On Friday, April 26, 2013 05:19:53 PM Zhang Rui wrote: > Commit 4ae46befb49d4173122e0afa995c4e93d01948a2 > introduces a regression that the fan is always on > even if the system is in idle state. > > My original idea in that commit is that: > when the current temperature is above the trip point, > keep the fan on, even if the temperature is dropping. > when the current temperature is below the trip point, > turn on the fan when the temperature is raising, > turn off the fan when the temperature is dropping. > > But this is what the code actually does: > when the current temperature is above the trip point, > the fan keeps on. > when the current temperature is below the trip point, > the fan is always on because thermal_get_trend() > in driver/acpi/thermal.c returns THERMAL_TREND_RAISING. > Thus the fan keeps running even if the system is idle. > > Fix this in drivers/acpi/thermal.c. > > https://bugzilla.kernel.org/show_bug.cgi?id=56591 > https://bugzilla.kernel.org/show_bug.cgi?id=56601 > https://bugzilla.kernel.org/show_bug.cgi?id=50041#c45 > > Patch should be applied to 3.7 stable kernel and later. > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > Tested-by: Matthias <morpheusxyz123@xxxxxxxx> > Tested-by: Ville Syrjälä <syrjala@xxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> # v3.7+ Applied. Thanks, Rafael > --- > drivers/acpi/thermal.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c > index 8470771..a33821c 100644 > --- a/drivers/acpi/thermal.c > +++ b/drivers/acpi/thermal.c > @@ -723,9 +723,19 @@ static int thermal_get_trend(struct thermal_zone_device *thermal, > return -EINVAL; > > if (type == THERMAL_TRIP_ACTIVE) { > - /* aggressive active cooling */ > - *trend = THERMAL_TREND_RAISING; > - return 0; > + unsigned long trip_temp; > + unsigned long temp = KELVIN_TO_MILLICELSIUS(tz->temperature, > + tz->kelvin_offset); > + if (thermal_get_trip_temp(thermal, trip, &trip_temp)) > + return -EINVAL; > + > + if (temp > trip_temp) { > + *trend = THERMAL_TREND_RAISING; > + return 0; > + } else { > + /* Fall back on default trend */ > + return -EINVAL; > + } > } > > /* > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
