From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=39372 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OMggY-0006SR-Q8 for qemu-devel@nongnu.org; Thu, 10 Jun 2010 08:16:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OMggX-0004cf-GY for qemu-devel@nongnu.org; Thu, 10 Jun 2010 08:16:38 -0400 Received: from mail.codesourcery.com ([38.113.113.100]:52380) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMggX-0004cM-6r for qemu-devel@nongnu.org; Thu, 10 Jun 2010 08:16:37 -0400 From: Paul Brook Subject: Re: [Qemu-devel] Disable PS/2 mouse Date: Thu, 10 Jun 2010 13:15:31 +0100 References: <4C0E3C75.7070209@dlh.net> <4C109048.9060007@redhat.com> <4C10952B.6090202@redhat.com> In-Reply-To: <4C10952B.6090202@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201006101315.33801.paul@codesourcery.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Lieven , dlaor@redhat.com, Gerd Hoffmann , Markus Armbruster > For usb hid devices: No idea how they work and whenever we can put them > into sleep somehow (with/without guest cooperation). The issue with USB is that it is (by design) a polled system. The UHCI adapter has to wakeup every 1ms to read transfer descriptors from guest RAM. Until recently there was a bug in the UHCI emulation that would wake the guest even if the tablet NACKed the poll. See http://lists.nongnu.org/archive/html/qemu-devel/2010-04/msg00150.html USB does support "autosuspend". This allows a guest to put a device to sleep, and have it wake up when something interesting happens. In theory this includes HID devices. However I believe linux disables it because there's so much broken hardware out there that implements it incorrectly. I suspect qemu does not currently implement this feature either. Paul