Messages in this thread | | | Date | Mon, 19 Jun 2017 23:36:39 +0800 | From | Dong Aisheng <> | Subject | Re: [PATCH V2 2/2] timer: imx-tpm: add imx tpm timer support |
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On Tue, Jun 13, 2017 at 10:19:47AM +0200, Alexander Stein wrote: > On Tuesday 13 June 2017 15:58:45, Dong Aisheng wrote: > > diff --git a/drivers/clocksource/timer-imx-tpm.c > > b/drivers/clocksource/timer-imx-tpm.c new file mode 100644 > > index 0000000..940a4f75 > > --- /dev/null > > +++ b/drivers/clocksource/timer-imx-tpm.c > > @@ -0,0 +1,227 @@ > > [...] > > +static int tpm_set_next_event(unsigned long delta, > > + struct clock_event_device *evt) > > +{ > > + unsigned long next, now; > > + > > + next = readl(timer_base + TPM_CNT) + delta; > > + writel(next, timer_base + TPM_C0V); > > + now = readl(timer_base + TPM_CNT); > > What about: > > now = readl(timer_base + TPM_CNT); > > next = now + delta; > > writel(next, timer_base + TPM_C0V); > > return 0; > > > + return (int)((next - now) <= 0) ? -ETIME : 0; > > Can this error actually happen, even with your implementation?
Yes, i did observe some -ETIME when testing with nanosleep or hrtimer during programing min_delta event, especially when system is high loading. e.g. run GPU stress test.
Please also refer to another mail for details i just replied to Daniel.
Regards Dong Aisheng
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