From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932254AbVKZPjC (ORCPT ); Sat, 26 Nov 2005 10:39:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964793AbVKZPjB (ORCPT ); Sat, 26 Nov 2005 10:39:01 -0500 Received: from smtp-106-saturday.nerim.net ([62.4.16.106]:10756 "EHLO kraid.nerim.net") by vger.kernel.org with ESMTP id S932254AbVKZPjA (ORCPT ); Sat, 26 Nov 2005 10:39:00 -0500 Date: Sat, 26 Nov 2005 16:40:25 +0100 From: Jean Delvare To: LKML Subject: Paused I/O versus regular I/O Message-Id: <20051126164025.66aae4f4.khali@linux-fr.org> X-Mailer: Sylpheed version 2.0.4 (GTK+ 2.6.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi all, Could anyone tell me what the difference is between "paused" I/O (inb_p, oub_p and friends) and regular I/O (inb, oub and friends)? I understand that the former includes some delays here and there, but how do I know when to use the paused variant, and when the non-paused variant is OK? The driver I am currently working on involves combined I/O access on the Super-I/O ports (0x2e and 0x2f being the address and data ports, respectively) and chip-specific combined I/O access (typically 0x295 and 0x296 being the address and data ports, respectively). I am using regular (non-paused) I/O and it seems to work well, but I was wondering if maybe combined I/O (when you write to a port to select an internal address, then read the data from another port) was supposed to be done using paused I/O. Can anyone clarify the situation? I couldn't find any documentation explaining *when* paused I/O must be used. Thanks, -- Jean Delvare