DDC communication failed - PL2473HD (but works on windows) #570
Description
ddcutil 2.2.0-dev
6.12.57+deb13-amd64
I can't get ddcutil to works on one specific monitor, i get: DDCRC_READ_ALL_ZERO
- same ddcutil works on another monitor
- two other debian13 PCs (1 wayland, 1 xorg, but I don't think it matters) behaves the same, that monitor never works, the other always does
- another windows pc can reliably work with that monitor with many different utilities, here a screenshot of that monitor working on windows:
myuser@debian:~$ ddcutil environment
The following tests probe the runtime environment using multiple overlapping methods.
*** Basic System Information ***
ddcutil version: 2.2.0-dev
/proc/version:
Linux version 6.12.57+deb13-amd64 (debian-kernel@lists.debian.org) (x86_64-linux-gnu-gcc-14 (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44) #1 SMP PREEMPT_DYNAMIC Debian 6.12.57-1 (2025-11-05)
Architecture: x86_64
Distributor id: Debian
Release: 13
Found a known architecture
/proc/cmdline:
BOOT_IMAGE=/boot/vmlinuz-6.12.57+deb13-amd64 root=UUID=2738540b-bff2-4bf3-8f3a-487db99566e4 ro quiet
*** Primary Check 1: Identify video card and driver ***
Obtaining card and driver information from /sys...
Primary video controller at PCI address 0000:00:02.0 (boot_vga flag is set)
Device class: x030000 VGA compatible controller
Vendor: x8086 Intel Corporation
Device: x5a84 Apollo Lake [HD Graphics 505]
Subvendor/Subdevice: 1025/1190 Acer Incorporated [ALI]
Driver name: i915
Driver version: Unable to determine
I2C device: i2c-10 name: i915 gmbus dpc
I2C device: i2c-11 name: i915 gmbus misc
I2C device: i2c-9 name: i915 gmbus dpb
*** Primary Check 2: Check that /dev/i2c-* exist and writable ***
Current user: myuser (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 Jan 4 17:18 /dev/i2c-0
crw-rw---- 1 root i2c 89, 1 Jan 4 17:18 /dev/i2c-1
crw-rw----+ 1 root i2c 89, 10 Jan 4 17:18 /dev/i2c-10
crw-rw----+ 1 root i2c 89, 11 Jan 4 17:18 /dev/i2c-11
crw-rw----+ 1 root i2c 89, 12 Jan 4 17:18 /dev/i2c-12
crw-rw---- 1 root i2c 89, 2 Jan 4 17:18 /dev/i2c-2
crw-rw---- 1 root i2c 89, 3 Jan 4 17:18 /dev/i2c-3
crw-rw---- 1 root i2c 89, 4 Jan 4 17:18 /dev/i2c-4
crw-rw---- 1 root i2c 89, 5 Jan 4 17:18 /dev/i2c-5
crw-rw---- 1 root i2c 89, 6 Jan 4 17:18 /dev/i2c-6
crw-rw---- 1 root i2c 89, 7 Jan 4 17:18 /dev/i2c-7
crw-rw---- 1 root i2c 89, 8 Jan 4 17:18 /dev/i2c-8
crw-rw----+ 1 root i2c 89, 9 Jan 4 17:18 /dev/i2c-9
Current user (myuser) 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 loaded.
Module i2c_dev is NOT built into the kernel
Loadable i2c-dev module found
Module i2c_dev is loaded
*** 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/i2c-ELAN0501:00/name: ELAN0501:00
/sys/bus/i2c/devices/i2c-0/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-1/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-2/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-3/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-4/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-5/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-6/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-7/name: Synopsys DesignWare I2C adapter
/sys/bus/i2c/devices/i2c-8/name: SMBus I801 adapter at 1040
/sys/bus/i2c/devices/i2c-9/name: i915 gmbus dpb
/sys/bus/i2c/devices/i2c-10/name: i915 gmbus dpc
/sys/bus/i2c/devices/i2c-11/name: i915 gmbus misc
/sys/bus/i2c/devices/i2c-12/name: AUX A/DDI A/PHY A
Env_Accumulator:
architecture: x86_64
distributor_id Debian
Drivers detected: i915
/dev/i2c device numbers: 0 1 2 3 4 5 6 7 8 9 10 11 12
sysfs_i2c_devices_exist: true
/sys/bus/i2c device numbers: 0 1 2 3 4 5 6 7 8 9 10 11 12
dev_i2c_devices_required: true
module_i2c_dev_needed: true
module_i2c_dev_builtin: false
loadable_i2c_dev_exists: true
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: myuser
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.
