From owner-freebsd-hackers@FreeBSD.ORG Mon Jun 18 15:40:16 2007 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DBD1E16A475 for ; Mon, 18 Jun 2007 15:40:16 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.174]) by mx1.freebsd.org (Postfix) with ESMTP id C468F13C4BB for ; Mon, 18 Jun 2007 15:40:16 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from mac.com (smtpin02-en2 [10.13.10.147]) by smtpout.mac.com (Xserve/smtpout04/MantshX 4.0) with ESMTP id l5IFeFGn009418; Mon, 18 Jun 2007 08:40:15 -0700 (PDT) Received: from [172.16.1.5] (209-128-86-226.bayarea.net [209.128.86.226]) (authenticated bits=0) by mac.com (Xserve/smtpin02/MantshX 4.0) with ESMTP id l5IFe6lp006578 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Mon, 18 Jun 2007 08:40:13 -0700 (PDT) In-Reply-To: <200706180859.15865.christian.kandeler@hob.de> References: <200706151541.51913.christian.kandeler@hob.de> <8D1F83C2-C7A6-4C86-88BE-17DD516DA4D9@mac.com> <200706180859.15865.christian.kandeler@hob.de> Mime-Version: 1.0 (Apple Message framework v752.3) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <5DD69BA8-586A-4B7F-B9B4-ECA9C74F41F3@mac.com> Content-Transfer-Encoding: 7bit From: Marcel Moolenaar Date: Mon, 18 Jun 2007 08:39:48 -0700 To: Christian Kandeler X-Mailer: Apple Mail (2.752.3) X-Brightmail-Tracker: AAAAAA== X-Brightmail-scanned: yes Cc: freebsd-hackers@freebsd.org Subject: Re: Question about serial console code X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Jun 2007 15:40:16 -0000 On Jun 17, 2007, at 11:59 PM, Christian Kandeler wrote: >> If the UART has no FIFO (in the 16550-sense), then sc_txfifosz >> is still 1. > > But where is this set? The ns8250_bus_probe() function returns > early when it > detects a FIFO-less device, leaving sc_txfifosz at its pre- > initialized value > (i.e. zero). And it doesn't seem to get set anywhere else, either. Uhm, on line 817 in uart_dev_ns8250.c, which falls in function uart_bus_probe(), both the rx and tx fifo sizes are set to 1. This is for the case there's no fifo. FYI, -- Marcel Moolenaar xcllnt@mac.com