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

Doug Ledford (dledford@redhat.com)
Thu, 27 Dec 2001 00:35:43 -0500


Nathan Bryant wrote:

> 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))) ) ;
>

This looks fine to me. I've added it to my 0.12 driver, bumped the number
to 0.13, put it up on my web site
(http://people.redhat.com/dledford/i810_audio.c.gz) and if that solves
people's problems then that's what I'll send to Marcello in a day or so.

Thanks Nathan, I've been to busy to look into it the last little bit :-(

-- 

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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