On Fri, Mar 03, 2017 at 06:50:06PM -0300, Javier Martinez Canillas wrote: > Hello Krzysztof, > > On 02/11/2017 05:14 PM, Krzysztof Kozlowski wrote: > > In Odroid XU3 Lite board, the temperature levels reported for thermal > > zone 0 were weird. In warm room: > > /sys/class/thermal/thermal_zone0/temp:32000 > > /sys/class/thermal/thermal_zone1/temp:51000 > > /sys/class/thermal/thermal_zone2/temp:55000 > > /sys/class/thermal/thermal_zone3/temp:54000 > > /sys/class/thermal/thermal_zone4/temp:51000 > > > > Sometimes after booting the value was even equal to ambient temperature > > which is highly unlikely to be a real temperature of sensor in SoC. > > > > The thermal sensor's calibration (trimming) is based on fused values. > > In case of the board above, the fused values are: 35, 52, 43, 58 and 43 > > (corresponding to each TMU device). However driver defined a minimum value > > for fused data as 40 and for smaller values it was using a hard-coded 55 > > instead. This lead to mapping data from sensor to wrong temperatures > > for thermal zone 0. > > > > Various vendor 3.10 trees (Hardkernel's based on Samsung LSI, Artik 10) > > do not impose any limits on fused values. Since we do not have any > > knowledge about these limits, use 0 as a minimum accepted fused value. > > This should essentially allow accepting any reasonable fused value thus > > behaving like vendor driver. > > > > The exynos5420-tmu-sensor-conf.dtsi is copied directly from existing > > exynso4412 with one change - the samsung,tmu_min_efuse_value. > > > > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> > > > > --- > > > > Testing on other Exynos542x boards is much appreciated. Especially I > > wonder what efuse values are there. > > I tested on both Exynos5422 Odroid XU4 and Exynos5800 Peach Pi boards. > > The temperatures levels reported for these two boards on a warm room are: > > Odroid XU4 > > # cat /sys/class/thermal/thermal_zone*/temp > 50000 > 50000 > 54000 > 51000 > 48000 > > Peach Pi > > # cat /sys/class/thermal/thermal_zone*/temp > 42000 > 44000 > 27000 <-- weird value for thermal zone 2 like zone 0 in your XU3 lite > 45000 > 45000 > > And the efuse values for the TMU devices are: > > Odroid XU4 > > TMU0 = 45 > TMU1 = 44 > TMU2 = 44 > TMU3 = 46 > TMU3 = 46 > > Peach Pi > > TMU0 = 44 > TMU1 = 46 > TMU2 = 36 > TMU3 = 53 > TMU3 = 46 > > The fused value for TMU2 is < 40 so that explains the weird temperature > level for thermal zone 2 in Peach. So after your patch, makes more sense: > > # cat /sys/class/thermal/thermal_zone*/temp > 41000 > 42000 > 45000 > 43000 > 43000 Great! Thanks for testing! > I wonder though if 0 is the best value or if we should just lower more > to cover the used e-fuse values in Exynos5 boards. But as you said, > we have no knowledge about these limits... Yeah... we could set value of 10 or 20... but that would be blind shot. > > Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> > Tested-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> > Thanks, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
