From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965005AbWFNPeA (ORCPT ); Wed, 14 Jun 2006 11:34:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965007AbWFNPeA (ORCPT ); Wed, 14 Jun 2006 11:34:00 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:1293 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S965005AbWFNPd7 (ORCPT ); Wed, 14 Jun 2006 11:33:59 -0400 Date: Wed, 14 Jun 2006 16:33:53 +0100 From: Russell King To: Stuart MacDonald Cc: linux-kernel@vger.kernel.org Subject: Re: serial_core: verify_port() in wrong spot? Message-ID: <20060614153353.GB17432@flint.arm.linux.org.uk> Mail-Followup-To: Stuart MacDonald , linux-kernel@vger.kernel.org References: <20060609162320.GA11997@flint.arm.linux.org.uk> <093501c68bee$6aef1ad0$294b82ce@stuartm> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <093501c68bee$6aef1ad0$294b82ce@stuartm> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 09, 2006 at 01:59:13PM -0400, Stuart MacDonald wrote: > From: Russell King [rmk@arm.linux.org.uk] > > I'd rather verify_port didn't get used for that - it's purpose is to > > validate changes the admin makes to the port. > > I did figure out that's what it's currently used as, but I didn't want > to introduce a whole new call just to verify that the UART has 9bit > capability. > > Why aren't user changes validated? The only things which users can change is low latency, the alternative (deprecated) "38400-baud" baud rates, and the custom divisor. None of these depend on the low level driver, so there's no point asking the low level driver to validate them. > 9bit mode is much more than just words of 9 bit length. Parity is > gone, replaced by the 9th bit; reads and writes have to treat the > buffers driver-side buffers as 16 bit-wide instead of 8-bit; reads and > writes to the hardware are correspondingly different; there are new > interrupts; software flow control is gone; there's special address > matching and a new ioctl to set that up. Well, I'll have to read up on this before I can comment any further. At the moment I don't feel qualified to answer your questions. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core