Hello, > > anyway, above patch might have fixed the issue and I was able to do some > > measurements on a beagleboard (ARMv7, OMAP3, TPS65950 PMIC audio), > > Linux kernel 3.7 and PA shortly before the srbchannel patches... > > Even the driver use SNDRV_PCM_INFO_NO_PERIOD_WAKEUP which is necessary but > no sufficient > > For timer schedulling, the driver need to report dma residue > and it look like some omap cannot report DMA residue granularity > > Can your hardware report dma residue granularity? > > https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc/omap/omap-pcm.c > > static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream > *substream) > { > snd_pcm_uframes_t offset; > > if (pcm_omap1510()) this is true for ancient OMAP1 only, OMAP3 uses snd_dmaengine_pcm_pointer() > offset = snd_dmaengine_pcm_pointer_no_residue(substream); > else > offset = snd_dmaengine_pcm_pointer(substream); > > return offset; > } > https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/soc/soc-generic-dmaengine-pcm.c?id=93b943edfc5e439f7b843535e0bb0f7d2371f67f > https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/soc/soc-generic-dmaengine-pcm.c?id=478028e088d6a94666d8a776be2cd2291faf3bbd these are rather recent additions, I'm using kernel 3.7 (could try a newer of course) p. -- Peter Meerwald +43-664-2444418 (mobile)
