Re: [PATCH] TEST of patch proposed for i810 audio

From: Nathan Bryant (nbryant@allegientsystems.com)
Date: Wed Dec 26 2001 - 18:37:08 EST


Nathan Bryant wrote:

>
> maybe this patch will solve your problem, samir, maybe it won't;
> regardless, it should fix at least one corner case and is either
> obviously correct or start_*c is not ;-)
>
> patch is against doug's 0.12.

[snip]

attached is a slightly more anal retentive version of my previous patch.
as in the previous patch, the goal is to make update_lvi completely
self-contained, ie resistant to changes in higher-level code, ie not
deadlock even if somebody really sets it up with bad state, also
eliminates one if/then/else thinko in 0.12 that could theoretically
cause dac to be started when you're trying to record, which would cause
a deadlock.


--- i810_audio.c.12 Wed Dec 19 02:04:06 2001
+++ linux/drivers/sound/i810_audio.c Wed Dec 26 18:22:37 2001
@@ -952,12 +952,16 @@
          * the CIV value to the next sg segment to be played so that when
          * we call start_{dac,adc}, things will operate properly
          */
- if (!dmabuf->enable && dmabuf->trigger) {
- if(rec && dmabuf->count != dmabuf->dmasize) {
+ if (!dmabuf->enable && dmabuf->ready) {
+ if(rec && dmabuf->count < dmabuf->dmasize &&
+ (dmabuf->trigger & PCM_ENABLE_INPUT))
+ {
                         outb((inb(port+OFF_CIV)+1)&31, port+OFF_LVI);
                         __start_adc(state);
                         while( !(inb(port + OFF_CR) & ((1<<4) | (1<<2))) ) ;
- } else if(dmabuf->count) {
+ } else if (!rec && dmabuf->count &&
+ (dmabuf->trigger & PCM_ENABLE_OUTPUT))
+ {
                         outb((inb(port+OFF_CIV)+1)&31, port+OFF_LVI);
                         __start_dac(state);
                         while( !(inb(port + OFF_CR) & ((1<<4) | (1<<2))) ) ;

-
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