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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A5A3EC433DF for ; Sun, 18 Oct 2020 09:57:09 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0A5F02137B for ; Sun, 18 Oct 2020 09:57:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="HgbbzbG6"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="Lcf4K01I" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A5F02137B 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-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q8qwWPKaaID82zlxAAR1APzE0eOsCFml7Fg6fKE3cD4=; b=HgbbzbG6vHEEH6nDPeYpH4WTF HY4AimeRipd9wjdOTaTKKcZKB+esAydo29YNi6WIO0ss6wvffRZRzbcd0VcyCCxV1Ijf5Lzf41HwL 0RxkmPW7W8vbluKgEZi4ffLcu1u8gR/zTBR9eRF3OXEw/LZb9XE/Spo59mTY5A7Z5mCyArJkyR10P Hx5JWwpFAavqVgwn1NGJtfplysOMs1mW/Jkl44bwPs1CY1Yr/4l1eaMG180bPZw2bFXf4X6ZYRBIL KpqFYZuSd2AwSVnxVsLQ7byq+4Nyj8XxTLoir+teT97hyGvQiIK5/KQ92ZF9LVQmwpG1467CRgRPF jkXY1+4Nw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kU5P4-00073m-DS; Sun, 18 Oct 2020 09:55:02 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kU5P0-0006v3-Mr for linux-arm-kernel@lists.infradead.org; Sun, 18 Oct 2020 09:54:59 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; 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=qEMPtsMLmphrg8Ai/5Jx8LIQzpGt/vPBENY1d0RHC0E=; b=Lcf4K01IIvsr9y0KWAyBU51kL tBL6KBpVPqVkHgTKZ8NomGJTe0GNS4C7pFwC22oHL20kyd6gBm2HOhmjqwLjR1cEbFQf+7z6ngNT/ yWNSWU3RKHlTp60XJzKTHAFdkMEw3CNV0oAD1Ij+wRmggkUZpZ9I5NXABiCqfoKe2SYalm2m1gfMv lMqRrXmJ/Yepa8+lc+QPNQmmsPQ3L4FlNdKxjrGwqPqeagjoYs1u3hMW1Fl0Nq2A+gHW+aJIOWHl5 GP44LwSAJ3TOpXTgLfqAJC6MsPO8dh3wlkt+tCOQkq9/WlMBajs7v0eYzw4fTWRz9k/7DT/epZdA9 nOo7Ap+lA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:47782) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kU5Lq-0004Al-VS; Sun, 18 Oct 2020 10:51:43 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1kU5Lm-00039F-1K; Sun, 18 Oct 2020 10:51:38 +0100 Date: Sun, 18 Oct 2020 10:51:38 +0100 From: Russell King - ARM Linux admin To: Linus Walleij Subject: Re: [PATCH 3/3] timekeeping: remove arch_gettimeoffset Message-ID: <20201018095137.GV1551@shell.armlinux.org.uk> References: <20201008154601.1901004-1-arnd@arndb.de> <20201008154601.1901004-4-arnd@arndb.de> <20201015095307.GS1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201018_055458_755399_4AA891BD X-CRM114-Status: GOOD ( 15.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , Stephen Boyd , netdev , Daniel Lezcano , "linux-kernel@vger.kernel.org" , John Stultz , Jakub Kicinski , Thomas Gleixner , "David S. Miller" , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Oct 15, 2020 at 02:38:07PM +0200, Linus Walleij wrote: > On Thu, Oct 15, 2020 at 11:53 AM Russell King - ARM Linux admin > wrote: > > > Don't be misled. It was not a matter of "enough gritty people", it > > was a matter that EBSA110 was blocking it. > > I remember that EBSA110 was quite different in that it had this > especially limited PIT timer, true that. At one point I even read > up on the details of it and then forgot them :/ Yes, it was so basic that it required software to reprogram it on every interrupt - it had no sensible periodic mode. The side effect of which was that unless done carefully, your timekeeping varied all over the place (so much that ntpd was not happy.) The final implementation made ntpd really quite happy on the machine despite the timer's weirdness, up until Linux stopped allowing interrupts to be nested. At that point, it was back to utterly crap timekeeping. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel