu10k1_voice *evoice,
@@ -264,7 +251,6 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
unsigned char send_routing[8];
unsigned long flags;
unsigned int pitch_target;
- unsigned int ccis;
voice = evoice->number;
stereo = runtime->channels == 2;
@@ -284,10 +270,8 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
memcpy(send_amount, &mix->send_volume[tmp][0], 8);
}
- ccis = emu10k1_ccis(stereo, w_16);
-
if (master) {
- evoice->epcm->ccca_start_addr = start_addr + ccis;
+ evoice->epcm->ccca_start_addr = start_addr + 64 - 3;
}
if (stereo && !extra) {
// Not really necessary for the slave, but it doesn't hurt
@@ -317,11 +301,11 @@ static void snd_emu10k1_pcm_init_voice(struct snd_emu10k1 *emu,
else
pitch_target = emu10k1_calc_pitch_target(runtime->rate);
if (extra)
- snd_emu10k1_ptr_write(emu, CCCA, voice, start_addr |
+ 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 + ccis) |
+ snd_emu10k1_ptr_write(emu, CCCA, voice, (start_addr + 64 - 3) |
emu10k1_select_interprom(pitch_target) |
(w_16 ? 0 : CCCA_8BITSELECT));
/* Clear filter delay memory */
@@ -532,35 +516,30 @@ 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;
+ unsigned voice, stereo, 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;
- ccis = emu10k1_ccis(stereo, sample == 0);
- /* set cs to 2 * number of cache registers beside the invalidated */
- cs = (sample == 0) ? (32-ccis) : (64-ccis+1) >> 1;
- if (cs > 16) cs = 16;
- for (i = 0; i < cs; i++) {
+
+ // We assume that the cache is resting at this point (i.e.,
+ // CCR_CACHEINVALIDSIZE is very small).
+
+ // Clear leading frames. For simplicitly, this does too much,
+ // except for 16-bit stereo. And the interpolator will actually
+ // access them at all only when we're pitch-shifting.
+ for (int i = 0; i < 3; i++)
snd_emu10k1_ptr_write(emu, CD0 + i, voice, sample);
- if (stereo) {
- snd_emu10k1_ptr_write(emu, CD0 + i, voice + 1, sample);
- }
- }
- /* reset cache */
- snd_emu10k1_ptr_write(emu, CCR_CACHEINVALIDSIZE, voice, 0);
- snd_emu10k1_ptr_write(emu, CCR_READADDRESS, voice, cra);
- if (stereo) {
- snd_emu10k1_ptr_write(emu, CCR_CACHEINVALIDSIZE, voice + 1, 0);
- // The engine goes haywire if this one is out of sync
- snd_emu10k1_ptr_write(emu, CCR_READADDRESS, voice + 1, cra);
- }
- /* fill cache */
- snd_emu10k1_ptr_write(emu, CCR_CACHEINVALIDSIZE, voice, ccis);
+
+ // Fill cache
+ ccr = (64 - 3) << REG_SHIFT(CCR_CACHEINVALIDSIZE);
if (stereo) {
- snd_emu10k1_ptr_write(emu, CCR_CACHEINVALIDSIZE, voice+1, ccis);
+ // The engine goes haywire if CCR_READADDRESS is out of sync
+ snd_emu10k1_ptr_write(emu, CCR, voice + 1, ccr);
}
+ snd_emu10k1_ptr_write(emu, CCR, voice, ccr);
}
static void snd_emu10k1_playback_commit_volume(struct snd_emu10k1 *emu,
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-08-08 05:26:34 +0000