On Thu, 2015-05-14 at 13:06 +0300, Aaro Koskinen wrote: > Hi, > > On Wed, May 13, 2015 at 06:39:40AM +1000, Benjamin Herrenschmidt wrote: > > On Tue, 2015-05-12 at 20:55 +0300, Aaro Koskinen wrote: > > > I'm running with HZ=100 so the values are still probably within > > > jiffy resolution, so perhaps the calculation should first do > > > idle = min(idle, total)? > > > > Does it gives you a reasonable output if you do that ? > > The below change fixes the idle system blinking behaviour. > > I'm also able to reproduce the leds going off during full CPU load case. > It seems there is some DMA error. Normally, reading rm->dma_regs->status > in the IRQ handler gives 0x8400. In the failure cases I've seen values > 0x8880 and 0x8980 - the IRQ will stop after this and it will need > paused -> started cycle before it gets going again (but sometimes fails > again soon after).
That's a bit worrysome, is that new ? Smells like faulting HW ... Ben. > A. > > diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c > index 048901a..3381fa59 100644 > --- a/drivers/macintosh/rack-meter.c > +++ b/drivers/macintosh/rack-meter.c > @@ -227,6 +227,7 @@ static void rackmeter_do_timer(struct work_struct *work) > > total_idle_ticks = get_cpu_idle_time(cpu); > idle_ticks = (unsigned int) (total_idle_ticks - rcpu->prev_idle); > + idle_ticks = min(idle_ticks, total_ticks); > rcpu->prev_idle = total_idle_ticks; > > /* We do a very dumb calculation to update the LEDs for now, _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