myuser@debian:~$ ddcutil detect --verbose --disable-dynamic-sleep --sleep-multiplier 2
Invalid display
I2C bus: /dev/i2c-10
DRM connector: card0-HDMI-A-1
/sys/class/drm/card0-HDMI-A-1/dpms On
/sys/class/drm/card0-HDMI-A-1/enabled enabled
/sys/class/drm/card0-HDMI-A-1/status connected
/sys/class/drm/card0-HDMI-A-1/connector_id123
Driver: i915
EDID exists: true
I2C address 0x37 (DDC) responsive: true
Is LVDS or EDP display: false
Is laptop display by EDID: false
Is laptop display: false
/sys/bus/i2c/devices/i2c-10/name i915 gmbus dpc
PCI device path: /sys/devices/pci0000:00/0000:00:02.0/i2c-10
EDID synopsis:
Mfg id: IVM - Iiyama North America
Model: PL2473HD
Product code: 24839 (0x6107)
Serial number: 0
Binary serial number: 16843009 (0x01010101)
Manufacture year: 2012, Week: 0
EDID version: 1.3
Extra descriptor:
Video input definition: 0x80 - Digital Input
Supported features:
DPMS active-off
Digital display type: RGB 4:4:4 + YCrCb 4:4:4
Standard sRGB color space: False
White x,y: 0.313, 0.329
Red x,y: 0.641, 0.338
Green x,y: 0.315, 0.629
Blue x,y: 0.159, 0.059
Extension blocks: 1
EDID source: SYSFS
EDID hex dump:
+0 +4 +8 +c 0 4 8 c
+0000 00 ff ff ff ff ff ff 00 26 cd 07 61 01 01 01 01 ........&..a....
+0010 00 16 01 03 80 34 1d 78 2a 2c c5 a4 56 50 a1 28 .....4.x*,..VP.(
+0020 0f 50 54 bf ef 00 b3 00 a9 40 95 00 81 40 81 80 .PT......@...@..
+0030 95 0f 71 4f d1 c0 02 3a 80 18 71 38 2d 40 58 2c ..qO...:..q8-@X,
+0040 45 00 09 25 21 00 00 1e 00 00 00 ff 00 30 0a 20 E..%!........0.
+0050 20 20 20 20 20 20 20 20 20 20 00 00 00 fd 00 37 .....7
+0060 4c 1e 53 11 00 0a 20 20 20 20 20 20 00 00 00 fc L.S... ....
+0070 00 50 4c 32 34 37 33 48 44 0a 20 20 20 20 01 c9 .PL2473HD. ..
DDC communication failed
Failure detail: getvcp of feature x10 returned Error_Info[DDCRC_RETRIES in ddc_write_read_with_retry, causes: DDCRC_READ_ALL_ZERO(10)]
Monitor Model Id: IVM-PL2473HD-24839
Feature definition file IVM-PL2473HD-24839.mccs not found.
myuser@debian:~$ ddcutil detect --verbose --skip-ddc-checks --disable-dynamic-sleep --sleep-multiplier 2 --ddcdata --stats
Display 1
I2C bus: /dev/i2c-10
DRM connector: card0-HDMI-A-1
/sys/class/drm/card0-HDMI-A-1/dpms Off
/sys/class/drm/card0-HDMI-A-1/enabled disabled
/sys/class/drm/card0-HDMI-A-1/status connected
/sys/class/drm/card0-HDMI-A-1/connector_id123
Driver: i915
EDID exists: true
I2C address 0x37 (DDC) responsive: false
Is LVDS or EDP display: false
Is laptop display by EDID: false
Is laptop display: false
/sys/bus/i2c/devices/i2c-10/name i915 gmbus dpc
PCI device path: /sys/devices/pci0000:00/0000:00:02.0/i2c-10
EDID synopsis:
Mfg id: IVM - Iiyama North America
Model: PL2473HD
Product code: 24839 (0x6107)
Serial number: 0
Binary serial number: 16843009 (0x01010101)
Manufacture year: 2012, Week: 0
EDID version: 1.3
Extra descriptor:
Video input definition: 0x80 - Digital Input
Supported features:
DPMS active-off
Digital display type: RGB 4:4:4 + YCrCb 4:4:4
Standard sRGB color space: False
White x,y: 0.313, 0.329
Red x,y: 0.641, 0.338
Green x,y: 0.315, 0.629
Blue x,y: 0.159, 0.059
Extension blocks: 1
EDID source: SYSFS
EDID hex dump:
+0 +4 +8 +c 0 4 8 c
+0000 00 ff ff ff ff ff ff 00 26 cd 07 61 01 01 01 01 ........&..a....
