From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-02.arcor-online.net (mail-in-02.arcor-online.net [151.189.21.42]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.arcor.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 0553BDDDF7 for ; Fri, 18 May 2007 05:27:24 +1000 (EST) In-Reply-To: <200705172142.26739.sshtylyov@ru.mvista.com> References: <200705172142.26739.sshtylyov@ru.mvista.com> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: From: Segher Boessenkool Subject: Re: [PATCH 2.6.21-rt2] PowerPC: decrementer clockevent driver Date: Thu, 17 May 2007 21:27:17 +0200 To: Sergei Shtylyov Cc: linuxppc-dev@ozlabs.org, mingo@elte.hu, tglx@linutronix.de, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > + * We must write a positive value to the decrementer to clear > + * the interrupt on the IBM 970 CPU series. In periodic mode, > + * this happens when the decrementer gets reloaded later, but > + * in one-shot mode, we have to do it here since an event handler > + * may skip loading the new value... Nothing special about 970 here -- on *every* PowerPC, a decrementer exception exists as long as the high bit of the decrementer equals 1. BookE is different of course. Some other CPUs might deviate from the architecture as well. Segher