From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932217AbWFSJca (ORCPT ); Mon, 19 Jun 2006 05:32:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932241AbWFSJca (ORCPT ); Mon, 19 Jun 2006 05:32:30 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:14601 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S932217AbWFSJc3 (ORCPT ); Mon, 19 Jun 2006 05:32:29 -0400 Date: Mon, 19 Jun 2006 10:32:19 +0100 From: Russell King To: Alan Cox Cc: gouji , "'LKML'" Subject: Re: About the fixes of /drivers/serial/8250.C in 2.6.17-rc6 for avoiding habbg-up Message-ID: <20060619093219.GA26941@flint.arm.linux.org.uk> Mail-Followup-To: Alan Cox , gouji , 'LKML' References: <000d01c6934c$f25c9870$f4647c0a@GOUJI> <1150708994.2503.3.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1150708994.2503.3.camel@localhost.localdomain> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 19, 2006 at 10:23:14AM +0100, Alan Cox wrote: > Ar Llu, 2006-06-19 am 12:03 +0900, ysgrifennodd gouji: > > In /drivers/serial/8250.C of 2.6.17-rc6, > > > > these fixes are adapted for avoinding the problem of hang-up > > while TTY write and console write from kernel conflicted. > > Yes, there is a bug in this version that was not in the one I submitted, > someone added an improvement. I disagree - in the non-oops_in_progress case, your version and the merged version are 100% identical - see http://marc.theaimsgroup.com/?l=linux-kernel&m=114657841432447&w=2 However, you never responded to my answers to your two questions in that email, which came with the patch which was merged. > > + if (oops_in_progress) { > > + locked = spin_trylock_irqsave(&up->port.lock, flags); > > + } else > > + spin_lock_irqsave(&up->port.lock, flags); > > + > > It could always use spin_trylock_irqsave(). The oops in progress > optimisation makes some sense initially but there are many console > printk users that can occur during serial I/O in exceptional cases. > > It's not an easy problem to solve with the current serial locking. I don't have the initial email from ysgrifennodd gouji, and neither do the lkml archives. What's the problem? -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core