From owner-freebsd-alpha Fri Nov 17 9: 5:54 2000 Delivered-To: freebsd-alpha@freebsd.org Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (Postfix) with ESMTP id 96EFD37B479; Fri, 17 Nov 2000 09:05:52 -0800 (PST) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.9.3/8.9.3) with ESMTP id MAA12231; Fri, 17 Nov 2000 12:05:48 -0500 (EST) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.11.1/8.9.1) id eAHH5mx49949; Fri, 17 Nov 2000 12:05:48 -0500 (EST) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Fri, 17 Nov 2000 12:05:47 -0500 (EST) To: Bernd Walter Cc: John Baldwin , Christian Weisgerber , freebsd-alpha@FreeBSD.org Subject: Re: PC164 IDE only works (was: SMPng stability) In-Reply-To: <20001116221125.A12204@cicely8.cicely.de> References: <20001116212040.A12094@cicely8.cicely.de> <20001116221125.A12204@cicely8.cicely.de> X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid Message-ID: <14869.25705.810908.875060@grasshopper.cs.duke.edu> Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org An interesting comment found in the linux kernel sources: /* In theory, the PC164 has the same interrupt hardware as the other Cabriolet based systems. However, something got screwed up late in the development cycle which broke the interrupt masking hardware. Repeat, it is not possible to mask and ack interrupts. At all. In an attempt to work around this, while processing interrupts, we do not allow the IPL to drop below what it is currently. This prevents the possibility of recursion. ??? Another option might be to force all PCI devices to use edge triggered rather than level triggered interrupts. That might be too invasive though. */ Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message