Takashi Iwai wrote: > At Tue, 01 Aug 2006 21:14:24 +0100, > Julien Bramary wrote: > >> Lee Revell wrote: >> >> >>>> > "PCM engine" refers to the hardware's PCM engine, not ALSA's. It's 100% >>>> > device dependent - you need to consult the docs for your sound device to >>>> > determine how to start the PCM. >>>> > >>>> > Lee >>>> >> Thanks, I see now why it starts, I'm doing some inits in my dac in the >> open callback... I should do those here in the trigger. >> > > Remember that the trigger callback is designed really as a "trigger". > That is, it should be executed as shortly as possible. The callback > is even in the atomic context within spinlock and irq disablement, so > any function that my sleep shall cause lockup. > > If you need to allocate something, it should be done in either > open, hw_params or prepare callback. Only start and stop are done in > trigger callback. > > > Takashi > > Thanks for the reminder. I think this should be ok. The only function I now have in the trigger is the following 'write' (atomic enough): /* enable SSC data Tx */ at91_ssc_write(AT91_SSC_CR, AT91_SSC_TXEN); Cheers, Julien ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
