On Wed, 31 Jul 2019 19:48:13 +0200, Paul Pawlowski wrote: > > Hello, > I have a device which clears the DMA buffer when I command it to start the > playback. How can this be workarounded? So it clears the DMA buffer at start, then you need to put the data on the DMA buffer again on the running stream? What a weird chip. > I found the SNDRV_PCM_INFO_DOUBLE flag, but it doesn't seem that it changes > alsa/alsa-lib behaviour. I wasn't able to find any drivers which shared > this quirk. > I'd like to avoid double buffering if possible, as once the stream is > actually started it's not required. The PCM_INFO_DOUBLE flag has no effect for anything like that. It's merely a information bit exposed to the user-space as a hint. In such a case, you need to implement some ugly workaround in the driver side. Since the double-buffer is needed only at start, you can save the whole content (up to appl_ptr) and write back after starting the stream. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
