Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753805AbbK3Lwx (ORCPT ); Mon, 30 Nov 2015 06:52:53 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:42282 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753718AbbK3Lwv (ORCPT ); Mon, 30 Nov 2015 06:52:51 -0500 Subject: Re: [PATCH v3] clocksource: arm_global_timer: fix suspend resume To: "santosh.shilimkar@oracle.com" , Russell King , Daniel Lezcano , Thomas Gleixner , Srinivas Kandagatla , Maxime Coquelin References: <1448653624-25006-1-git-send-email-grygorii.strashko@ti.com> <565B9869.10800@oracle.com> CC: , , , , Arnd Bergmann , John Stultz , Felipe Balbi , Tony Lindgren , Santosh Shilimkar , Marc Zyngier From: Grygorii Strashko Message-ID: <565C3852.4000605@ti.com> Date: Mon, 30 Nov 2015 13:51:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <565B9869.10800@oracle.com> Content-Type: text/plain; charset="iso-8859-15"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2319 Lines: 68 On 11/30/2015 02:29 AM, santosh.shilimkar@oracle.com wrote: > On 11/27/15 11:47 AM, Grygorii Strashko wrote: >> 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. >> >> CC: Arnd Bergmann >> Cc: John Stultz >> Cc: Felipe Balbi >> Cc: Tony Lindgren >> Cc: Santosh Shilimkar >> Cc: Marc Zyngier >> Signed-off-by: Grygorii Strashko >> --- >> Changes in v3: >> - dropped all DT specific code >> Changes in v2: >> - suspend/resume simplified: nothing is stored any more and >> ARM GT just re-enabled >> Link on v2: >> https://lkml.org/lkml/2015/11/20/355 >> Link on v1: >> https://lkml.org/lkml/2015/11/13/456 >> > Looks reasonable to me. >> drivers/clocksource/arm_global_timer.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/clocksource/arm_global_timer.c >> b/drivers/clocksource/arm_global_timer.c >> index a2cb6fa..10d1417 100644 >> --- a/drivers/clocksource/arm_global_timer.c >> +++ b/drivers/clocksource/arm_global_timer.c >> @@ -195,12 +195,19 @@ static cycle_t gt_clocksource_read(struct >> clocksource *cs) >> return gt_counter_read(); >> } >> >> +static void gt_resume(struct clocksource *cs) >> +{ >> + /* re-enable timer on resume */ >> + writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL); > > Check if its disabled before enabling it. > Other than that, > Reviewed-by: Santosh Shilimkar Sure, I'll update. Thanks. -- regards, -grygorii -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/