On Tue, Jun 24, 2014 at 11:41:38AM +0100, Punit Agrawal wrote:
> "Javi Merino" <[email protected]> writes:
>
> > Hi Punit,
> >
> > On Wed, Jun 11, 2014 at 12:31:44PM +0100, Punit Agrawal wrote:
> >> Create a new event to trace when the temperature is above a trip
> >> point. Use the trace-point when handling non-critical and critical
> >> trip pionts.
> >>
> >> Cc: Zhang Rui <[email protected]>
> >> Cc: Eduardo Valentin <[email protected]>
> >> Cc: Steven Rostedt <[email protected]>
> >> Cc: Frederic Weisbecker <[email protected]>
> >> Cc: Ingo Molnar <[email protected]>
> >> Signed-off-by: Punit Agrawal <[email protected]>
> >> ---
> >> Hi Steven,
> >>
> >> I am facing an issue with partial trace being emitted when using
> >> __print_symbolic in this patch.
> >>
> >> When the trip_type is THERMAL_TRIP_ACTIVE (i.e., the first value in
> >> the symbol map), the emitted trace contains the corresponding string
> >> ("active"). But for other values of trip_type an empty string is
> >> emitted in the trace.
> >>
> >> I've looked at other uses of __print_symbolic in the kernel and don't
> >> see any difference in usage. Do you know what could be causing this or
> >> alternately have any pointers on how to debug this behaviour?
> >>
> >> Thanks.
> >> Punit
> >>
> >> drivers/thermal/fair_share.c | 7 ++++++-
> >> drivers/thermal/step_wise.c | 5 ++++-
> >> drivers/thermal/thermal_core.c | 2 ++
> >> include/trace/events/thermal.h | 30 ++++++++++++++++++++++++++++++
> >> 4 files changed, 42 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c
> >> index 944ba2f..2cddd68 100644
> >> --- a/drivers/thermal/fair_share.c
> >> +++ b/drivers/thermal/fair_share.c
> >> @@ -23,6 +23,7 @@
> >> */
> >>
> >> #include <linux/thermal.h>
> >> +#include <trace/events/thermal.h>
> >>
> >> #include "thermal_core.h"
> >>
> >> @@ -34,14 +35,18 @@ static int get_trip_level(struct thermal_zone_device
> >> *tz)
> >> {
> >> int count = 0;
> >> unsigned long trip_temp;
> >> + enum thermal_trip_type trip_type;
> >>
> >> if (tz->trips == 0 || !tz->ops->get_trip_temp)
> >> return 0;
> >>
> >> for (count = 0; count < tz->trips; count++) {
> >> tz->ops->get_trip_temp(tz, count, &trip_temp);
> >> - if (tz->temperature < trip_temp)
> >> + if (tz->temperature < trip_temp) {
> >> + tz->ops->get_trip_type(tz, count, &trip_type);
> >> + trace_thermal_zone_trip(tz, count, trip_type);
> >
> > This should be outside the if condition. You want to report when trip
> > points have been hit, like in the step_wise code below.
> >
>
> It turned out to be a bit more subtle than moving the trace outside the
> if.
True, it was more difficult than what I said.
> I have the below fixup with an added comment. Let me know if that
> doesn't solve the problem.
I don't have a reproducer, I just spotted it while reading the code.
The below fix seems to be the right thing.
> -- >8 --
> Subject: [PATCH] fixup! thermal: trace: Trace when temperature is above a
> trip point
>
> ---
> drivers/thermal/fair_share.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c
> index 2cddd68..6e0a3fb 100644
> --- a/drivers/thermal/fair_share.c
> +++ b/drivers/thermal/fair_share.c
> @@ -42,12 +42,19 @@ static int get_trip_level(struct thermal_zone_device *tz)
>
> for (count = 0; count < tz->trips; count++) {
> tz->ops->get_trip_temp(tz, count, &trip_temp);
> - if (tz->temperature < trip_temp) {
> - tz->ops->get_trip_type(tz, count, &trip_type);
> - trace_thermal_zone_trip(tz, count, trip_type);
> + if (tz->temperature < trip_temp)
> break;
> - }
> }
> +
> + /*
> + * count > 0 only if temperature is greater than first trip
> + * point, in which case, trip_point = count - 1
> + */
> + if (count > 0) {
> + tz->ops->get_trip_type(tz, count - 1, &trip_type);
> + trace_thermal_zone_trip(tz, count - 1, trip_type);
> + }
> +
> return count;
> }
>
> --
> 1.7.10.4
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