From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752358Ab1JHL1F (ORCPT ); Sat, 8 Oct 2011 07:27:05 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:55301 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976Ab1JHL1D (ORCPT ); Sat, 8 Oct 2011 07:27:03 -0400 From: Juergen Beisert Organization: Pengutronix - Linux Solutions for Science and Industry To: Thomas Gleixner Subject: Serieal console on Samsung S3C6410 ARM11 CPU (Was [ANNOUNCE] 3.0.6-rt17) Date: Sat, 8 Oct 2011 13:26:58 +0200 User-Agent: KMail/1.9.10 Cc: LKML , "linux-rt-users" , linux-arm-kernel@lists.infradead.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201110081326.58731.jbe@pengutronix.de> X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: jbe@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner wrote: > I'm pleased to announce the 3.0.6-rt17 release. I have no idea where to search, but when I'm using the 3.0.6-rt17 on my Samsung S3C6410 ARM based system, the UART (serial console) does not work as expected. Typing only one char at a time is okay. Typing two chars immediately makes the system using 100 % CPU load and takes about 2 seconds to respond. It seems the interrupt handling is broken in the UART driver, but I don't know how to fix it. This with a simple cursor up (one char to get the last command) and a small pause to the next "ENTER" char: root@mini6410:~ cat /proc/interrupts | grep 18: 18: 5739107 s3c-uart s3c6400-uart Same again: root@mini6410:~ cat /proc/interrupts | grep 18: 18: 5739113 s3c-uart s3c6400-uart 6 interrupts seems reasonable. Now with cursor up and SPACE immediately, then a pause for ENTER: root@mini6410:~ cat /proc/interrupts | grep 18: 18: 5923815 s3c-uart s3c6400-uart 184702 interrupts looks strange. jbe -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | http://www.pengutronix.de/ |