From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Simek Subject: Using serial driver 16550A in poll mode without interrupt connected Date: Wed, 12 Oct 2011 15:03:39 +0200 Message-ID: <4E95902B.7080204@monstr.eu> Reply-To: monstr@monstr.eu Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gx0-f174.google.com ([209.85.161.174]:45958 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752859Ab1JLNDm (ORCPT ); Wed, 12 Oct 2011 09:03:42 -0400 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org Cc: Greg Kroah-Hartman , LKML , Peter Korsgaard Hi, we have internal discussion around serial drivers and their usage without interrupts in polling mode. It is on FPGA with Microblaze/PPC/ARM and it is easy for us to have serial IP without IRQ connected to the interrupt controller. Driver is probed with no IRQ (NO_IRQ = -1 on Microblaze) 83e00000.serial: ttyS0 at MMIO 0x83e01003 (irq = -1) is a 16550A writing any data to ttyS0 return -1. Is there any reason no to use driver in poll mode especially for user applications not for consoles. Is it possible to use serial driver without IRQ - or blocking IRQ, etc.? Currently we care about uart16550 and uarlite. Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian