From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933221AbbLROXg (ORCPT ); Fri, 18 Dec 2015 09:23:36 -0500 Received: from mail-wm0-f51.google.com ([74.125.82.51]:33822 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964926AbbLROT7 (ORCPT ); Fri, 18 Dec 2015 09:19:59 -0500 From: Daniel Lezcano To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mingo@kernel.org, Grygorii Strashko , Arnd Bergmann , John Stultz , Felipe Balbi , Tony Lindgren , Marc Zyngier , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com (open list:ARM/STI ARCHITECTURE) Subject: [PATCH 63/69] clocksource/drivers/arm_global_timer: Fix suspend resume Date: Fri, 18 Dec 2015 15:18:16 +0100 Message-Id: <1450448302-27429-63-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1450448302-27429-1-git-send-email-daniel.lezcano@linaro.org> References: <5672CB9E.7090707@linaro.org> <1450448302-27429-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Grygorii Strashko Now the System stall is observed on TI AM437x based board (am437x-gp-evm) during resuming from System suspend when ARM Global timer is selected as clocksource device (CPUIdle not enabled) - SysRq are working, but nothing else. The reason of stall is that ARM Global timer loses its contexts during System suspend: GT_CONTROL.TIMER_ENABLE = 0 (unbanked) GT_COUNTERx = 0 Hence, update ARM Global timer driver to reflect above behaviour - re-enable ARM Global timer on resume (GT_CONTROL.TIMER_ENABLE = 1) if not enabled. CC: Arnd Bergmann Cc: John Stultz Cc: Felipe Balbi Cc: Tony Lindgren Cc: Marc Zyngier Reviewed-by: Santosh Shilimkar Signed-off-by: Grygorii Strashko Signed-off-by: Daniel Lezcano --- drivers/clocksource/arm_global_timer.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c index f99be6b..d189d8c 100644 --- a/drivers/clocksource/arm_global_timer.c +++ b/drivers/clocksource/arm_global_timer.c @@ -195,12 +195,23 @@ static cycle_t gt_clocksource_read(struct clocksource *cs) return gt_counter_read(); } +static void gt_resume(struct clocksource *cs) +{ + unsigned long ctrl; + + ctrl = readl(gt_base + GT_CONTROL); + if (!(ctrl & GT_CONTROL_TIMER_ENABLE)) + /* re-enable timer on resume */ + writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL); +} + static struct clocksource gt_clocksource = { .name = "arm_global_timer", .rating = 300, .read = gt_clocksource_read, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .resume = gt_resume, }; #ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK -- 1.9.1