Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 04/18] power: ab8500_fg: Replace msleep() with usleep_range() for greater accuracy | Date | Tue, 15 Jan 2013 13:23:28 +0000 |
| |
On Tuesday 15 January 2013, Lee Jones wrote: > > > @@ -956,7 +956,7 @@ static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di) > > > do { > > > vbat += ab8500_fg_bat_voltage(di); > > > i++; > > > - msleep(5); > > > + usleep_range(5000, 5001); > > > > If you're going to give a range that small > > you might as well use usleep instead. > > > > Otherwise, add some tolerance to allow any > > other coalesced wakeup to occur. > > I can't increase the tolerance, as I don't know how that would > effect the running of the system, and the person who would know > is off on parental leave.
The function only averages the voltage between a couple of readings. It won't change much if those register reads are slightly more uniformly timed. Note that the thread can still be preempted for a much longer time if anything else is running, and the entire interrupt handling in this driver looks so fragile that I would not rely on the interrupt actually happening at the right time anyway. I think it should first be debugged properly to remove the need for the enable_irq/disable_irq calls.
Arnd
| |