From owner-freebsd-current Thu Nov 4 19: 8: 8 1999 Delivered-To: freebsd-current@freebsd.org Received: from rah.star-gate.com (216-200-29-190.snj0.flashcom.net [216.200.29.194]) by hub.freebsd.org (Postfix) with ESMTP id 8BABE155D5 for ; Thu, 4 Nov 1999 19:08:04 -0800 (PST) (envelope-from hasty@rah.star-gate.com) Received: from rah.star-gate.com (localhost.star-gate.com [127.0.0.1]) by rah.star-gate.com (8.9.3/8.8.8) with ESMTP id TAA50795; Thu, 4 Nov 1999 19:05:41 -0800 (PST) (envelope-from hasty@rah.star-gate.com) Message-Id: <199911050305.TAA50795@rah.star-gate.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Mike Smith Cc: 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 18:47:35 PST." <199911050247.SAA00787@dingo.cdrom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 04 Nov 1999 19:05:41 -0800 From: Amancio Hasty 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. Hi Mike I should be trying to do this for it can have interesting applications such as a Tivo player. Not sure what the problem with interrupt latency is ... Can you elaborate a little bit more ? Tnks! -- Amancio Hasty hasty@rah.star-gate.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message