From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750852AbWFTUHh (ORCPT ); Tue, 20 Jun 2006 16:07:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750861AbWFTUHh (ORCPT ); Tue, 20 Jun 2006 16:07:37 -0400 Received: from nz-out-0102.google.com ([64.233.162.202]:12703 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1750852AbWFTUHg (ORCPT ); Tue, 20 Jun 2006 16:07:36 -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:mime-version:content-type:content-transfer-encoding:content-disposition; b=EAuwyAa5QSQz73AKrJW1+HJVOlLDk7eb9d8pw6WlmBR7btRjQoaQzM0QbvJx+hMYHumJF4tCqGs28Sw1ZBbtOs7UwndxhiMg8SlqlOplrJg3QyOWP0WNsl1kIpC06oD1XUKesuuyEw54+wgXnxkjJK/cR+NHKg1eaYwERJFRgq0= Message-ID: <7f45d9390606201307yfdb8aadn4d00a6afeba0b09b@mail.gmail.com> Date: Tue, 20 Jun 2006 14:07:36 -0600 From: "Shaun Jackman" Reply-To: "Shaun Jackman" To: LKML Subject: TL16C752B DUART: MCR_OUT2 disables interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The datasheet I have for the TL16C752B labels the MCR_OUT1 bit as `FIFO Rdy enable' and the MCR_OUT2 bit as `IRQ enable'. The latter bit concerns me. The 8250.c driver sets MCR_OUT2 by default; however, if the user space clears MCR_OUT2 (through an ioctl TIOCMSET operation or similar), it seems to me that interrupts for that UART will stop working. Can someone confirm my suspicion? I'd expect that clearing/setting the OUT1 and OUT2 pins from user space should be an innocuous operation. Disabling interrupts is a fairly nasty side effect. Please cc me in your reply. Cheers, Shaun