At Mon, 3 Nov 2008 23:40:28 -0500, <brian-welch@xxxxxxx> wrote: > > Hello List, > > My first post, so excuse any ignorance. > > Is there a definitive/safe way to monitor ALSA's write pointer in the > dma_area? It seems like the ack callback and the appl_ptr is the > correct way, but I was told by another developer that appl_ptr doesn't > work in all cases. > > As a future optimization for my hardware, I may want to tell ALSA to use > a specific area of physical memory for it's dma_area, what is the best > way to do that? A good question. The ack callback is called only when the explicit read/write method is used. When mmap access is used, it won't be called. One hack would be to check appl_ptr in the pointer callback. This callback is called in snd_pcm_hwsync(), too. So, if you watch the appl_ptr change as frequently as possible, it'd be a good place for that. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
