F36 x11 cannot connect second monitor

fedora35/kde on an old macbook pro with i5-2435m and 3000hd graphics.

i’m trying to connect a tv as a second monitor via mini-dp to hdmi cable, but the tv shows no signal and the display settings in kde does not detect any monitor.

i don’t know what to look for exactly, but with generic googling i managed to find out that some people with similar problem have driver problems, specifically with nvidia, so nothing for me here, but here’s the inxi -G command anyway, it shows as follows:

Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
    driver: i915 v: kernel
  Device-2: Apple FaceTime HD Camera type: USB driver: uvcvideo
  Display: x11 server: X.Org v: 1.20.14 with: Xwayland v: 22.1.3 driver: X:
    loaded: modesetting unloaded: fbdev,vesa gpu: i915 resolution: 1280x800
  OpenGL: renderer: Mesa Intel HD Graphics 3000 (SNB GT2) v: 3.3 Mesa
    22.1.7

inxi -Fzx:

System:
  Kernel: 5.19.11-200.fc36.x86_64 arch: x86_64 bits: 64 compiler: gcc
    v: 2.37-36.fc36 Desktop: KDE Plasma v: 5.25.5 Distro: Fedora release 36
    (Thirty Six)
Machine:
  Type: Laptop System: Apple product: MacBookPro8,1 v: 1.0
    serial: <superuser required>
  Mobo: Apple model: Mac-94245B3640C91C81 v: MacBookPro8,1
    serial: <superuser required> UEFI: Apple v: 87.0.0.0.0 date: 06/13/2019
Battery:
  ID-1: BAT0 charge: 38.7 Wh (71.0%) condition: 54.5/62.9 Wh (86.7%)
    volts: 11.5 min: 10.9 model: SMP bq20z451 status: discharging
  Device-1: hidpp_battery_0 model: Logitech M570 charge: 95%
    status: discharging
CPU:
  Info: dual core model: Intel Core i5-2435M bits: 64 type: MT MCP
    arch: Sandy Bridge rev: 7 cache: L1: 128 KiB L2: 512 KiB L3: 3 MiB
  Speed (MHz): avg: 874 high: 1098 min/max: 800/3000 cores: 1: 800 2: 1098
    3: 800 4: 798 bogomips: 19157
  Flags: avx ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
    vendor: Apple driver: i915 v: kernel arch: Gen-6 bus-ID: 00:02.0
  Device-2: Apple FaceTime HD Camera type: USB driver: uvcvideo
    bus-ID: 1-2:3
  Display: x11 server: X.Org v: 1.20.14 with: Xwayland v: 22.1.3 driver: X:
    loaded: modesetting unloaded: fbdev,vesa gpu: i915 resolution: 1280x800
  OpenGL: renderer: Mesa Intel HD Graphics 3000 (SNB GT2) v: 3.3 Mesa
    22.1.7 direct render: Yes
Audio:
  Device-1: Intel 6 Series/C200 Series Family High Definition Audio
    driver: snd_hda_intel v: kernel bus-ID: 00:1b.0
  Sound Server-1: ALSA v: k5.19.11-200.fc36.x86_64 running: yes
  Sound Server-2: PulseAudio v: 15.0 running: no
  Sound Server-3: PipeWire v: 0.3.58 running: yes
Network:
  Device-1: Broadcom NetXtreme BCM57765 Gigabit Ethernet PCIe driver: tg3
    v: kernel port: N/A bus-ID: 02:00.0
  IF: enp2s0f0 state: down mac: <filter>
  Device-2: Broadcom BCM4331 802.11a/b/g/n vendor: Apple AirPort Extreme
    driver: wl v: kernel bus-ID: 03:00.0
  IF: wlp3s0 state: up mac: <filter>
Bluetooth:
  Device-1: Apple Bluetooth Host Controller type: USB driver: btusb v: 0.8
    bus-ID: 1-1.1.3:9
  Report: rfkill ID: hci0 rfk-id: 1 state: down bt-service: enabled,running
    rfk-block: hardware: no software: yes address: see --recommends
Drives:
  Local Storage: total: 476.94 GiB used: 23.29 GiB (4.9%)
  ID-1: /dev/sda vendor: Intel model: SSDSC2KW512G8 size: 476.94 GiB
Partition:
  ID-1: / size: 475.14 GiB used: 23 GiB (4.8%) fs: btrfs dev: /dev/dm-0
    mapped: luks-c834abe5-adab-40a2-9b2b-1061b36e296e
  ID-2: /boot size: 973.4 MiB used: 272.1 MiB (28.0%) fs: ext4
    dev: /dev/sda3
  ID-3: /boot/efi size: 600 MiB used: 30.5 MiB (5.1%) fs: hfsplus
    dev: /dev/sda2
  ID-4: /home size: 475.14 GiB used: 23 GiB (4.8%) fs: btrfs dev: /dev/dm-0
    mapped: luks-c834abe5-adab-40a2-9b2b-1061b36e296e
Swap:
  ID-1: swap-1 type: zram size: 3.74 GiB used: 463.8 MiB (12.1%)
    dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 67.0 C mobo: 0.0 C
  Fan Speeds (RPM): N/A
Info:
  Processes: 285 Uptime: 55m Memory: 3.74 GiB used: 2.26 GiB (60.3%)
  Init: systemd target: graphical (5) Compilers: gcc: 12.2.1 Packages: 25
  note: see --rpm Shell: Bash v: 5.1.16 inxi: 3.3.21

