Created attachment 121255 [details] dmesg Attempting to get linux booting on a Vulcan Excursion XB, having issues with i915 (nomodeset / efi graphics work okay). Black screen - with backlight - after i915 is initialised, I've made some dumps of dmesg, etc. everything looks okay besides a backtrace for a suspicious warning: [ 11.122021] WARNING: CPU: 2 PID: 161 at drivers/gpu/drm/drm_irq.c:1271 drm_wait_one_vblank+0x1c4/0x1d0 [drm]() [ 11.122022] vblank wait timed out on crtc 0 Also note the backlight control also seems like it could be busted: [ 8.151269] [drm:pwm_setup_backlight [i915]] *ERROR* Failed to own the pwm chip [ 8.151287] [drm:intel_panel_setup_backlight] failed to setup backlight for connector DSI-1 I also had issues dumping the vbios, no amount of prodding gave me a successful dump (echo 1 > rom; cat rom; echo 0 > rom, nor intel_bios_dumper [the latter of which gives me "Couldn't read graphics card ROM: Input/output error" - I'll try looking at an strace]). Any suggestions there would be appreciated.
Created attachment 121256 [details] regdump
Created attachment 121257 [details] xrandr --verbose - with correct looking panel stats
I can confirm that HDMI works just fine with i915 loaded, so this is definitely something to do with the DSI output to the panel
(In reply to Greg Miell from comment #3) > I can confirm that HDMI works just fine with i915 loaded, so this is > definitely something to do with the DSI output to the panel We seem to have neglected the bug a bit, apologies. Greg Miell, there were improvements pushed in kernel that will benefit to your system, so please re-test with latest kernel and mark as REOPENED if you can reproduce (and attach fresh kernel log) and RESOLVED/* if you cannot reproduce.
I think we've either fixed this in v4.11-rc3 or drm-tip branch of https://cgit.freedesktop.org/drm/drm-tip, *or* this is a dupe of bug 96571. Closing, please don't hesitate to reopen if the problem persists with drm-tip and the kernel config from bug 96571.
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