Re: i810 audio patch

[Nathan Bryant <nbryant@optonline.net>]

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Umm, duh, here's the actual patch. :-)

Nathan Bryant wrote:

> Doug Ledford wrote:
>
>> The attached patch should get me the debugging output I need to solve 
>> the problem.  If you'll get me the output, then I can likely have a 
>> working version in short order.
>
>
> Here is a fix. It is diffed against your original 0.08 version, Doug.
>
> It makes GETOPTR set the LVI to the hardware fragment preceding the 
> one that's currently playing. In the case of Quake, that means Quake 
> must call GETOPTR at least every 3/4ths of a DMA buffer. Hopefully 
> that requirement should be relaxed enough. The alternate fix is to 
> modify the completion handlers.
>
> I don't see anything obvious in the databook about how to make the 
> hardware loop infinitely without taking any additional input from us.
>
> Comments, please.
>



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--- i810_audio.c.08	Tue Dec  4 19:43:21 2001
+++ linux/drivers/sound/i810_audio.c	Wed Dec  5 14:52:28 2001
@@ -197,7 +197,7 @@
 #define INT_MASK (INT_SEC|INT_PRI|INT_MC|INT_PO|INT_PI|INT_MO|INT_NI|INT_GPI)
 
 
-#define DRIVER_VERSION "0.07"
+#define DRIVER_VERSION "0.08n"
 
 /* magic numbers to protect our data structures */
 #define I810_CARD_MAGIC		0x5072696E /* "Prin" */
@@ -1651,7 +1651,10 @@
 #endif
 		if (dmabuf->enable != DAC_RUNNING || file->f_flags & O_NONBLOCK)
 			return 0;
-		drain_dac(state, 0);
+		if (!dmabuf->mapped)
+			drain_dac(state, 0);
+		else
+			stop_dac(state);
 		dmabuf->ready = 0;
 		dmabuf->swptr = dmabuf->hwptr = 0;
 		dmabuf->count = dmabuf->total_bytes = 0;
@@ -1913,16 +1916,31 @@
 		if (!dmabuf->ready && (val = prog_dmabuf(state, 0)) != 0)
 			return val;
 		spin_lock_irqsave(&state->card->lock, flags);
-		val = i810_get_free_write_space(state);
+		i810_update_ptr(state);
 		cinfo.bytes = dmabuf->total_bytes;
 		cinfo.ptr = dmabuf->hwptr;
-		cinfo.blocks = val/dmabuf->userfragsize;
+		/* blocks is only valid in mmap mode, according to API doc */
+		cinfo.blocks = 0;
 		if (dmabuf->mapped && (dmabuf->trigger & PCM_ENABLE_OUTPUT)) {
-			dmabuf->count += val;
-			dmabuf->swptr = (dmabuf->swptr + val) % dmabuf->dmasize;
+			/* blocks is supposed to reset to 0 on every call to GETOPTR */
+			/* hopefully nobody else destroys count so we can use it for this purpose
+			   in mmap mode */
+			cinfo.blocks = (dmabuf->dmasize - dmabuf->count - dmabuf->fragsize) /
+				dmabuf->userfragsize;
+			dmabuf->count = dmabuf->dmasize - dmabuf->fragsize;
+			dmabuf->swptr = (dmabuf->dmasize + dmabuf->hwptr - dmabuf->fragsize) 
+				% dmabuf->dmasize;
+#ifdef DEBUG
+			printk("SNDCTL_DSP_GETOPTR: calling __i810_update_lvi for swptr %d\n",
+				dmabuf->swptr);
+#endif
 			__i810_update_lvi(state, 0);
-			if (!dmabuf->enable)
+			if (!dmabuf->enable) {
+#ifdef DEBUG
+				printk("SNDCTL_DSP_GETOPTR: calling __start_dac\n");
+#endif
 				__start_dac(state);
+			}
 		}
 		spin_unlock_irqrestore(&state->card->lock, flags);
 #ifdef DEBUG
@@ -2324,7 +2342,12 @@
 	/* 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);
+		if (!dmabuf->mapped)
+			drain_dac(state,0);
+		else {
+			stop_dac(state);
+			synchronize_irq();
+		}
 	}
 	if(dmabuf->enable & ADC_RUNNING) {
 		stop_adc(state);