With the monitor already connected and powered on, reboot.

Then repeat the inxi -Fzxxx command to see if there is a difference. (note I added extra there for a more verbose output)
Look at the output of dmesg to see if it may tell you anything about the dp connection.
Also look at /var/log/Xorg.0.log and similar to see what they may tell you about the graphics.
You may not get anything extra since you are using the integrated GPU which often does not return much detail.

On most systems as long as the GPU is properly activated then all its ports are also active.

inxi returns this, so the only thing i can digest from it is there is indeed no output, though i’m not sure what are the 1s, 2s and 3s for dp and hdmi since there’s only one dp at least ot the outside.

Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
    vendor: Apple driver: i915 v: kernel arch: Gen-6 ports: active: LVDS-1
    empty: DP-1, DP-2, DP-3, HDMI-A-1, HDMI-A-2, HDMI-A-3, VGA-1
    bus-ID: 00:02.0 chip-ID: 8086:0126 class-ID: 0300
  Device-2: Apple FaceTime HD Camera type: USB driver: uvcvideo
    bus-ID: 1-2:3 chip-ID: 05ac:8509 class-ID: 0e02 serial: <filter>
  Display: x11 server: X.Org v: 1.20.14 with: Xwayland v: 22.1.3
    compositor: kwin_x11 driver: X: loaded: modesetting unloaded: fbdev,vesa
    gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 1280x800 s-dpi: 96 s-size: 338x211mm (13.31x8.31")
    s-diag: 398mm (15.69")
  Monitor-1: LVDS-1 model: Apple Color LCD res: 1280x800 dpi: 114
    size: 286x178mm (11.26x7.01") diag: 347mm (13.6") modes: 1280x800
  OpenGL: renderer: Mesa Intel HD Graphics 3000 (SNB GT2) v: 3.3 Mesa
    22.1.7 direct render: Yes

the part i find relatively relevant from dmesg is this:

[    3.598546] i915 0000:00:02.0: vgaarb: deactivate vga console
[    3.680674] [drm] Initialized i915 1.6.0 20201103 for 0000:00:02.0 on minor 1
[    3.682073] ACPI: video: Video Device [IGPU] (multi-head: yes  rom: no  post: no)
[    3.682589] acpi device:10: registered as cooling_device4
[    3.682684] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:01/input/input18
[    3.930117] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[    3.930124]  [00] BAD  00 ff ff ff ff ff ff 00 ff ff ff ff ff ff ff ff
[    3.930126]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930128]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930129]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930130]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930132]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930133]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.930135]  [00] BAD  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[    3.932898] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[    4.014271] fbcon: i915drmfb (fb0) is primary device
[    4.014274] fbcon: Deferring console take-over
[    4.014277] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
[    4.027263] random: crng init done
[    4.259228] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[    4.262251] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[    5.479940] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[    5.482893] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[    5.909875] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[    5.912861] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20

firstly, because the edid part looks familiar - i used to extracting these edid blocks for my other tv i use as a monitor to edit registry on windows to solve some very specific coloring problem. secondly, because this error message keep coming up:

