linux_dsm_epyc7002/Documentation/devicetree/bindings
Vincent Guittot 29e5f9441b dt-binding: arm/cpus.txt: fix dynamic-power-coefficient unit
The unit of dynamic-power-coefficient is described as mW/MHz/uV^2 whereas
its usage in the code assumes that unit is uW/MHz/V^2

In drivers/thermal/cpu_cooling.c, the code is :

power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv;
do_div(power, 1000000000);

which can be summarized as :
power (mW) = capacitance * freq_mhz/1000 * (voltage_mv/1000)^2
or
power (mW) = (capacitance * freq_mhz * (voltage_mv/1000)^2) / 1000
then
power (mW) = power (uW) / 1000
so
power (uW) = capacitance * freq_mhz * (voltage_mv/1000)^2

Furthermore, if we test basic values like :
voltage_mv = 1000mV = 1V
freq_mhz = 1000Mhz

The minimum possible power, when dynamic-power-coefficient equals 1, will
be with current unit:
min power = 1 * 1000  * (1000000)^2 = 10^15 mW
which is not realistic

With the unit used by the code, the min power is
min power =  1 * 1000 * 1^2 = 1000uW = 1mW which is far more realistic

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
2018-09-26 18:02:41 -05:00
..
arc
arm dt-binding: arm/cpus.txt: fix dynamic-power-coefficient unit 2018-09-26 18:02:41 -05:00
ata Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2018-08-24 13:20:33 -07:00
auxdisplay
board dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
bus ARM: SoC driver updates 2018-08-23 13:52:46 -07:00
c6x
clock ARM: Device-tree updates 2018-08-23 14:02:22 -07:00
connector
cpufreq ARM: SoC driver updates 2018-08-23 13:52:46 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-08-15 16:01:47 -07:00
devfreq dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional. 2018-07-18 13:58:37 +09:00
display fbdev changes for v4.19: 2018-08-23 15:44:58 -07:00
dma DMAengine updates for v4.19-rc1 2018-08-18 15:55:59 -07:00
edac
eeprom dt-bindings: at24: Add address-width property 2018-07-25 09:17:24 +02:00
extcon dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
firmware
fpga
fsi dt-bindings: fsi: Add optional chip-id to CFAMs 2018-07-23 16:27:32 +10:00
fuse
gnss
goldfish
gpio This is the bulk of GPIO changes for the v4.19 kernel cycle: 2018-08-15 21:35:38 -07:00
gpu
h8300
hsi dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
hwlock
hwmon
i2c Merge branch 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-08-21 17:40:46 -07:00
iio Staging/IIO patches for 4.19-rc1 2018-08-18 11:00:00 -07:00
infiniband dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2018-08-20 15:59:01 -07:00
interrupt-controller dt-bindings: riscv,cpu-intc: Cleanups from a missed review 2018-08-28 12:58:35 -07:00
iommu IOMMU Update for Linux v4.19 2018-08-24 13:10:38 -07:00
ipmi
leds - Core Frameworks 2018-08-20 15:41:37 -07:00
lpddr2
mailbox - xgene : potential null pointer fix 2018-08-16 10:16:08 -07:00
media media updates for v4.19-rc1 2018-08-15 18:29:14 -07:00
memory-controllers dt-bindings: mediatek: Add binding for mt2712 IOMMU and SMI 2018-07-18 17:01:04 +02:00
mfd - New Drivers 2018-08-20 15:38:44 -07:00
mips Devicetree updates for 4.19: 2018-08-14 12:41:49 -07:00
misc
mmc ARM: Device-tree updates 2018-08-23 14:02:22 -07:00
mtd Devicetree updates for 4.19: 2018-08-14 12:41:49 -07:00
mux dt-bindings: mux: add adi,adgs1408 2018-08-02 10:23:01 +02:00
nds32
net Merge branch 'akpm' (patches from Andrew) 2018-08-23 19:20:12 -07:00
nios2
nvmem dt-bindings: nvmem: imx-ocotp: add compatible string for imx6sll 2018-07-15 14:03:05 +02:00
openrisc/opencores
opp
pci pci-v4.19-changes 2018-08-16 09:21:54 -07:00
perf
phy USB/PHY patches for 4.19-rc1 2018-08-18 10:21:49 -07:00
pinctrl - New Drivers 2018-08-20 15:38:44 -07:00
pmem
power power supply and reset changes for the v4.19 series 2018-08-21 18:06:27 -07:00
powerpc dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
pps
ptp
pwm dt-bindings: pwm: Add MT7628 information 2018-08-20 11:35:44 +02:00
regmap
regulator Devicetree updates for 4.19: 2018-08-14 12:41:49 -07:00
remoteproc remoteproc updates for v4.19 2018-08-18 16:42:04 -07:00
reserved-memory treewide: correct "differenciate" and "instanciate" typos 2018-08-23 18:48:43 -07:00
reset ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
riscv
rng dt-bindings: crypto: Move prng binding to crypto 2018-07-27 19:04:31 +08:00
rtc RTC for 4.19 2018-08-20 16:30:27 -07:00
scsi
security/tpm dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
serial TTY/Serial driver patches for 4.19-rc1 2018-08-18 10:50:41 -07:00
serio
siox
slimbus
soc ARM: SoC driver updates 2018-08-23 13:52:46 -07:00
sound ARM: Device-tree updates 2018-08-23 14:02:22 -07:00
spi Devicetree updates for 4.19: 2018-08-14 12:41:49 -07:00
spmi
sram ARM: SoC driver updates 2018-08-23 13:52:46 -07:00
staging/iio/adc dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2018-08-24 13:03:51 -07:00
timer ARM: Device-tree updates 2018-08-23 14:02:22 -07:00
ufs scsi: ufs: dt-bindings: add document for hisi-ufs 2018-07-19 21:57:39 -04:00
usb USB/PHY patches for 4.19-rc1 2018-08-18 10:21:49 -07:00
virtio
w1
watchdog dt-bindings: watchdog: renesas-wdt: Document r8a774a1 support 2018-08-29 20:32:04 +02:00
x86
xillybus dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00
ABI.txt
chosen.txt
common-properties.txt
graph.txt
jailhouse.txt
numa.txt
property-units.txt
resource-names.txt
submitting-patches.txt
trivial-devices.txt
unittest.txt
vendor-prefixes.txt ARM: Device-tree updates 2018-08-23 14:02:22 -07:00
xilinx.txt dt-bindings: remove 'interrupt-parent' from bindings 2018-07-25 14:09:39 -06:00