Re: hdsp and midi problems

[Takashi Iwai <tiwai@suse.de>]

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At Mon, 23 Jun 2003 06:38:20 -0700,
Mark Knecht wrote:
> 
> >
> >
> > More information,
> >
> > when I run the program with 100% load using my VIA motherboard midi, I
> > loose no bytes as far as I can see.
> >
> > I use alsa 0.9.4
> >
> > Marcus
> 
> Marcus,
>    The HDSP 9652 MIDI interface has (for me under Linux) always dropped lots
> of notes. Mostly I find it interesting that it drops note off information
> and doesn't seem to drop note-on. I cannot be sure how well it handles
> controller information.

do you mean dropping notes in reading MIDI?
well, IIRC, you reported also that the behavior of MIDI out is
strange...  oh sigh.

> 
>    The same machine booted into Windows runs perfectly, so I'm pretty sure
> it's not a hardware issue.

dropping a note is surely a bug of the driver.
unless the FIFO overflows, no dropping should happen.

btw, could you try the attached patch?
(and in-advance-scheduled excuse if it causes a hang-up :)


Takashi

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Index: alsa-kernel/pci/rme9652/hdsp.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/pci/rme9652/hdsp.c,v
retrieving revision 1.34
diff -u -r1.34 hdsp.c
--- alsa-kernel/pci/rme9652/hdsp.c	18 Jun 2003 10:34:11 -0000	1.34
+++ alsa-kernel/pci/rme9652/hdsp.c	23 Jun 2003 14:04:20 -0000
@@ -1103,7 +1134,7 @@
 	int i;
 
 	spin_lock_irqsave (&hmidi->lock, flags);
-	if ((n_pending = snd_hdsp_midi_input_available (hmidi->hdsp, hmidi->id)) > 0) {
+	while ((n_pending = snd_hdsp_midi_input_available (hmidi->hdsp, hmidi->id)) > 0) {
 		if (hmidi->input) {
 			if (n_pending > (int)sizeof (buf)) {
 				n_pending = sizeof (buf);
@@ -1122,12 +1153,6 @@
 		}
 	}
 	hmidi->pending = 0;
-	if (hmidi->id) {
-		hmidi->hdsp->control_register |= HDSP_Midi1InterruptEnable;
-	} else {
-		hmidi->hdsp->control_register |= HDSP_Midi0InterruptEnable;
-	}
-	hdsp_write(hmidi->hdsp, HDSP_controlRegister, hmidi->hdsp->control_register);
 	spin_unlock_irqrestore (&hmidi->lock, flags);
 	return snd_hdsp_midi_output_write (hmidi);
 }
@@ -3155,35 +3157,38 @@
 
 	hdsp_write(hdsp, HDSP_interruptConfirmation, 0);
 
+	spin_lock (&hdsp->lock);
+
 	midi0status = hdsp_read (hdsp, HDSP_midiStatusIn0) & 0xff;
 	midi1status = hdsp_read (hdsp, HDSP_midiStatusIn1) & 0xff;
 	
 	if (audio) {
 		if (hdsp->capture_substream) {
+			spin_unlock (&hdsp->lock);
 			snd_pcm_period_elapsed(hdsp->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream);
+			spin_lock (&hdsp->lock);
 		}
 		
 		if (hdsp->playback_substream) {
+			spin_unlock (&hdsp->lock);
 			snd_pcm_period_elapsed(hdsp->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream);
+			spin_lock (&hdsp->lock);
 		}
 	}
 	
 	if (midi0 && midi0status) {
-		/* we disable interrupts for this input until processing is done */
-		hdsp->control_register &= ~HDSP_Midi0InterruptEnable;
-		hdsp_write(hdsp, HDSP_controlRegister, hdsp->control_register);
 		hdsp->midi[0].pending = 1;
 		schedule = 1;
 	}
 	if (midi1 && midi1status) {
-		/* we disable interrupts for this input until processing is done */
-		hdsp->control_register &= ~HDSP_Midi1InterruptEnable;
-		hdsp_write(hdsp, HDSP_controlRegister, hdsp->control_register);
 		hdsp->midi[1].pending = 1;
 		schedule = 1;
 	}
 	if (schedule)
-	    tasklet_hi_schedule(&hdsp->midi_tasklet);
+		tasklet_hi_schedule(&hdsp->midi_tasklet);
+
+	spin_unlock (&hdsp->lock);
+
 	return IRQ_HANDLED;
 }