From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NxQXv-00075D-S7 for qemu-devel@nongnu.org; Thu, 01 Apr 2010 15:59:19 -0400 Received: from [140.186.70.92] (port=37515 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NxQXu-00073l-I2 for qemu-devel@nongnu.org; Thu, 01 Apr 2010 15:59:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1NxQXt-0001z6-5M for qemu-devel@nongnu.org; Thu, 01 Apr 2010 15:59:18 -0400 Received: from mail-pz0-f180.google.com ([209.85.222.180]:40162) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NxQXt-0001yg-0n for qemu-devel@nongnu.org; Thu, 01 Apr 2010 15:59:17 -0400 Received: by pzk10 with SMTP id 10so1497068pzk.28 for ; Thu, 01 Apr 2010 12:59:15 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 1 Apr 2010 22:59:15 +0300 Message-ID: From: Blue Swirl Content-Type: text/plain; charset=UTF-8 Subject: [Qemu-devel] Re: 452efb didn't show up in the list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Artyom Tarasenko Cc: qemu-devel Which list? On 4/1/10, Artyom Tarasenko wrote: > and looks wrong or incomplete to me: > > >According to Sun4M System Architecture Manual chapter 5.3.2, a limit > >of 0 will not generate interrupts. > > This is indeed correct, but the chapter 5.3.2 also explains why: > > "Setting the limit register to 0 allows the counter to free run. Since the > timer always resets to a value of 500 nS after reaching maximum count, > there is no match and no interrupts are generated." > > The part about 500 nS (0x00000200 in the counter register) and > no match seems to be not addressed. The 500ns offset part could be addressed by making the timer period shorter by 1 tick. I doubt such a change would have any visible difference with QEMU, except that tick count of 0 should never appear in the counter but it may now. For the no match part, t->reached should not be set if t->limit == 0.