Re: [PATCH v2] ARM: staging: bcm2835-audio: interpolate audio delay

2019-01-01 Thread Mike Brady
ote: > > On Sun, 11 Nov 2018 19:21:29 +0100, > Mike Brady wrote: >> >> /* hardware definition */ >> static const struct snd_pcm_hardware snd_bcm2835_playback_hw = { >> .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-11-11 Thread Mike Brady
> On 6 Nov 2018, at 21:31, Takashi Iwai wrote: > > On Tue, 06 Nov 2018 22:05:11 +0100, > Mike Brady wrote: >> >> >>> On 5 Nov 2018, at 16:11, Takashi Iwai wrote: >>> >>> On Mon, 05 Nov 2018 16:57:07 +0100, >>> Mike Brady wrote:

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-11-06 Thread Mike Brady
> On 5 Nov 2018, at 16:11, Takashi Iwai wrote: > > On Mon, 05 Nov 2018 16:57:07 +0100, > Mike Brady wrote: >> >>> One another thing I'd like to point out is that the value given in the >>> patch is nothing but an estimated position, optimistically calcu

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-11-05 Thread Mike Brady
Thanks for the comments and suggestions. > On 25 Oct 2018, at 08:37, Takashi Iwai wrote: > > Well, in the API POV, it's nothing wrong to keep hwptr sticking while > updating only delay value. It implies that the hardware chip doesn't > provide the hwptr update. As I understand it, this driver

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-10-28 Thread Mike Brady
> On 25 Oct 2018, at 08:37, Takashi Iwai wrote: > > On Thu, 25 Oct 2018 00:02:34 +0200, > Kirill Marinushkin wrote: >> When you play sound - the pointer increments. >>> >>> Unfortunately, when you play sound, the pointer does not actually >>> increment, for up to about 10 milliseconds.

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-10-28 Thread Mike Brady
Hi Kirill. Thanks for the post. Mike > On 25 Oct 2018, at 18:20, Kirill Marinushkin wrote: > > Hello Takashi, Mike, > > @Takashi > > On 10/25/18 09:37, Takashi Iwai wrote: >> Well, in the API POV, it's nothing wrong to keep hwptr sticking while >> updating only delay value. It implies that th

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-10-24 Thread Mike Brady
Hi Kirill. Thanks again for your comments. > On 24 Oct 2018, at 19:06, Kirill Marinushkin wrote: > > Hello Mike, > > On 10/24/18 10:20, Mike Brady wrote: >> Hi Kirill. Thanks for your comments. >> >>> On 22 Oct 2018, at 23:25, Kirill Marinushkin >

Re: [alsa-devel] [PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-10-24 Thread Mike Brady
mentioned above). All the best, Mike > FYI, there is >> a discussion of the effects of a downstream equivalent of this suggested >> patch >> at: >> https://github.com/raspberrypi/firmware/issues/1026#issuecomment-415746016. > > Thank you for the link, it clarifie

[PATCH v2] staging: bcm2835-audio: interpolate audio delay

2018-10-22 Thread Mike Brady
s -- 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 --- Changes in v2 -- remove inappropriate addition of SNDRV_PCM_INFO_BATCH flag .../vc0

Re: [PATCH] staging: bcm2835-audio: interpolate audio delay

2018-10-22 Thread Mike Brady
Hello Mike, > > On 10/18/18 12:57, Mike Brady wrote: > > + ktime_t now = ktime_get(); > > + > > + /* Give userspace better delay reporting by interpolating between GPU > > +* notifications, assuming audio speed is close enough to the clock > > +

[PATCH] staging: bcm2835-audio: interpolate audio delay

2018-10-18 Thread Mike Brady
s -- 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 --- .../vc04_services/bcm2835-audio/bcm2835-pcm.c | 23 ++- .../vc04_servic