From owner-freebsd-current Thu Nov 4 18:57:56 1999 Delivered-To: freebsd-current@freebsd.org Received: from dingo.cdrom.com (dingo.cdrom.com [204.216.28.145]) by hub.freebsd.org (Postfix) with ESMTP id 4FAD5157A9 for ; Thu, 4 Nov 1999 18:57:55 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost.cdrom.com [127.0.0.1]) by dingo.cdrom.com (8.9.3/8.8.8) with ESMTP id SAA00787; Thu, 4 Nov 1999 18:47:35 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Message-Id: <199911050247.SAA00787@dingo.cdrom.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Amancio Hasty Cc: Mike Smith , yokota@zodiac.mech.utsunomiya-u.ac.jp (Kazutaka YOKOTA), current@FreeBSD.ORG Subject: Re: vga driver and signal In-reply-to: Your message of "Thu, 04 Nov 1999 18:41:55 PST." <199911050241.SAA50513@rah.star-gate.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 04 Nov 1999 18:47:35 -0800 From: Mike Smith Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > The only real way to do this "right" is going to be to have the X > > server load a KLD, which will then be able to hook the relevant > > interrupt(s). Any other alternative involves interrupt delivery to > > user-space, which is just not practical. > > Hi Mike, > Your idea sounds intriguing . How should we wired the KLD to > the X server? or how will the KLD inform the X server that it > has received a vertical retrace interrupt . The X server would have to load the KLD when it starts. The KLD would have to contain _all_ of the code that would run when the interrupt triggered. You would still have absolutely no latency guarantee on delivery of the interrupt to the KLD; you'd have to check on entry to the handler to see whether you weren't already too late. Basically, the whole idea is just totally screwed. You shouldn't be trying to do this because it just can't be done right. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message