+0010 00 16 01 03 80 34 1d 78 2a 2c c5 a4 56 50 a1 28 .....4.x*,..VP.(
+0020 0f 50 54 bf ef 00 b3 00 a9 40 95 00 81 40 81 80 .PT......@...@..
+0030 95 0f 71 4f d1 c0 02 3a 80 18 71 38 2d 40 58 2c ..qO...:..q8-@X,
+0040 45 00 09 25 21 00 00 1e 00 00 00 ff 00 30 0a 20 E..%!........0.
+0050 20 20 20 20 20 20 20 20 20 20 00 00 00 fd 00 37 .....7
+0060 4c 1e 53 11 00 0a 20 20 20 20 20 20 00 00 00 fc L.S... ....
+0070 00 50 4c 32 34 37 33 48 44 0a 20 20 20 20 01 c9 .PL2473HD. ..
VCP version: Detection failed
DDC: All zero response detected in ddc_i2c_write_read_raw
(get_controller_mfg_string_t) Freeing exception:
Exception in function i2c_check_open_bus_alive: status=DDCRC_DPMS_ASLEEP(-3030): display is in a DPMS sleep mode
/dev/i2c-10
Controller mfg: DDC communication failed
DDC: Unexpected source address 0x00, should be 0x6e
DDC: i2c_response_bytes: 00 00 80 9e be ae 6e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
DDC: All zero response detected in ddc_i2c_write_read_raw
Exception in function ddc_write_read_with_retry: status=DDCRC_RETRIES(-3007): maximum retries exceeded
Caused by:
Exception in function ddc_write_read: status=DDCRC_DDC_DATA(-3001): DDC data error
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Exception in function ddc_write_read: status=DDCRC_READ_ALL_ZERO(-3006): packet contents entirely 0x00
Firmware version: DDC communication failed
Monitor uses invalid feature flag in DDC reply packet to indicate unsupported feature.
Monitor Model Id: IVM-PL2473HD-24839
Feature definition file IVM-PL2473HD-24839.mccs not found.
##########################################################################
####### I removed my laptop display data to shorten the text wall ########
##########################################################################
EXECUTION STATISTICS
Maxtries Settings:
Operation Type Current Default Min Max
Write only exchange tries: 4 4 4 4
Write read exchange tries: 10 4 10 10
Multi-part read exchange tries: 8 4 8 8
Multi-part_write exchange tries: 8 4 8 8
Retry statistics for write only
No tries attempted
Retry statistics for write-read
Max tries allowed: 10
Successful attempts by number of tries required: None
Total successful attempts: 0
Failed due to max tries exceeded: 3
Failed due to fatal error: 0
Total attempts: 3
Retry statistics for multi-part read
No tries attempted
Retry statistics for multi-part write
No tries attempted
DDC Related Errors:
Count Status Code Description
1 ENXIO ( -6) No such device or address
20 EREMOTEIO ( -121) Remote I/O error
1 DDCRC_DDC_DATA (-3001) DDC data error
10 DDCRC_READ_ALL_ZERO (-3006) packet contents entirely 0x00
3 DDCRC_RETRIES (-3007) maximum retries exceeded (derived)
Total errors: 35
Errors Wrapped in Retry:
Count Status Code Description
1 ENXIO ( -6) No such device or address
20 EREMOTEIO ( -121) Remote I/O error
1 DDCRC_DDC_DATA (-3001) DDC data error
10 DDCRC_READ_ALL_ZERO (-3006) packet contents entirely 0x00
Total errors: 32
IO and Sleep Events:
Total IO events: 74
IO error count: 35
Total sleep events: 24
Sleep Event type Count
SE_WRITE_TO_READ 12
SE_POST_WRITE 0
SE_POST_READ 12
SE_POST_SAVE_SETTINGS 0
SE_PRE_MULTI_PART_READ 0
SE_POST_CAP_TABLE_SEGMENT 0
SE_SPECIAL 0
Call Stats:
Type Count Millisec ( Nanosec)
i2c writes using ioctl (I2_IOCTL_WRITE) 43 569 ( 569350883)
i2c reads using ioctl (I2_IOCTL_READ) 19 60 ( 60552756)
open file calls (IE_OPEN) 6 0 ( 86783)
close file calls (IE_CLOSE) 6 0 ( 78148)
Totals: 74 630 ( 630068570)
Sleep Call Stats:
Total sleep calls: 24
Requested sleep time milliseconds : 2400
Actual sleep milliseconds (nanosec): 2408 ( 2408807738)
Total elapsed milliseconds (nanoseconds): 6492 ( 6492087676)
Total non sleep system call time: 630 milliseconds
Total sleep call time: 2408 milliseconds
Elapsed time: 6492 milliseconds
Any idea? Thanks.