From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guillaume Clement Subject: [snd-usb-audio] frequent "delay: estimated xxx, actual yyy" messages Date: Sat, 21 Apr 2012 12:22:48 +0200 Message-ID: <3172169.OcqrdKakkS@siegfried> Reply-To: gclement@baobob.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) by alsa0.perex.cz (Postfix) with ESMTP id AF2BE248C9 for ; Sat, 21 Apr 2012 12:23:16 +0200 (CEST) Received: from siegfried.localnet (unknown [IPv6:2a01:e35:8b3b:6a90:224:1dff:fe73:2eb4]) (Authenticated sender: tortuxm@baobob.org) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id E26C0A809E for ; Sat, 21 Apr 2012 12:23:14 +0200 (CEST) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hello, I am using an USB soundcard (ID : 046d:0a24 : Logitech Speaker Lapdesk N550). During playback, I have frequent messages like these : delay: estimated 795, actual 662 delay: estimated 133, actual 0 delay: estimated 751, actual 662 delay: estimated 89, actual 0 When those messages appear, I am hearing some "cracks" from the soundcard. I've tried to make some research on this, I only found some messages that hint about some interrupt problems. I'm not using any closed source driver and I can reproduce the issue with any computer running Linux. On interesting thing to notice is that it happens only when the CPU is near idle. To workaround the problem, I can just do something like : nice -n 20 dd if=/dev/zero of=/dev/null bs=1k count=500G This would keep my CPU busy and I have no more messages nor cracks. This does not seem to be a recent regression since I've experienced this since I bought the lapdesk in december or so. I am still experiencing this issue with the latest rc (linux-3.4rc3 at the moment) I tried using different .asoundrc setups, tried to install pulseaudio (usually I'm using bare alsa) and still experience the problem. Below is some information that might help locating the problem. I can make some test if needed and even code if I have some information on where the problem might me located. Note: those commands are typed during playback. $ cat /proc/asound/N550/stream0 Logitech, Inc. Logitech Speaker Lapdesk N550 at usb-0000:00:1d.0-2, full speed : USB Audio Playback: Status: Running Interface = 1 Altset = 1 URBs = 2 [ 20 20 ] Packet Size = 200 Momentary freq = 44100 Hz (0x2c.199a) Interface 1 Altset 1 Format: S16_LE Channels: 2 Endpoint: 1 OUT (ADAPTIVE) Rates: 44100, 48000 $ cat /proc/asound/N550/pcm0p/info card: 0 device: 0 subdevice: 0 stream: PLAYBACK id: USB Audio name: USB Audio subname: subdevice #0 class: 0 subclass: 0 subdevices_count: 1 subdevices_avail: 0 $ cat /proc/asound/N550/pcm0p/sub0/hw_params access: RW_INTERLEAVED format: S16_LE subformat: STD channels: 2 rate: 44100 (44100/1) period_size: 5513 buffer_size: 22050 $ cat /proc/asound/N550/pcm0p/sub0/info card: 0 device: 0 subdevice: 0 stream: PLAYBACK id: USB Audio name: USB Audio subname: subdevice #0 class: 0 subclass: 0 subdevices_count: 1 subdevices_avail: 0 $ cat /proc/asound/N550/pcm0p/sub0/status state: RUNNING owner_pid : 1210 trigger_time: 3264.436419606 tstamp : 3302.883104696 delay : 20904 avail : 2646 avail_max : 21026 ----- hw_ptr : 1695160 appl_ptr : 1714564 $ cat /proc/asound/N550/pcm0p/sub0/sw_params tstamp_mode: NONE period_step: 1 avail_min: 5513 start_threshold: 16537 stop_threshold: 22050 silence_threshold: 0 silence_size: 0 boundary: 1445068800