From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261497AbVFFPEH (ORCPT ); Mon, 6 Jun 2005 11:04:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261498AbVFFPEG (ORCPT ); Mon, 6 Jun 2005 11:04:06 -0400 Received: from zproxy.gmail.com ([64.233.162.198]:43490 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S261497AbVFFPDv convert rfc822-to-8bit (ORCPT ); Mon, 6 Jun 2005 11:03:51 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=aOq3Fea2biV6g/pUWmsjBDPv2II2tH3f7xa7rhkRlogIn+XA5ZDPPg11Z8bFH6Y30XtdBZj+8LTkNoBLsT0lC9qsSwXF+EWRZuvEXJFpmR5ytHMnOhay8Y7YHHGPvTco1beXHDrhDbb26FXGhFzIxwsCB2+mZDV8KdYOYof3R8E= Message-ID: <4789af9e0506060803161a8382@mail.gmail.com> Date: Mon, 6 Jun 2005 09:03:50 -0600 From: Jim Ramsay Reply-To: Jim Ramsay To: Bjorn Helgaas Subject: Re: Bug in 8520.c - port.type not set for serial console Cc: linux-kernel@vger.kernel.org In-Reply-To: <200505311625.46084.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <4789af9e05053015385667923@mail.gmail.com> <200505311625.46084.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 5/31/05, Bjorn Helgaas wrote: > On Monday 30 May 2005 4:38 pm, Jim Ramsay wrote: > > I am attempting to get the 8520.c driver's serial console working with > > a 16550A UART implementation, and have run into what I consider to be > > a bug: In short, the proper 'port.type' for this serial port is not > > set until the module init (serial8250_init) is called, so the FCR is > > set incorrectly during serial8250_console_init for any port type which > > is different than UNKNOWN. > > > > The exact problem is that the FCR is being set to '0x0' for a port > > type of 'UNKNOWN', when for my specific 16550A, it should be set to > > '0xC1' - and this makes my screen fill with empty characters instead > > of the printk output I need. > > Shouldn't a 16550A UART work correctly with FCR==0x0, i.e., with FIFOs > disabled? Is your UART broken? That's a good question. I'll me looking into this in the near future. > Serial console output is always polled, one character at a time, so > you shouldn't need FIFOs until later. True, as long as it works that way... so far I haven't seen it actually function properly yet with FCR set to 0. -- Jim Ramsay "Me fail English? That's unpossible!"