All of lore.kernel.org
 help / color / mirror / Atom feed
From: Raymond Yau <superquad.vortex2@gmail.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: ALSA Development Mailing List <alsa-devel@alsa-project.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	clemens@ladisch.de, Tanu Kaskinen <tanu.kaskinen@linux.intel.com>,
	Arun Raghavan <arun@accosted.net>,
	David Henningsson <david.henningsson@canonical.com>
Subject: Re: PulseAudio and SNDRV_PCM_INFO_BATCH
Date: Sat, 20 Jun 2015 14:17:46 +0800	[thread overview]
Message-ID: <CAN8ccibjbE=-Z+3Vwb0YOktiFyOXLPXRpzrNfxArt3CQdwOmsA@mail.gmail.com> (raw)
In-Reply-To: <s5hmvzw9bn9.wl-tiwai@suse.de>

> > Hmm...I was trying to understand this power save argument. I tried to
> > figure out a "typical" URB size by just plugging my headset in, and I
> > saw wMaxPacketSize being 96 and/or 192 bytes.
> > Then, MAX_PACKS is set to either 6 (or 48 for USB 2.0 devices, but this
> > is just a headset).
> >
> > Can this be correct? Does it mean that we are getting interrupts every
> > 192 * 6 bytes (i e, every 6 ms for a 48kHz/stereo/16bit stream)?
>
> The driver can build up a URB containing multiple packets, so the
> wakeups can be reduced in some level.  But, then the hwptr update also
> suffers, and more badly, the in-flight size also increases -- both are
> bad for sample mixing, obviously.
>
>
>

Do it mean that period_bytes_max is wMaxPacketSize * MAX_PACKS, driver only
support small period sizes ?

  parent reply	other threads:[~2015-06-20  6:17 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-12 12:29 PulseAudio and SNDRV_PCM_INFO_BATCH Arun Raghavan
2015-06-12 12:32 ` Arun Raghavan
2015-06-12 13:43   ` Alexander E. Patrakov
2015-06-12 13:57     ` Alexander E. Patrakov
2015-06-17  3:04     ` Raymond Yau
2015-06-17  3:38       ` Alexander E. Patrakov
2015-06-15  3:42   ` Raymond Yau
2015-06-15  8:03 ` Lars-Peter Clausen
2015-06-15 11:39   ` Raymond Yau
2015-06-15 12:01     ` Lars-Peter Clausen
2015-06-15 13:34       ` Raymond Yau
2015-06-15 14:16         ` Lars-Peter Clausen
2015-06-16  2:33           ` Raymond Yau
2015-06-17  8:27             ` Lars-Peter Clausen
2015-06-17  9:19               ` Takashi Iwai
2015-06-17 15:09                 ` David Henningsson
2015-06-17 16:48                   ` Alexander E. Patrakov
2015-06-18  3:15                     ` Raymond Yau
2015-06-19 11:19                       ` Alexander E. Patrakov
2015-06-19  1:17                   ` Raymond Yau
2015-06-19 11:32                   ` Takashi Iwai
2015-06-20  3:24                     ` Raymond Yau
2015-06-20  6:17                     ` Raymond Yau [this message]
2015-06-22  2:35           ` Raymond Yau
2015-06-22  6:43             ` Lars-Peter Clausen
2015-06-22  7:49               ` Raymond Yau
2015-06-22  9:41               ` Clemens Ladisch
2015-06-22 11:54                 ` Raymond Yau
2015-06-22 12:10                   ` Alexander E. Patrakov
2015-06-22 12:34                     ` Raymond Yau
2015-06-22 12:49                       ` Alexander E. Patrakov
2015-06-22 15:50                         ` Raymond Yau
2015-06-22 16:28                           ` Alexander E. Patrakov
2015-06-24  5:51                             ` Raymond Yau
2015-06-22 22:52                     ` Takashi Sakamoto
2015-06-27 15:28   ` Alexander E. Patrakov
2015-06-27 17:15     ` Clemens Ladisch
2015-06-27 17:58       ` Alexander E. Patrakov
2015-06-28  2:09         ` Raymond Yau

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAN8ccibjbE=-Z+3Vwb0YOktiFyOXLPXRpzrNfxArt3CQdwOmsA@mail.gmail.com' \
    --to=superquad.vortex2@gmail.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=arun@accosted.net \
    --cc=clemens@ladisch.de \
    --cc=david.henningsson@canonical.com \
    --cc=lars@metafoo.de \
    --cc=tanu.kaskinen@linux.intel.com \
    --cc=tiwai@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.