I have a device here that can play PCM, but it's a weird implementation. Only 2 periods of 0x2000 words per buffer are supported, and there is no DMA - the driver must poll a status register, and when the chip is ready, deliver all 0x2000 words using outw() then send an end xfer command. I think I need to use an intermediate buffer, and implement copy/silence callbacks that write to this. Then I plan to use a tasklet or workqueue to do the actual xfer of PCM data to the hardware. A timer callback will periodically check whether at least 0x2000 words are in the buffer and if so, schedule the tasklet to drain it. I presume this implementation cannot support mmap() as there's no random access to the hardware buffer. Is this correct? Do I call snd_pcm_period_elapsed() from the timer, immediately before scheduling the tasklet, or from the tasklet, after the data has been transferred to the hw? In general, does this seem like a reasonable implementation? Lee ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
