Re: i810 audio patch

[Doug Ledford <dledford@redhat.com>]

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Nathan Bryant wrote:

> Nathan Bryant wrote:
> 
>> glquake.glx doesn't: "i810_audio: drain_dac, dma timeout?" 
> 
> 
> Turns out this has been broken for a while; stock 2.4.17pre1 has a 
> broken mmap too...
> 

Two questions:

1) This is a timeout on close.  Does it work up until then?

2) Does the attached patch (against the 0.08 driver) help?

-- 

  Doug Ledford <dledford@redhat.com>  http://people.redhat.com/dledford
       Please check my web site for aic7xxx updates/answers before
                       e-mailing me about problems

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--- i810_audio.c.08	Tue Dec  4 18:43:22 2001
+++ i810_audio.c.08b	Tue Dec  4 22:04:05 2001
@@ -664,26 +664,26 @@
 	return offset;
 }
 
-//static void resync_dma_ptrs(struct i810_state *state, int rec)
-//{
-//	struct dmabuf *dmabuf = &state->dmabuf;
-//	struct i810_channel *c;
-//	int offset;
-//
-//	if(rec) {
-//		c = dmabuf->read_channel;
-//	} else {
-//		c = dmabuf->write_channel;
-//	}
-//	if(c==NULL)
-//		return;
-//	offset = inb(state->card->iobase+c->port+OFF_CIV);
-//	if(offset == inb(state->card->iobase+c->port+OFF_LVI))
-//		offset++;
-//	offset *= dmabuf->fragsize;
-//	
-//	dmabuf->hwptr=dmabuf->swptr = offset;
-//}
+static void resync_dma_ptrs(struct i810_state *state, int rec)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	struct i810_channel *c;
+	int offset;
+
+	if(rec) {
+		c = dmabuf->read_channel;
+	} else {
+		c = dmabuf->write_channel;
+	}
+	if(c==NULL)
+		return;
+	offset = inb(state->card->iobase+c->port+OFF_CIV);
+	if(offset == inb(state->card->iobase+c->port+OFF_LVI))
+		offset++;
+	offset *= dmabuf->fragsize;
+	
+	dmabuf->hwptr=dmabuf->swptr = offset;
+}
 	
 /* Stop recording (lock held) */
 static inline void __stop_adc(struct i810_state *state)
@@ -1094,13 +1094,13 @@
 	return(avail);
 }
 
-static int drain_dac(struct i810_state *state, int nonblock)
+static int drain_dac(struct i810_state *state)
 {
 	DECLARE_WAITQUEUE(wait, current);
 	struct dmabuf *dmabuf = &state->dmabuf;
 	unsigned long flags;
 	unsigned long tmo;
-	int count;
+	int count, timeout=0;
 
 	if (!dmabuf->ready)
 		return 0;
@@ -1119,30 +1119,29 @@
 		if (count <= 0)
 			break;
 
-		if (signal_pending(current))
-			break;
-
-		i810_update_lvi(state,0);
 		if (dmabuf->enable != DAC_RUNNING)
 			start_dac(state);
 
-		if (nonblock) {
-			remove_wait_queue(&dmabuf->wait, &wait);
-			set_current_state(TASK_RUNNING);
-			return -EBUSY;
-		}
+		if (signal_pending(current))
+			break;
 
-		tmo = (dmabuf->dmasize * HZ) / dmabuf->rate;
-		tmo >>= 1;
+		/* set the timeout to exactly twice as long as it *should*
+		 * take for the DAC to drain the DMA buffer
+		 */
+		tmo = (count * HZ * 2) / dmabuf->rate;
 		if (!schedule_timeout(tmo ? tmo : 1) && tmo){
 			printk(KERN_ERR "i810_audio: drain_dac, dma timeout?\n");
+			timeout = 1;
 			break;
 		}
 	}
-	stop_dac(state);
-	synchronize_irq();
 	remove_wait_queue(&dmabuf->wait, &wait);
 	set_current_state(TASK_RUNNING);
+	if(count <= 0 || timeout) {
+		stop_dac(state);
+		synchronize_irq();
+		resync_dma_ptrs(state, 0 /* record channel */);
+	}
 	if (signal_pending(current))
 		return -ERESTARTSYS;
 
@@ -1651,7 +1650,7 @@
 #endif
 		if (dmabuf->enable != DAC_RUNNING || file->f_flags & O_NONBLOCK)
 			return 0;
-		drain_dac(state, 0);
+		drain_dac(state);
 		dmabuf->ready = 0;
 		dmabuf->swptr = dmabuf->hwptr = 0;
 		dmabuf->count = dmabuf->total_bytes = 0;
@@ -2324,7 +2323,7 @@
 	/* stop DMA state machine and free DMA buffers/channels */
 	if(dmabuf->enable & DAC_RUNNING ||
 	   (dmabuf->count && (dmabuf->trigger & PCM_ENABLE_OUTPUT))) {
-		drain_dac(state,0);
+		drain_dac(state);
 	}
 	if(dmabuf->enable & ADC_RUNNING) {
 		stop_adc(state);