Hi Mike, > Mike Brady <mikebrady@xxxxxxxxxx> hat am 11. November 2018 um 19:21 geschrieben: > > > When the BCM2835 audio output is used, userspace sees a jitter up to 10ms > in the audio position, aka "delay" -- the number of frames that must > be output before a new frame would be played. > Make this a bit nicer for userspace by interpolating the position > using the CPU clock. > The overhead is small -- an extra ktime_get() every time a GPU message > is sent -- and another call and a few calculations whenever the delay > is sought from userland. > At 48,000 frames per second, i.e. approximately 20 microseconds per > frame, it would take a clock inaccuracy of > 20 microseconds in 10 milliseconds -- 2,000 parts per million -- > to result in an inaccurate estimate, whereas > crystal- or resonator-based clocks typically have an > inaccuracy of 10s to 100s of parts per million. > > Signed-off-by: Mike Brady <mikebrady@xxxxxxxxxx> the former version of your patch has already been applied to staging-next. Didn't you received Greg's email? So please rebase your changes. Stefan _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
