Re: i810 audio patch

Nathan Bryant (nbryant@optonline.net)
Wed, 05 Dec 2001 15:05:15 -0500


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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);

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