Messages in this thread Patch in this message |  | | | From | vbyravarasu@nvidia ... | | Subject | [PATCH] PM: fix calculation mistake in roll-over cases | | Date | Tue, 25 Oct 2011 15:50:52 +0530 |
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From: venu byravarasu <vbyravarasu@nvidia.com>
In case of jiffies roll over, delta is made zero. Hence fixing it, after taking roll over into consideration.
Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com> --- 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
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