[drm:drm_atomic_check_only [drm]] atomic driver check for 000000002450ad2f failed: -22
Hardware
My setup consists of a Lenovo Thinkpad T420 laptop connected to a Lenovo 4338 docking station with two external Dell U2515H monitors connected via DisplayPort. I'm booting the laptop docked, with the lid closed and both external monitors powered on. The laptop is running Coreboot bios, which enabled me to upgrade the laptop with an Ivy Bridge cpu.
I had some doubts whether to write this bug report or not, as I'm not sure whether my setup is supported at all. If not, please feel free to close this bug report as such.
Bug description
Graphic initialization fails during boot when both my external DisplayPort monitors are powered on. If I turn one off, the situation sorts itself out and a luks key prompt appears on the other one. Once the boot process has reached my desktop environment, I can power on the other monitor again, and both will work fine.
I'm running Debian 10 and can reproduce this issue with both the stock kernel (4.19) as well as the one in experimental (5.5.0-rc5).
Logs
Attached you'll find my kernel log with 5.5.0-rc5 booted with drm.debug=0x1e log_buf_len=4M
- Graphic initialization fails during boot with this error:
[ 3.529068] [drm:drm_atomic_check_only [drm]] atomic driver check for 000000002450ad2f failed: -22
- I turn off one monitor a bit later, after which I can use the other one to continue boot. See log starting from:
[ 76.047658] [drm:ibx_hpd_irq_handler [i915]] hotplug event received, stat 0x00400000, dig 0x00101210, pins 0x00000040, long 0x00000040
- Then once I'm in my desktop environment, I turn on the other monitor again and I can use both fine now. See log starting from:
[ 155.505622] [drm:ibx_hpd_irq_handler [i915]] hotplug event received, stat 0x00400000, dig 0x00101210, pins 0x00000040, long 0x00000040
Is the first error a bug i.e. resolvable, since the setup works ultimately?