Thermal: initialize thermal zone device correctly

After thermal zone device registered, as we have not read any
temperature before, thus tz->temperature should not be 0,
which actually means 0C, and thermal trend is not available.
In this case, we need specially handling for the first
thermal_zone_device_update().

Both thermal core framework and step_wise governor is
enhanced to handle this. And since the step_wise governor
is the only one that uses trends, so it's the only thermal
governor that needs to be updated.

CC: <stable@vger.kernel.org> #3.18+
Tested-by: Manuel Krause <manuelkrause@netscape.net>
Tested-by: szegad <szegadlo@poczta.onet.pl>
Tested-by: prash <prash.n.rao@gmail.com>
Tested-by: amish <ammdispose-arch@yahoo.com>
Tested-by: Matthias <morpheusxyz123@yahoo.de>
Reviewed-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
This commit is contained in:
Zhang Rui 2015-10-30 16:31:47 +08:00
parent 74bf8efb5f
commit bb431ba26c
4 changed files with 36 additions and 4 deletions

View file

@ -43,6 +43,9 @@
/* Default weight of a bound cooling device */
#define THERMAL_WEIGHT_DEFAULT 0
/* use value, which < 0K, to indicate an invalid/uninitialized temperature */
#define THERMAL_TEMP_INVALID -274000
/* Unit conversion macros */
#define DECI_KELVIN_TO_CELSIUS(t) ({ \
long _t = (t); \