From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 8B919DDEBD for ; Sat, 19 May 2007 10:14:05 +1000 (EST) Subject: Re: [PATCH 2.6.21-rt2] PowerPC: decrementer clockevent driver From: Benjamin Herrenschmidt To: Segher Boessenkool In-Reply-To: <51b3a75638604c9dd7ed60a10f0ed934@kernel.crashing.org> References: <200705172142.26739.sshtylyov@ru.mvista.com> <464CB071.5050504@ru.mvista.com> <9095839480a9686d9c40aa6143edb804@kernel.crashing.org> <464CB460.40905@ru.mvista.com> <97d47c2261fe9cd3f1a6c864278a6ab6@kernel.crashing.org> <1179464690.32247.370.camel@localhost.localdomain> <1179466769.3658.0.camel@localhost.localdomain> <1179472096.32247.394.camel@localhost.localdomain> <464DAD06.2060504@ru.mvista.com> <1179530872.32247.423.camel@localhost.localdomain> <51b3a75638604c9dd7ed60a10f0ed934@kernel.crashing.org> Content-Type: text/plain Date: Sat, 19 May 2007 10:13:16 +1000 Message-Id: <1179533596.32247.429.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Dave Liu , mingo@elte.hu, tglx@linutronix.de List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, 2007-05-19 at 01:49 +0200, Segher Boessenkool wrote: > > I find it extremely silly to implement it as edge anyway. The EE line > > is > > level triggered, and having a mix of edge and level on the same > > exception without a clean way to retrigger the DEC one other than > > waiting one tick is just causing trouble. > > It isn't edge triggered, it just automatically clears the > decrementer exception condition at its source when taken Which is exactly the same thing software-wise as edge triggered... Ben.