From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932623Ab1JYKQr (ORCPT ); Tue, 25 Oct 2011 06:16:47 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:6052 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932467Ab1JYKQp (ORCPT ); Tue, 25 Oct 2011 06:16:45 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Tue, 25 Oct 2011 03:16:44 -0700 From: vbyravarasu@nvidia.com To: pavel@ucw.cz, rjw@sisk.pl, len.brown@intel.com, gregkh@suse.de Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, vbyravarasu@nvidia.com Subject: [PATCH] PM: fix calculation mistake in roll-over cases Date: Tue, 25 Oct 2011 15:50:52 +0530 Message-Id: <1319538052-2480-1-git-send-email-vbyravarasu@nvidia.com> X-Mailer: git-send-email 1.7.1.1 X-NVConfidentiality: public Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: venu byravarasu In case of jiffies roll over, delta is made zero. Hence fixing it, after taking roll over into consideration. Signed-off-by: venu byravarasu --- When jiffies roll over, calculation of time spent in the current state (stored in variable 'delta') is incorrect. Hence fixing it, after taking roll over into consideration. drivers/base/power/runtime.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 1079e03..bd93fb0 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -30,12 +30,13 @@ static int rpm_suspend(struct device *dev, int rpmflags); void update_pm_runtime_accounting(struct device *dev) { unsigned long now = jiffies; - int delta; + unsigned long delta; + unsigned long max_num = ~0; delta = now - dev->power.accounting_timestamp; - if (delta < 0) - delta = 0; + if (now < dev->power.accounting_timestamp) + delta = max_num - dev->power.accounting_timestamp + now; dev->power.accounting_timestamp = now; -- 1.7.1.1