From patchwork Fri Sep 13 13:02:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 2884081 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3591F9F1E3 for ; Fri, 13 Sep 2013 13:03:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0C1D7202E6 for ; Fri, 13 Sep 2013 13:03:31 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 83944202E5 for ; Fri, 13 Sep 2013 13:03:29 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VKT1w-0001rY-Na; Fri, 13 Sep 2013 13:03:24 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VKT1u-00057l-Eb; Fri, 13 Sep 2013 13:03:22 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VKT1q-000568-Cx for linux-arm-kernel@lists.infradead.org; Fri, 13 Sep 2013 13:03:20 +0000 Received: from gallifrey.ext.pengutronix.de ([2001:6f8:1178:4:5054:ff:fe8d:eefb] helo=hardanger.do.blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1VKT1O-0003MG-AV; Fri, 13 Sep 2013 15:02:50 +0200 From: Marc Kleine-Budde To: linux-kernel@vger.kernel.org Subject: [PATCH] [PATCH] clocksource: tcb: fix min_delta calculation Date: Fri, 13 Sep 2013 15:02:45 +0200 Message-Id: <1379077365-18458-1-git-send-email-mkl@pengutronix.de> X-Mailer: git-send-email 1.8.4.rc3 X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130913_090318_767719_0856EE0D X-CRM114-Status: GOOD ( 12.68 ) X-Spam-Score: -2.8 (--) Cc: nicolas.ferre@atmel.com, Marc Pignat , john.stultz@linaro.org, kernel@pengutronix.de, Marc Kleine-Budde , Ronald Wahl , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The commit 77cc982 clocksource: use clockevents_config_and_register() where possible switches from manually calculating min_delta_ns (and others) and clockevents_register_device() to automatic calculation via clockevents_config_and_register(). During this conversation the "+ 1" in min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1; was lost. This leads to problems when programming clock events, resuling in e.g. a sleep(2) sleeping more than 3 seconds. The "+ 1" was added in the original code to fix a rounding problem in clockevent_delta2ns(), see http://permalink.gmane.org/gmane.linux.kernel/549744 for background information. This patch fixes the problem by increasing the min_delta to "2" ticks. Cc: Marc Pignat Cc: Ronald Wahl Acked-by: Shawn Guo Signed-off-by: Marc Kleine-Budde --- Changes since v1: - Improved description. Thanks to Ronald Wahl. drivers/clocksource/tcb_clksrc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index 8a61872..7cf6dc7 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) clkevt.clkevt.cpumask = cpumask_of(0); - clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff); + clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff); setup_irq(irq, &tc_irqaction); }