From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C654EC43441 for ; Tue, 13 Nov 2018 09:20:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 470C2224E0 for ; Tue, 13 Nov 2018 09:20:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="f5y1M3El" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 470C2224E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731587AbeKMTRz (ORCPT ); Tue, 13 Nov 2018 14:17:55 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:51530 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727530AbeKMTRz (ORCPT ); Tue, 13 Nov 2018 14:17:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=JHTF+YLgdj1PtG9j9n0BfGIqaZn5MXxRBHxRAKlnHRA=; b=f5y1M3ElUrr/lgUz627h7c169 tc99J2eosmkHImv2suEQY01BE/Dm+7QVTdvGpFQ1MDfEiTYwEOp1vXbVE/UayW3PmBmZUEF2picmf VUVXWOS3tEl8hc+fvq4isYXuGjDQKsMXsbOh0+m+yBeA8jGx/pI4+afE5D493oAUpEQh8=; Received: from n2100.armlinux.org.uk ([2001:4d48:ad52:3201:214:fdff:fe10:4f86]:39398) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gMUrw-00074Z-Gq; Tue, 13 Nov 2018 09:20:24 +0000 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1gMUrq-0007GQ-5d; Tue, 13 Nov 2018 09:20:18 +0000 Date: Tue, 13 Nov 2018 09:20:13 +0000 From: Russell King - ARM Linux To: Finn Thain Cc: Christoph Hellwig , Geert Uytterhoeven , Arnd Bergmann , Stephen N Chivers , Thomas Gleixner , Daniel Lezcano , John Stultz , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH 01/13] arm: Fix mutual exclusion in arch_gettimeoffset Message-ID: <20181113092012.GI30658@n2100.armlinux.org.uk> References: <20181112083422.GA19695@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 13, 2018 at 02:39:00PM +1100, Finn Thain wrote: > On Mon, 12 Nov 2018, Christoph Hellwig wrote: > > > On Mon, Nov 12, 2018 at 03:12:39PM +1100, Finn Thain wrote: > > > Implementations of arch_gettimeoffset are generally not re-entrant and > > > assume that interrupts have been disabled. Unfortunately this > > > pre-condition got broken in v2.6.32. > > > > > > Fixes: 5cfc8ee0bb51 ("ARM: convert arm to arch_gettimeoffset()") > > > Signed-off-by: Finn Thain > > > > This looks like a sensible fix for -stable backporting. But with m68k > > converted over it might be time for these two arm platforms to either > > be converted to the clocksource API or to be dropped.. > > > > You could remove the old arch_gettimeoffset API without dropping any > platforms. > > If no-one converts a given platform to the clocksource API it would mean > that the default 'jiffies' clocksource will get used on that platform. > > Clock resolution and timer precision would be degraded, but that might not > matter. > > Anyway, if someone who has this hardware is willing to test a clocksource > API conversion, they can let me know and I'll attempt that patch. There's reasons why that's not appropriate - such as not having two separate timers in order to supply a clocksource and separate clock event. Not all hardware is suited to the clocksource + clockevent idea. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up