Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] PM: fix calculation mistake in roll-over cases | Date | Tue, 25 Oct 2011 15:08:40 +0200 |
| |
On Tuesday, October 25, 2011, vbyravarasu@nvidia.com wrote: > 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;
I'm not sure how this is supposed to improve things. Care to give more details?
Rafael
| |