7" Display Kit - Linux Kernel complains that EDID checksum is invalid

bechir

When I connect my 7" display kit to the UP2 (IAE3940) board, I can see the UEFI splash screen, grub menu, but once Linux kernel start loading, the screen turns black.

However, I do not have this issue if I connect the 10" Display kit.

On the Kernel logs, I can see that Linux is complaining that EDID checksum is invalid.
Here is the logs

[ 0.000000] Linux version 4.9.45-ubilinux+ (javier@build-debian) (gcc version 4.9.2 (Debian 4.9.2-10) ) #1 SMP Tue Aug 29 11:41:15 IST 2017
[ 0.000000] efi: EFI v2.50 by American Megatrends
[ 0.000000] efi: ACPI=0x79c1a000 ACPI 2.0=0x79c1a000 SMBIOS=0x79edf000 SMBIOS 3.0=0x79ede000
[ 0.000000] SMBIOS 3.0.0 present.
[ 4.061720] [drm] Finished loading i915/bxt_dmc_ver1_07.bin (v1.7)
[ 4.085097] [drm:drm_edid_block_valid [drm]] ERROR EDID checksum is invalid, remainder is 247
[ 4.159255] [drm:drm_edid_block_valid [drm]] ERROR EDID checksum is invalid, remainder is 129
[ 4.230152] [drm:drm_edid_block_valid [drm]] ERROR EDID checksum is invalid, remainder is 143
[ 4.279524] [drm:drm_edid_block_valid [drm]] ERROR EDID checksum is invalid, remainder is 130
[ 4.279539] i915 0000:00:02.0: eDP-1: EDID block 0 invalid.
[ 4.298548] [drm] GuC firmware load skipped

Any idea ?

jan77

My setup:
UP2 - BIOS V3.3
dude@up2:~$ uname -a Linux up2 4.9.45-ubilinux+ #2 SMP Fri Sep 8 10:51:36 IST 2017 x86_64 GNU/Linux
I have disabled the X session by doing:
systemctl disable sddm.service

I have a similar problem. EDID is read, but only on some boots. When I'm lucky, I can see the supported modes (through ssh):
dude@up2:~$ cat /sys/class/drm/card0-eDP-1/modes 1024x600 800x600 800x600 800x600 640x480 720x400

I always end up with black screen after the kernel mode setting kicks in.
Those are regular errors I get on boot, when trying to use the above mentioned 7" display:
[ 2349.713815] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.719375] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.724933] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.730482] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.736036] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.741593] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.747146] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.752705] [drm:intel_dp_aux_ch [i915]] *ERROR* dp_aux_ch receive error status 0x6e1003ff
[ 2349.752735] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to start channel equalization

Sometimes I see the errors mentioned above (about EDID invalid checksum).

If I add nomodeset as a boot parameter, I can boot into a console (on the display). But I need kms in order to run embedded Qt5 application.

Anybody any suggestions?

Kind regards,
Jan

nyceane

I am having same problem, as the up2 BIOS simply does not support 1024x600

I am asking support on whether I can get a replacement since it does not work... The website clearly states that it supports upsquared board but the screen simply does not work.