From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Missing exactly 3 of 8 audio packets? Date: Sun, 25 Nov 2012 17:39:02 +0100 Message-ID: <50B249A6.108@ladisch.de> References: <50AE99E7.6080008@gmail.com> <50B21255.8080202@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by alsa0.perex.cz (Postfix) with ESMTP id A23D1260202 for ; Sun, 25 Nov 2012 17:39:19 +0100 (CET) In-Reply-To: <50B21255.8080202@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Daniel Mack Cc: Daniel Griscom , Alsa Developer List-Id: alsa-devel@alsa-project.org Daniel Mack wrote: >> On 21.11.2012 21:13, Daniel Griscom wrote: >>> 1) Once in a while (every few seconds or minutes) a single >>> packet will be missed >>> >>> 2) Once in a longer while (every few minutes or hours), the >>> system will go into a continuing error condition where three of >>> every eight packets are missed. > [...] > This test will tell us whether data is in fact lost before it hits the > usb audio driver, or if it's dropped by the USB HCD. These look like hardware errors. You might want to try to check the frames' status in retire_playback_urb(), but this will show only DMA/ FIFO problems on the host; the HC will not be able to detect whether the receiving device has handled the packet. Regards, Clemens