well, jaroslav's patch (to change the ESO value) was most of the
solution. in the diff below, i have also cleaned up the spurious
interrupt detection. with these two changes, i can run my trident with
a configuration that previously caused endless xruns in full duplex
mode (44.1kHz, 64 frame period) with no xruns at all.
jaroslav - if there are any parts of this patch you don't agree with,
send me back a modified one and i'll test it again.
i really hope that not all ALSA-supported h/w has issues like
this. the ability to function correctly in full duplex mode is
critical for all DAW software and much else besides.
--p
Index: trident.c
===================================================================
RCS file: /cvsroot/alsa/alsa-driver/lowlevel/pci/trident.c,v
retrieving revision 1.147
diff -c -u -p -r1.147 trident.c
--- trident.c 2001/05/11 14:21:02 1.147
+++ trident.c 2001/12/05 03:24:31
@@ -982,7 +982,14 @@ static int snd_trident_capture_prepare(s
// Set voice parameters
voice->CSO = 0;
- voice->ESO = (runtime->period_size * 2) - 1; /* in samples */
+
+ /* the +2 is a correction for a h/w problem. if not
+ used, the ESO interrupt is received before the capture pointer
+ has actually reached the ESO point. this causes errors in
+ the mid-level code.
+ */
+
+ voice->ESO = (runtime->period_size * 2) + 2 - 1; /* in samples */
voice->CTRL = snd_trident_control_mode(substream);
voice->FMC = 3;
voice->RVol = 0x7f;
@@ -3337,19 +3344,20 @@ static void snd_trident_interrupt(int ir
if ((chn_int & mask) == 0)
continue;
voice = &trident->synth.voices[channel];
- delta = (int)stimer - (int)voice->stimer;
- if (delta > -32 && delta < 32) {
- trident->spurious_irq_count++;
+
+ if (voice->pcm && voice->substream) {
+ delta = (int)(stimer - voice->stimer);
+ voice->stimer = stimer;
+
if (delta < 0)
delta = -delta;
- if (trident->spurious_irq_max_delta < delta)
- trident->spurious_irq_max_delta = delta;
- if (delta < -20 || delta > 20)
- snd_printk("spurious interrupt detected:
stimer = 0x%x, voice->stimer = 0x%x, delta = %i\n", stimer, voice->stimer, delta);
- continue;
- }
- voice->stimer = stimer;
- if (voice->pcm && voice->substream) {
+
+ if (delta < voice->substream->runtime->period_size -
+32) {
+ trident->spurious_irq_count++;
+ if (delta > trident->spurious_irq_max_delta)
+ trident->spurious_irq_max_delta =
+delta;
+ continue;
+ }
spin_unlock(&trident->reg_lock);
snd_pcm_period_elapsed(voice->substream);
spin_lock(&trident->reg_lock);
_______________________________________________
Alsa-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/alsa-devel
