From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:57413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RujEI-0004mZ-4W for qemu-devel@nongnu.org; Tue, 07 Feb 2012 06:29:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RujE9-0007Ar-Dt for qemu-devel@nongnu.org; Tue, 07 Feb 2012 06:28:58 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:64033) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RujE8-0007An-Vh for qemu-devel@nongnu.org; Tue, 07 Feb 2012 06:28:49 -0500 From: Paul Brook Date: Tue, 7 Feb 2012 11:28:44 +0000 References: <11ee1a59f2bffdbdf37e49911df0428635cbb36f.1328594621.git.peter.crosthwaite@petalogix.com> In-Reply-To: <11ee1a59f2bffdbdf37e49911df0428635cbb36f.1328594621.git.peter.crosthwaite@petalogix.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Message-Id: <201202071128.45180.paul@codesourcery.com> Subject: Re: [Qemu-devel] [RFC PATCH v2 2/4] cadence_ttc: initial version of device model List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Peter A. G. Crosthwaite" Cc: peter.maydell@linaro.org, monstr@monstr.eu, edgar.iglesias@petalogix.com, qemu-devel@nongnu.org, John Linn , duyl@xilinx.com, linnj@xilinx.com, afaerber@suse.de, john.williams@petalogix.com > Implemented cadence Triple Timer Counter (TCC) It looks like you're implementing a periodic timer as sequence of chained oneshot timers. This is a bad idea. In qemu interrupt latency may be high, so you're likely to suffer from significant time skew. Paul