Re: [Openvortex-dev] Re: [Alsa-devel] au8830+via & alsa 0.9.7c

[Wilfried Weissmann]

Manuel Jander wrote:
> Hallo Wilfried,
>
> If you change the maximal fragment count to 4, instead of "no limit"
> setting 0x7fff, then it works.
>
> that is, change:
>
>    int arg = 0x7FFF000B;
>
> into: 
>
>    int arg = 0x0004000B;

it only works if you use exactly 4x "soundplay(BUFFERSIZE(beep), beep)". 
and i think the reason is that the dma engine needs to be setup after 
resuming. like putting a vortex_adbdma_setbuffers() in 
snd_vortex_pcm_trigger(). however the starting offset is not 0 but 
wherever the playback stopped.
so far i have simply put in the SNDDRV_PCM_TRIGGER_START branch of the 
vortex trigger callback the following 2 lines:

vortex_adbdma_setstartbuffer(chip, dma,
            (((vortex_t *) chip)->dma_adb[dma].period_real+1)&3);

then i could hear the "silence" and the "beep" sound from the example 
code. but ofcourse only the first period of the sample.

if i have some spare time then i will investigate this problem further 
next week.

> Any fragment count value larger than 4 causes trouble. THe aureal vortex
> has a 4 hardware Scatter Gather table (used in a linear buffer fashion),
> which is extended to upto 64 virtual pages.
>
> If i discover something else, i let you now.
>
> Best Regards
>
> Manuel

Greetings,
Wilfried