Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751456AbWJPE2x (ORCPT ); Mon, 16 Oct 2006 00:28:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751457AbWJPE2w (ORCPT ); Mon, 16 Oct 2006 00:28:52 -0400 Received: from mail01.verismonetworks.com ([164.164.99.228]:48040 "EHLO mail01.verismonetworks.com") by vger.kernel.org with ESMTP id S1751456AbWJPE2w (ORCPT ); Mon, 16 Oct 2006 00:28:52 -0400 Subject: Re: [PATCH] drivers/char/riscom8.c: save_flags()/cli()/sti() removal From: Amol Lad To: Alan Cox Cc: matthew@wil.cx, linux kernel , kernel Janitors In-Reply-To: <1160835602.5732.30.camel@localhost.localdomain> References: <1160739628.19143.376.camel@amol.verismonetworks.com> <1160835602.5732.30.camel@localhost.localdomain> Content-Type: text/plain Date: Mon, 16 Oct 2006 10:02:12 +0530 Message-Id: <1160973132.19143.402.camel@amol.verismonetworks.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 36 On Sat, 2006-10-14 at 15:20 +0100, Alan Cox wrote: > Ar Gwe, 2006-10-13 am 17:10 +0530, ysgrifennodd Amol Lad: > > Removed save_flags()/cli()/sti() and used (light weight) spin locks > > > > Three things I see that look problematic > 2. If the irq handler itself dumbly locks to fix this then we get > tty_flip_buffer_push() re-entering the other code paths and deadlocking > if low latency is enabled The comment above tty_flip_buffer_push() says "This function must not be called from IRQ context if tty->low_latency is set". In this case tty_flip_buffer_push() is called from IRQ context. Do you think tty->low_latency can still be set for this case ? or I misunderstood your statement completely... > 3. Some of the use of local_save/spin_lock_irq seems over-clever and > unneeded Let me know, I'll fix them too. > > Fixable but how about we just delete the file since it has been broken > for ages and nobody can be using it ? > If we cannot delete the file then we must fix it. It's not good the drivers using old and deprecated interfaces in current phase of kernel development. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/