From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: Hang in uart_block_til_ready() Date: Sun, 2 Apr 2006 16:23:50 +0100 Message-ID: <20060402152350.GA5283@flint.arm.linux.org.uk> References: <20060402135138.GC2954@hansmi.ch> <20060402143827.GA3565@flint.arm.linux.org.uk> <20060402151739.GA402@hansmi.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([212.18.232.186]:32019 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1750855AbWDBPXz (ORCPT ); Sun, 2 Apr 2006 11:23:55 -0400 Content-Disposition: inline In-Reply-To: <20060402151739.GA402@hansmi.ch> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Michael Hanselmann Cc: linux-serial@vger.kernel.org On Sun, Apr 02, 2006 at 05:17:39PM +0200, Michael Hanselmann wrote: > Hello Russell > > On Sun, Apr 02, 2006 at 03:38:27PM +0100, Russell King wrote: > > On Sun, Apr 02, 2006 at 03:51:38PM +0200, Michael Hanselmann wrote: > > > I've discovered a problem where I'm not sure wether it's an error in the > > > kernel or in the hardware. > > > It's neither - it's a bug in your test program. If you want "callout" > > semantics, open the port using O_NONBLOCK mode. > > I've now patched screen(1) and it works, but one thing is amazing me. > The other computer I wrote about has the serial console on ttyS0 and > starting screen(1) on the serial console works. Here's the relevant > strace part: Have you checked the state of the DCD line in both cases? Look in /proc/tty/driver/serial. > Am I going correct that this is a bug in screen(1) and it only works on > the first box by some mysterious reason? Mabye some timing issue? Probably "works" on the first box because it happens to have DCD asserted on the real serial port. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core