Re: [alsa-devel] [PATCH 6/6] ASoC/mpc5200: Add fudge factor to value reported by .pointer()
On Sat, Nov 07, 2009 at 01:34:55AM -0700, Grant Likely wrote: ALSA playback seems to be more reliable if the .pointer() hook reports a value slightly into the period, rather than right on the period boundary. This patch adds a fudge factor of 1/4 the period size to better estimate the actual position of the DMA engine in the audio buffer. It occurs to me that in terms of dealing with what's going on here this probably is achieving exactly the same effect as Jon's code in that it tells ALSA that things are a bit ahead of where the buffer started. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [alsa-devel] [PATCH 6/6] ASoC/mpc5200: Add fudge factor to value reported by .pointer()
On Sat, Nov 07, 2009 at 11:19:54AM -0700, Grant Likely wrote: On Sat, Nov 7, 2009 at 11:11 AM, Mark Brown It occurs to me that in terms of dealing with what's going on here this probably is achieving exactly the same effect as Jon's code in that it tells ALSA that things are a bit ahead of where the buffer started. Possibly, but I can both reproduce and eliminate the problem Jon is seeing regardless of whether or not this patch, so I'm not yet convinced. That doesn't entirely surprise me; I'm not convinced that the original approach entirely deals with the issue rather than just making it much harder to see. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [alsa-devel] [PATCH 6/6] ASoC/mpc5200: Add fudge factor to value reported by .pointer()
On Sat, Nov 7, 2009 at 12:33 PM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Sat, Nov 07, 2009 at 11:19:54AM -0700, Grant Likely wrote: On Sat, Nov 7, 2009 at 11:11 AM, Mark Brown It occurs to me that in terms of dealing with what's going on here this probably is achieving exactly the same effect as Jon's code in that it tells ALSA that things are a bit ahead of where the buffer started. Possibly, but I can both reproduce and eliminate the problem Jon is seeing regardless of whether or not this patch, so I'm not yet convinced. That doesn't entirely surprise me; I'm not convinced that the original approach entirely deals with the issue rather than just making it much harder to see. Indeed. I'm at the point where I'm far more interested in achieving correctness than trying to hobble together a set of conditions that appears to work most of the time. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
