From owner-freebsd-multimedia Sat Mar 15 13:24:31 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id NAA10842 for multimedia-outgoing; Sat, 15 Mar 1997 13:24:31 -0800 (PST) Received: from whizzo.transsys.com (whizzo.TransSys.COM [144.202.42.10]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id NAA10832 for ; Sat, 15 Mar 1997 13:24:20 -0800 (PST) Received: from localhost.transsys.com (localhost.transsys.com [127.0.0.1]) by whizzo.transsys.com (8.8.3/8.7.3) with SMTP id QAA11159; Sat, 15 Mar 1997 16:24:12 -0500 (EST) Message-Id: <199703152124.QAA11159@whizzo.transsys.com> X-Mailer: exmh version 2.0gamma 1/27/96 To: Amancio Hasty cc: Steve Passe , multimedia@FreeBSD.org From: "Louis A. Mamakos" Subject: Re: bt848 driver patch References: <199703152051.MAA01140@rah.star-gate.com> In-reply-to: Your message of "Sat, 15 Mar 1997 12:51:16 PST." <199703152051.MAA01140@rah.star-gate.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 15 Mar 1997 16:24:12 -0500 Sender: owner-multimedia@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > Not sure why tuner exhibits the problem -- it could be because we temporarily > loose the video signal and at that point there is nothing that you can > do;except,for the driver to re-start the video capture process. I think it might be because the I^2C code bit-bangs the messages out, rather than having the Bt848 do it for you. It looks to me that interrupts are disabled during the timing loops that bash out the individual bits. I was talking to a buddy of mine about this just earlier today; we wondered what all that code in there was doing given the function in the chip itself. Perhaps it was just inherited from some other driver? This is most disturbing to me, when I'm trying to eek out every last millisecond of precision from NTP... hope we're not missing too many clock interrupts. louie