From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756862AbcIPFtm (ORCPT ); Fri, 16 Sep 2016 01:49:42 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:36420 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754064AbcIPFtd (ORCPT ); Fri, 16 Sep 2016 01:49:33 -0400 From: Brian Norris To: Daniel Lezcano , Thomas Gleixner Cc: Mark Rutland , Stephen Boyd , , Marc Zyngier , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Brian Norris Subject: [PATCH] clocksource: arm_arch_timer: Don't assume clock runs in suspend Date: Fri, 16 Sep 2016 13:49:17 +0800 Message-Id: <20160916054917.16930-1-briannorris@chromium.org> X-Mailer: git-send-email 2.8.1.340.g018a5d0.dirty Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 4fbcdc813fb9 ("clocksource: arm_arch_timer: Use clocksource for suspend timekeeping"), this driver assumes that the ARM architected timer keeps running in suspend. This is not the case for some ARM SoCs, depending on the HW state used for system suspend. Let's not assume that all SoCs support this, and instead only support this if the device tree explicitly tells us it's "always on". In all other cases, just fall back to the RTC. This should be relatively harmless. It seems fair to key the system-suspend behavior off the same property used for C3STOP, since if the timer doesn't keep context for CPU sleep, it likely doesn't for system sleep either. Signed-off-by: Brian Norris --- drivers/clocksource/arm_arch_timer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 57700541f951..e28677a34f02 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -490,7 +490,7 @@ static struct clocksource clocksource_counter = { .rating = 400, .read = arch_counter_read, .mask = CLOCKSOURCE_MASK(56), - .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static struct cyclecounter cyclecounter = { @@ -526,6 +526,8 @@ static void __init arch_counter_register(unsigned type) clocksource_counter.name = "arch_mem_counter"; } + if (!arch_timer_c3stop) + clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; start_count = arch_timer_read_counter(); clocksource_register_hz(&clocksource_counter, arch_timer_rate); cyclecounter.mult = clocksource_counter.mult; -- 2.8.1.340.g018a5d0.dirty