From owner-freebsd-current Thu Oct 17 10:39:34 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1D19037B401 for ; Thu, 17 Oct 2002 10:39:33 -0700 (PDT) Received: from mail.sandvine.com (sandvine.com [199.243.201.138]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6773843E6A for ; Thu, 17 Oct 2002 10:39:32 -0700 (PDT) (envelope-from don@sandvine.com) Received: by mail.sandvine.com with Internet Mail Service (5.5.2653.19) id <42S949X2>; Thu, 17 Oct 2002 13:39:28 -0400 Message-ID: From: Don Bowman To: "'Kenneth P. Stox'" , FreeBSD current users Subject: RE: Dedicating an interrupt to a PC-Card slot Date: Thu, 17 Oct 2002 13:39:27 -0400 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > From: Kenneth P. Stox [mailto:stox@imagescape.com] > > Well, I decided to have some fun and see if I could get a > Novatel Merlin > C-201 wireless modem running under FreeBSD. It seems I have run into a > bit of a roadblock. It appears that the C-201 will only speak, through > it's 16550 UART, at a speed of 230400. As such it need to have fast > interrupt support, which only seems possible with a dedicated > interrupt. Doesn't sound like that fast an interrupt. The 16550 has a 16-byte send and receive fifo. Set the rx interrupt @ 14, and the tx @ 2. 230400/8 = 28800 chars /s 28800 / 14 = 2057 interrupts / s. This should be well within reach of a pentium-class machine. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message