Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753216AbaJIIIJ (ORCPT ); Thu, 9 Oct 2014 04:08:09 -0400 Received: from mail-qg0-f51.google.com ([209.85.192.51]:56421 "EHLO mail-qg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751147AbaJIIH7 (ORCPT ); Thu, 9 Oct 2014 04:07:59 -0400 MIME-Version: 1.0 In-Reply-To: <1412799101.28467.68.camel@acox1-desk.ger.corp.intel.com> References: <1412798258-23655-1-git-send-email-ricardo.ribalda@gmail.com> <1412798258-23655-4-git-send-email-ricardo.ribalda@gmail.com> <1412799101.28467.68.camel@acox1-desk.ger.corp.intel.com> From: Ricardo Ribalda Delgado Date: Thu, 9 Oct 2014 10:07:38 +0200 Message-ID: Subject: Re: [PATCH 03/12] serial_core: Handle TIOC[GS]RS485 ioctls. To: Alan Cox Cc: One Thousand Gnomes , linux-serial@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Alan > > What is the locking between setting/getting/driver use of the config ? > This really needs a lock (termios sem I think is perhaps appropriate > given when the values are normally referenced). I tried implementing it with the sermios sem ((&(uart_port)->state->port.tty->termios_rwsem)), but some drivers access the rs485 structure inside their irq handler. So I have see options here 1) Protect the structure with uart_port->lock spinlock 2) Assume that an assignment is atomic on critical sections where I cannot hold the rwsem. I think 1) is more correct. Any issues that I continue in this direction? Any better idea? Thanks! -- Ricardo Ribalda -- 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/