On Fri, Aug 19, 2011 at 5:21 PM, john stultz <johnstul@xxxxxxxxxx> wrote: > On Fri, 2011-08-19 at 16:56 -0400, Matt Turner wrote: >> With 2.6.37 the original rtctest program gives >> >> RTC Driver Test Example. >> >> RTC_UIE_ON ioctl: Invalid argument >> >> and the modified version hangs in the same way. :( > > Ok, so the AIE/alarm irq isn't working (but returns as if it should), > and in the older case, the UIE mode properly returned an error. > > So I'm guessing since we now use AIE mode interrupts to emulate UIE, the > UIE code thinks alarms will work and so doesn't return an error, > confusing the hwclock code. > >> With 2.6.37, hwclock did work: >> >> bcm91250a-be ~ # date >> Fri Aug 19 16:52:21 EDT 2011 >> bcm91250a-be ~ # hwclock --systohc >> bcm91250a-be ~ # date 082016522011 >> Sat Aug 20 16:52:00 EDT 2011 >> bcm91250a-be ~ # hwclock --hctosys >> bcm91250a-be ~ # date >> Fri Aug 19 16:53:02 EDT 2011 > > Running strace on the hwclock --hctosys might prove the theory above. > > >> With 3.1.0-rc2+, it does not >> bcm91250a-be ~ # date >> Fri Aug 19 16:54:32 EDT 2011 >> bcm91250a-be ~ # hwclock --systohc >> select() to /dev/rtc0 to wait for clock tick timed out >> bcm91250a-be ~ # date 082016542011 >> Sat Aug 20 16:54:00 EDT 2011 >> bcm91250a-be ~ # hwclock --hctosys >> select() to /dev/rtc0 to wait for clock tick timed out >> bcm91250a-be ~ # date >> Sat Aug 20 16:54:11 EDT 2011 >> >> So, even if the alarm never worked, there is some sort of regression here. > > Yea, since we depend on the alarm irq for more functionality now, it not > working in this case is causing more trouble. > > I suspect either fixing the driver alarm code so it either works or > provides a proper error code will resolve it. > > thanks > -john Indeed, looks like that's the case. 2.6.37: ioctl(3, PRESTO_GETMOUNT or RTC_UIE_ON, 0) = -1 EINVAL 3.1.0: ioctl(3, PRESTO_GETMOUNT or RTC_UIE_ON, 0) = 0 (Attaching full gz'd logs for posterity.) Thanks, Matt
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