nvidia@ubuntu:~$ ddcutil detect
(i2c_set_addr ) set_addr(/dev/i2c-0,I2C_SLAVE,0x50) failed, error = EBUSY
No displays found.
Is DDC/CI enabled in the monitor’s on screen display?
Run “ddcutil environment” to check for system configuration problems.
nvidia@ubuntu:~$ ddcutil environment
The following tests probe the runtime environment using multiple overlapping methods.
*** Basic System Information ***
ddcutil version: 1.2.2
/proc/version:
Linux version 5.15.136-tegra (buildbrain@mobile-u64-6367-d8000) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2022.08) 11.3.0, GNU ld (GNU Binutils) 2.38) #1 SMP PREEMPT Mon May 6 09:56:39 PDT 2024
Architecture: aarch64
Distributor id: Ubuntu
Release: 22.04
Found a known architecture
/proc/cmdline:
root=PARTUUID=5cce7512-1504-4620-9f70-6e6153ab29c3 rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 nospectre_bhb video=efifb:off console=tty0 nv-auto-config bl_prof_dataptr=2031616@0x471E10000 bl_prof_ro_ptr=65536@0x471E00000
*** Primary Check 1: Identify video card and driver ***
Obtaining card and driver information from /sys…
*** Primary Check 2: Check that /dev/i2c-* exist and writable ***
Current user: nvidia (1000)
Checking /dev/i2c-* devices…
Devices /dev/i2c-* must exist and the logged on user must have read/write permission for those devices (or at least those devices associated
with monitors).
Typically, this access is enabled by:
- setting the group for /dev/i2c-* to i2c
- setting group RW permissions for /dev/i2c-*
- making the current user a member of group i2c
Alternatively, this can be enabled by just giving everyone RW permission
The following tests probe for these conditions.
Checking for /dev/i2c-* devices…
crw-rw---- 1 root i2c 89, 0 6月 6 13:35 /dev/i2c-0
crw-rw---- 1 root i2c 89, 1 6月 6 13:35 /dev/i2c-1
crw-rw---- 1 root i2c 89, 10 6月 6 13:35 /dev/i2c-10
crw-rw---- 1 root i2c 89, 11 6月 6 13:35 /dev/i2c-11
crw-rw---- 1 root i2c 89, 2 6月 6 13:35 /dev/i2c-2
crw-rw---- 1 root i2c 89, 4 6月 6 13:35 /dev/i2c-4
crw-rw---- 1 root i2c 89, 5 6月 6 13:35 /dev/i2c-5
crw-rw---- 1 root i2c 89, 7 6月 6 13:35 /dev/i2c-7
crw-rw---- 1 root i2c 89, 9 6月 6 13:35 /dev/i2c-9
Current user (nvidia) has RW access to all /dev/i2c-* devices.
*** Primary Check 3: Check that module i2c_dev is loaded ***
Checking for driver i2c_dev…
sysfs reports module i2c_dev is NOT loaded.
Module i2c_dev is built into the kernel
*** Primary Check 4: Driver specific checks ***
Performing driver specific checks…
No driver specific checks apply.
*** Additional probes ***
Examining /sys/bus/i2c/devices…
/sys/bus/i2c/devices/4-003c/name: vrs-pseq
/sys/bus/i2c/devices/i2c-0/name: 3160000.i2c
/sys/bus/i2c/devices/i2c-1/name: c240000.i2c
/sys/bus/i2c/devices/i2c-2/name: 3180000.i2c
/sys/bus/i2c/devices/i2c-4/name: Tegra BPMP I2C adapter
/sys/bus/i2c/devices/i2c-5/name: 31b0000.i2c
/sys/bus/i2c/devices/i2c-7/name: c250000.i2c
/sys/bus/i2c/devices/i2c-9/name: i2c-2-mux (chan_id 1)
/sys/bus/i2c/devices/i2c-10/name: i2c-2-mux (chan_id 0)
/sys/bus/i2c/devices/10-0010/name: imx219
/sys/bus/i2c/devices/9-0010/name: imx219
/sys/bus/i2c/devices/i2c-11/name: NVIDIA SOC i2c adapter 0
/sys/bus/i2c/devices/1-0025/name: fusb301
/sys/bus/i2c/devices/1-0040/name: ina3221
/sys/bus/i2c/devices/0-0050/name: 24c02
/sys/bus/i2c/devices/0-0057/name: 24c02
Env_Accumulator:
architecture: aarch64
distributor_id Ubuntu
Drivers detected:
/dev/i2c device numbers: 0 1 2 4 5 7 9 10 11
sysfs_i2c_devices_exist: true
/sys/bus/i2c device numbers: 0 1 2 4 5 7 9 10 11
dev_i2c_devices_required: true
module_i2c_dev_needed: true
module_i2c_dev_builtin: true
loadable_i2c_dev_exists: false
i2c_dev_loaded_or_builtin: true
group_i2c_checked: true
group_i2c_exists: true
dev_i2c_common_group_name: i2c
all_dev_i2c_has_group_i2c: true
any_dev_i2c_has_group_i2c: true
all_dev_i2c_is_group_rw: true
any_dev_i2c_is_group_rw: true
cur_uname: nvidia
cur_uid: 1000
cur_user_in_group_i2c: true
cur_user_any_devi2c_rw: true
cur_user_all_devi2c_rw: true
Configuration suggestions:
Current user has RW access to all /dev/i2c-N devices.
Skipping further group and permission checks.
nvidia@ubuntu:~$