> -----Original Message----- > From: Peter Zijlstra [mailto:pet...@infradead.org] > Sent: Friday, September 04, 2015 7:28 AM > To: Richard Cochran > Cc: Hall, Christopher S; Thomas Gleixner; Kirsher, Jeffrey T; > h...@zytor.com; mi...@redhat.com; john.stu...@linaro.org; x...@kernel.org; > linux-ker...@vger.kernel.org; netdev@vger.kernel.org; intel-wired- > l...@lists.osuosl.org > Subject: Re: [PATCH v3 1/4] Add correlated clocksource deriving system time > from an auxiliary clocksource > > > > (several milliseconds) and the result will be out of date by some > fraction of that > > > amount. > > > > Why does it take milliseconds to read one audio time stamp? > > So what I suspect, but please correct me if I'm wrong Chris, is that a > DSP will buffer and process audio signals, and only later wake up the > main CPU. > > So by the time the CPU is made aware of the data, it's 'old'.
That's about right. The DSP runs on a 1 ms cadence. Any access to registers controlled by the DSP will take 1-2 DSP ticks to access. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