[   33.494157] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[   33.812859] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[   33.816256] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[   37.060059] Bluetooth: RFCOMM TTY layer initialized
[   37.060069] Bluetooth: RFCOMM socket layer initialized
[   37.060145] Bluetooth: RFCOMM ver 1.11
[   45.159109] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[   45.162029] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[   46.209301] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[   46.212262] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[   47.216444] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
[   47.922647] IPv6: ADDRCONF(NETDEV_CHANGE): wlp3s0: link becomes ready
[   50.679909] logitech-hidpp-device 0003:046D:1028.0009: HID++ 1.0 device connected.
[  128.844774] EDID block 0 (tag 0x00) checksum is invalid, remainder is 125
[  128.847760] i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20

though what to make of it idk. i do use a brand new generic miniDP-to-hdmi adaptor, but i’m not sure it is what those error messages mean.

as for the log file, again, as far as i can tell, it only tells it detects the onboard monitor:

[    33.658] (II) modeset(0): EDID for output VGA-1
[    33.814] (II) modeset(0): EDID for output HDMI-1
[    33.893] (II) modeset(0): EDID for output DP-1
[    33.895] (II) modeset(0): EDID for output HDMI-2
[    33.896] (II) modeset(0): EDID for output HDMI-3
[    33.896] (II) modeset(0): EDID for output DP-2
[    33.896] (II) modeset(0): EDID for output DP-3
[    33.896] (II) modeset(0): Output LVDS-1 connected
[    33.896] (II) modeset(0): Output VGA-1 disconnected
[    33.896] (II) modeset(0): Output HDMI-1 disconnected
[    33.896] (II) modeset(0): Output DP-1 disconnected
[    33.896] (II) modeset(0): Output HDMI-2 disconnected
[    33.896] (II) modeset(0): Output HDMI-3 disconnected
[    33.896] (II) modeset(0): Output DP-2 disconnected
[    33.896] (II) modeset(0): Output DP-3 disconnected
[    33.896] (II) modeset(0): Using exact sizes for initial modes
[    33.896] (II) modeset(0): Output LVDS-1 using initial mode 1280x800 +0+0

ps: the error message surprisingly googles pretty effectively.

interresting. i’ve found a guy on the internet with very similar setup and problem - old intel laptop, i915 driver or whatever, the same error message and faulty monitor connection (though less consistent than in my case). and in his case it occurs only on x11, but not on wayland, and most importantly the issue seems to be with synology drive applet (it running prevents proper monitor detection and or setup and if it’s run after the monitor plugin it actually triggers the problem). the consensus is it somehow affects the kernel i believe (he gets this with different hdmi cables so there’s that).

the thing is i don’t use synology in any form, but this might suggest that some other app in my system does the same for me.

ps: the semisolution that seems to work for the person there is

One thing you may want to try is slow down the i2c bus further. We use 100kHz by default, and you may want to try something like 10kHz instead.

--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -127,7 +127,7 @@ bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,

 /* Intel GPIO access functions */

-#define I2C_RISEFALL_TIME 10
+#define I2C_RISEFALL_TIME 100

but i don’t understand what it is so i don’t know how to test it on my system.

found this:

It has some problem when user connect to external 4K monitor with refresh rate 60.
The problem can be solved by lower the bpc, or lower the refresh rate.

xrandr --output DP-3 --set "max bpc" 8

it’s kind of similar to my situation - i am trying to connect a 4k@60hz tv with working but pretty old hmdi cable and a dp-hdmi adaptor of unknown quality (though the monitor working at 1080p@60 instead of 4k is fine by me, just let me set it up). the idea is that something may be limiting bandwidth, which prevents the monitor detection. unfortunately neither bpc 8 nor bpc 6 helps in my case.

ps: i’m experimenting with different xrandr commands rn and can not get some of them working. for example i can set --rate to lower number, but can’t get --mode set up to anything (neither 1920x1080 nor 1280x800 or x720):

xrandr: cannot find mode 1280x800

well, long story short, switched to w10, still had no luck, but while doing the installation i’ve found an (original apple?) minidp-hdmi cable, that however didn’t work in windows. then i switched back to fedora and it - the newly found out cable that is - did indeed work! and my dp-hdmi+hdmi-hdmi did not still. so i guess i have to admit the cable or the dongle was the issue.

or could it be that the clear install resolved something on fedora side?