From owner-freebsd-current Thu Nov 9 8: 1:36 2000 Delivered-To: freebsd-current@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 3F24037B479 for ; Thu, 9 Nov 2000 08:01:34 -0800 (PST) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.3/8.9.3) id LAA06059; Thu, 9 Nov 2000 11:01:06 -0500 (EST) (envelope-from wollman) Date: Thu, 9 Nov 2000 11:01:06 -0500 (EST) From: Garrett Wollman Message-Id: <200011091601.LAA06059@khavrinen.lcs.mit.edu> To: Bruce Evans Cc: current@FreeBSD.ORG Subject: Interrupt allocation In-Reply-To: References: <200011082018.NAA32387@harmony.village.org> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG < said: > - pci drivers "know" that pci interrupts are shareable and force > RF_SHAREABLE. Is this required by the pci spec? Yes. > - the isa compatibility code and pcvt force RF_SHAREABLE although isa > irqs are rarely shareable. This is a bug. I suspect it may be due to code rot, related to the removal of the ``conflicts'' keyword in config. > - sio forces !RF_SHAREABLE, but it is possible for sio interrupts to be > shared if they aren't fast. Well, you're welcome to make it do whatever you think is correct. > This overloads RF_SHAREABLE to mean that the device driver > supports sharing. Whether sharing is supported should not be an attribute of the device driver -- all drivers should support interrupt sharing, even in cases where the underlying hardware is ``known'' not to support it. (Having the drivers specify RF_SHAREABLE is a bug I introduced when I did the first port to new-bus.) If there are buses which need to be programmed to enable or disable sharing, that should be handled through a bus-specific mechanism (preferably automatically). Timesharing requires co-operation from both device and bus, but this is a completely different issue. No drivers currently support timesharing. `sio' at a minimum probably should, as it was the motivating example for adding that feature. (My laptop has three PnP sio ports: an internal modem, an external DB-9, and a dual-ported infrared transceiver. There are only two interrupts available among them.) -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message