From: Clemens Ladisch <clemens@ladisch.de>
To: "Alexander E. Patrakov" <patrakov@gmail.com>,
ALSA Development Mailing List <alsa-devel@alsa-project.org>,
Takashi Iwai <tiwai@suse.de>,
David Henningsson <david.henningsson@canonical.com>,
Takashi Sakamoto <o-takashi@sakamocchi.jp>
Subject: Re: Master Plan on rewinding
Date: Tue, 09 Sep 2014 10:43:06 +0200 [thread overview]
Message-ID: <540EBD9A.9000009@ladisch.de> (raw)
In-Reply-To: <540D5B46.3020904@gmail.com>
Alexander E. Patrakov wrote:
> |---------|---------P----h----p---------|-a-------|---------|
>
> So, what should alsa-lib return for snd_pcm_avail() and snd_pcm_rewind()?
> The driver only knows that "P" is already used, can infer that "p" isn't
> used yet, and knows nothing about samples in the middle.
Indeed. However, the DMA pointer moves asynchronously, so it is possible
that it has already moved beyond p when snd_pcm_rewindable() returns.
For the samples between P and p, the risk is larger than for those after
p, but p is not a boundary where the risk abruptly decreases.
It would make sense to report the pointer update granularity, but not
to adjust the return value of snd_pcm_avail/rewindable().
Regards,
Clemens
next prev parent reply other threads:[~2014-09-09 8:43 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-07 15:16 Master Plan on rewinding Alexander E. Patrakov
2014-09-07 18:38 ` Tanu Kaskinen
2014-09-07 19:05 ` Alexander E. Patrakov
2014-09-07 20:51 ` Clemens Ladisch
2014-09-08 3:06 ` Raymond Yau
2014-09-08 7:31 ` Alexander E. Patrakov
2014-09-09 8:43 ` Clemens Ladisch [this message]
2014-09-09 8:55 ` Alexander E. Patrakov
2014-09-09 9:08 ` David Henningsson
2014-09-09 9:31 ` Alexander E. Patrakov
2014-09-21 2:02 ` Raymond Yau
2014-09-22 13:20 ` Lars-Peter Clausen
2014-09-22 13:36 ` Alexander E. Patrakov
2014-09-22 13:44 ` Lars-Peter Clausen
2014-09-23 8:29 ` Raymond Yau
2014-09-23 10:22 ` Alexander E. Patrakov
2014-09-09 13:45 ` Clemens Ladisch
2014-09-09 15:55 ` Alexander E. Patrakov
2014-09-09 16:09 ` Takashi Iwai
2014-09-07 23:12 ` David Henningsson
2014-09-09 19:56 ` Pierre-Louis Bossart
2014-09-10 5:38 ` Alexander E. Patrakov
2014-09-08 7:34 ` Lars-Peter Clausen
2014-09-08 7:59 ` David Henningsson
2014-09-08 8:46 ` Alexander E. Patrakov
2014-09-08 9:26 ` David Henningsson
2014-09-08 10:21 ` Alexander E. Patrakov
2014-09-09 8:43 ` Clemens Ladisch
2014-09-11 3:49 ` Raymond Yau
2014-09-11 4:19 ` A. C. Censi
2014-09-13 9:15 ` Raymond Yau
2014-09-11 5:28 ` Alexander E. Patrakov
2014-09-11 6:21 ` Raymond Yau
2014-09-13 8:57 ` Raymond Yau
2014-09-13 10:43 ` Alexander E. Patrakov
2014-09-13 11:33 ` Raymond Yau
2014-09-13 11:36 ` Alexander E. Patrakov
2014-09-13 18:35 ` Alexander E. Patrakov
2014-09-14 11:37 ` Raymond Yau
2014-09-14 12:07 ` Alexander E. Patrakov
2014-09-15 2:43 ` Raymond Yau
2014-09-15 9:19 ` Takashi Iwai
2014-09-15 9:58 ` Alexander E. Patrakov
2014-09-15 10:08 ` Takashi Iwai
2014-09-15 17:01 ` Pierre-Louis Bossart
2014-09-15 17:14 ` Alexander E. Patrakov
2014-09-15 18:08 ` Takashi Iwai
2014-09-18 1:15 ` Raymond Yau
2014-09-21 9:22 ` Alexander E. Patrakov
2014-09-21 9:53 ` Clemens Ladisch
2014-09-21 10:56 ` Alexander E. Patrakov
2014-09-22 3:27 ` Raymond Yau
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