From owner-freebsd-hackers Mon Dec 20 21:41:53 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from oracle.dsuper.net (oracle.dsuper.net [205.205.255.1]) by hub.freebsd.org (Postfix) with ESMTP id 9F3E714BD0 for ; Mon, 20 Dec 1999 21:41:50 -0800 (PST) (envelope-from bmilekic@dsuper.net) Received: from oracle.dsuper.net (oracle.dsuper.net [205.205.255.1]) by oracle.dsuper.net (8.9.3/8.9.3) with ESMTP id AAA06112; Tue, 21 Dec 1999 00:41:49 -0500 (EST) Date: Tue, 21 Dec 1999 00:41:49 -0500 (EST) From: Bosko Milekic To: Alex Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: splimp for PCI In-Reply-To: <199912201706.JAA31593@www.geocrawler.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 20 Dec 1999, Alex wrote: !>This message was sent from Geocrawler.com by "Alex" !>Be sure to reply to that address. !> !>Hello, !>I'm little confuse to using splimp/splx in driver !>that support PCI board. IRQ is shared for PCI. !>Is using splimp can cause for some problem? !>Thank a lot !>Alex !> !>Geocrawler.com - The Knowledge Archive Here's my `first glance' shot at an answer: [ ;-) ] Nope, using splimp() will not cause problems in terms of shared IRQs. However, it may cause problems if you're blocking interrupt handlers of priorities that you don't want to. Shared IRQs are dealt with thanks to a linked list of handlers for each shared IRQ, which all end up being called as a result of at least one of the devices "registered" for that IRQ asserts an int request. Each device, however, is "registered" with its own 'mask,' and this mask should correspond to one of several given values, where _handlers_ executing at that priority level will be blocked as per the present priority level. If you haven't done so already, my suggestion is to take a look at spl(9) [e.g. `man 9 spl'], and, if still interested, taking a look at *some* of i386/isa/intr_machdep.c as well as most of sys/i386/i386/nexus.c -- which brings up the question: Is anybody _currently_ working on cleaning this stuff up, and completely getting rid of the remains of the "old" interface? Bosko. ...... . . . . . . . . . . . . . Bosko Milekic -- bmilekic@dsuper.net . . . . . . . . . . . ...... . . WWW: http://pages.infinit.net/bmilekic/ . ................................................ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message