Removing unwanted stuff from DTS

Hi Guys,

I have a few questions I was hoping you could help me with.

From my dmesg output I would like to resolve some bugs and remove undesired/not required functionality in the DTS.

First of all my hardware has the HDMI CEC pin floating and hence I would like to disable that to rid the following garbage in dmesg

[    1.030962] tegra_cec 3960000.tegra_cec: dt=1 start=0x03960000 end=0x03960FFF irq=390
[    1.031704] tegra_cec 3960000.tegra_cec: Unpowergate DISP: 0.
[    1.032758] tegra_cec 3960000.tegra_cec: Enable clock result: 0.
[    1.032786] tegra_cec 3960000.tegra_cec: tegra_cec_init started
[    1.033535] tegra_cec 3960000.tegra_cec: cec_add_sysfs ret=0
[    1.033542] tegra_cec 3960000.tegra_cec: probed

Q1: Is it enough/okay to simply set the tegra_cec status to “disable” ?

Q2a: My Custom board does not use the FAN PWM and FAN TACH pins on the Tegra TX1 but rather I have a dedicated FAN controller IC which Im controlling manually over I2C based on the temperature in my enclosure - Is there a way to disble/remove the Tegra FAN driver?

Q2b: If I disable the above will there still be hardware based thermal throttling in case the internal temperature sensors of the TX1 detects over temperature?

[ 1.638661] FAN dev name: pwm-fan
[ 1.638715] FAN:gpio request success.
[ 1.638723] FAN: can’t find tach_gpio
[ 1.638745] pwm_fan_driver pwm-fan: cap state:7, cap pwm:255
[ 1.638979] pwm_fan_driver pwm-fan: got pwm for fan. polarity is inversed
[ 1.638984] pwm_fan_driver pwm-fan: tach period: 1000
[ 1.639752] extcon-disp-state external-connection:disp-state: cable 47 state 1
[ 1.639756] Extcon AUX1(HDMI) enable
[ 1.640057] pwm_fan_driver pwm-fan: index 0: pwm=0, rpm=0, rru=40, rrd=40, state:2
[ 1.640063] pwm_fan_driver pwm-fan: index 1: pwm=80, rpm=1000, rru=2, rrd=2, state:2
[ 1.640068] pwm_fan_driver pwm-fan: index 2: pwm=120, rpm=2000, rru=1, rrd=1, state:2
[ 1.640072] pwm_fan_driver pwm-fan: index 3: pwm=160, rpm=3000, rru=1, rrd=1, state:2
[ 1.640076] pwm_fan_driver pwm-fan: index 4: pwm=255, rpm=4000, rru=1, rrd=1, state:3
[ 1.640080] pwm_fan_driver pwm-fan: index 5: pwm=255, rpm=5000, rru=1, rrd=1, state:3
[ 1.640084] pwm_fan_driver pwm-fan: index 6: pwm=255, rpm=6000, rru=1, rrd=1, state:3
[ 1.640088] pwm_fan_driver pwm-fan: index 7: pwm=255, rpm=7000, rru=1, rrd=1, state:4
[ 1.640093] pwm_fan_driver pwm-fan: index 8: pwm=255, rpm=10000, rru=1, rrd=1, state:4
[ 1.640098] pwm_fan_driver pwm-fan: index 9: pwm=255, rpm=11000, rru=1, rrd=1, state:4

Q3: my hardware does not use the Ethernet MAC (only WiFi/BT) **
** - how can I disable it so that the system is not wasting time loading it?

Q4: My hardware has no SATA or PCIe ports (PEX0, PEX1, PEX2 pins are all floating except RX pins which are grounded), I am using the USB0 flashing port, one USB3 port and the USB2 port. How can I disable the PCIe and SATA?


hello LasseRoedtnes

since you’re having your own customize board, you may also access Jetson TX1 OEM Product Design Guide via download center for reference.

it’s device tree to indicate the CEC compatible driver, clocks, and interrupts. you may set the status as disable for configuration. or, you may also disable it from kernel configure if you also like to disable driver to probe it.

you should check developer guide, Thermal Management for reference. it’s device tree for configuring a Thermal Zone for different trip points.