From patchwork Mon Oct 14 19:07:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Ripard X-Patchwork-Id: 3040261 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 2D0629F2B6 for ; Mon, 14 Oct 2013 20:52:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6803A201F0 for ; Mon, 14 Oct 2013 20:52:36 +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 2D9E720121 for ; Mon, 14 Oct 2013 20:52:35 +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 1VVp6r-0006Zj-UG; Mon, 14 Oct 2013 20:51:26 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VVp6W-00045P-FM; Mon, 14 Oct 2013 20:51:04 +0000 Received: from top.free-electrons.com ([176.31.233.9] helo=mail.free-electrons.com) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VVp5u-0003yV-Uk for linux-arm-kernel@lists.infradead.org; Mon, 14 Oct 2013 20:50:29 +0000 Received: by mail.free-electrons.com (Postfix, from userid 106) id 741828BD; Mon, 14 Oct 2013 22:50:10 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from localhost (189.58.26.109.rev.sfr.net [109.26.58.189]) by mail.free-electrons.com (Postfix) with ESMTPSA id E742981C; Mon, 14 Oct 2013 22:50:09 +0200 (CEST) From: Maxime Ripard To: daniel.lezcano@linaro.org, tglx@linutronix.de Subject: [PATCH 2/3] clocksource: sun4i: Report the minimum tick that we can program Date: Mon, 14 Oct 2013 21:07:47 +0200 Message-Id: <1381777668-32565-3-git-send-email-maxime.ripard@free-electrons.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1381777668-32565-1-git-send-email-maxime.ripard@free-electrons.com> References: <1381777668-32565-1-git-send-email-maxime.ripard@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131014_165027_236621_4B8CD65B X-CRM114-Status: UNSURE ( 7.87 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -1.7 (-) Cc: Maxime Ripard , linux-kernel@vger.kernel.org, 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-Virus-Scanned: ClamAV using ClamSMTP We need to wait for at least 2 clock cycles whenever we reprogram our clockevent timer. Report that the minimum number of ticks we can handle is 3 ticks, and remove 3 ticks to the interval programmed to reflect this. Signed-off-by: Maxime Ripard --- drivers/clocksource/sun4i_timer.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/clocksource/sun4i_timer.c b/drivers/clocksource/sun4i_timer.c index 8ead025..46008f9 100644 --- a/drivers/clocksource/sun4i_timer.c +++ b/drivers/clocksource/sun4i_timer.c @@ -37,6 +37,8 @@ #define TIMER_INTVAL_REG(val) (0x10 * (val) + 0x14) #define TIMER_CNTVAL_REG(val) (0x10 * (val) + 0x18) +#define TIMER_SYNC_TICKS 3 + static void __iomem *timer_base; static u32 ticks_per_jiffy; @@ -50,7 +52,7 @@ static void sun4i_clkevt_sync(void) { u32 old = readl(timer_base + TIMER_CNTVAL_REG(1)); - while ((old - readl(timer_base + TIMER_CNTVAL_REG(1))) < 3) + while ((old - readl(timer_base + TIMER_CNTVAL_REG(1))) < TIMER_SYNC_TICKS) cpu_relax(); } @@ -104,7 +106,7 @@ static int sun4i_clkevt_next_event(unsigned long evt, struct clock_event_device *unused) { sun4i_clkevt_time_stop(0); - sun4i_clkevt_time_setup(0, evt); + sun4i_clkevt_time_setup(0, evt - TIMER_SYNC_TICKS); sun4i_clkevt_time_start(0, false); return 0; @@ -187,8 +189,8 @@ static void __init sun4i_timer_init(struct device_node *node) sun4i_clockevent.cpumask = cpumask_of(0); - clockevents_config_and_register(&sun4i_clockevent, rate, 0x1, - 0xffffffff); + clockevents_config_and_register(&sun4i_clockevent, rate, + TIMER_SYNC_TICKS, 0xffffffff); } CLOCKSOURCE_OF_DECLARE(sun4i, "allwinner,sun4i-timer", sun4i_timer_init);