From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:61000) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VepHM-0002Mo-Mu for qemu-devel@nongnu.org; Fri, 08 Nov 2013 11:51:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VepHF-0007Yl-Ch for qemu-devel@nongnu.org; Fri, 08 Nov 2013 11:51:28 -0500 Received: from david.siemens.de ([192.35.17.14]:34839) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VepHF-0007Xc-2z for qemu-devel@nongnu.org; Fri, 08 Nov 2013 11:51:21 -0500 Message-ID: <527D1685.8020503@siemens.com> Date: Fri, 08 Nov 2013 17:51:17 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <1379583298-7524-1-git-send-email-kraxel@redhat.com> <1379583298-7524-2-git-send-email-kraxel@redhat.com> <524C1C42.8050502@siemens.com> <1381130180.13574.13.camel@nilsson.home.kraxel.org> <52553638.7000801@siemens.com> <1381318925.12583.82.camel@nilsson.home.kraxel.org> <527CEE60.5020109@siemens.com> <1383925171.4350.3.camel@nilsson.home.kraxel.org> In-Reply-To: <1383925171.4350.3.camel@nilsson.home.kraxel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/7] usb: remove old usb-host code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: qemu-devel@nongnu.org On 2013-11-08 16:39, Gerd Hoffmann wrote: > Hi, > >> OK, then here is the first issue I ran into while trying libusbx (git >> head, i.e. 1.0.17+: The new stack causes significant latency issues that >> makes it almost unusable for pass-through of USB audio devices (some >> headset in my case). Reverting usb-linux and disabling libusb over QEMU >> git head makes things work again. I'll have to stick with this for now >> as it is affecting my work environment. >> >> Any spontaneous ideas how to analyse or even resolve this? > > Try setting isobsize property to something smaller than 32 (which is the > default). OK, isobsize=2 and isobufs=32 helped, possibly other combinations as well - but not just reducing isobsize or increasing isobufs. Any theory about this? How can we find better defaults? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux