I can see the boot logo, the grub menu, and first few lines as the kernel loads, then the built-in screen of the tablet goes blank. Backlight is still on, but nothing is on the display. Steps to reproduce the issue: Boot up the tablet without HDMI connected. How often does the steps listed above trigger the issue: Always system architecture: x86_64 kernel version: 4.4.0-rc2-next-20151127+ Linux distribution: Debian Testing Machine or mother board model: Teclast X80h Baytrail tablet Display connector: DSI (built-in display) I have one kernel version (4.3.0-rc5-next-20151012+), which actually works correctly, none of the earlier or later versions I tried works. I attach the dmesg for both working and non-working kernels. I can provide more information if needed.
Created attachment 121156 [details] dmesg of the kernel where screen is working
Created attachment 121157 [details] dmesg of the kernel where screen does not work
Created attachment 121159 [details] xrandr verbose output when screen is working
Created attachment 121160 [details] kernel config of the working kernel
Created attachment 121161 [details] kernel config where the screen does not work
Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel
Created attachment 121245 [details] dmesg of kernel compiled from drm-intel-nightly, built-in display doesn't work I have compiled from intel-nightly-branch as instructed. The built-in display goes blank after drm loads. There is a WARNING in dmesg in all kernels, where the display goes blank, this one is from the dmesg of intel-nightly-branch: [ 6.664456] WARNING: CPU: 3 PID: 58 at drivers/gpu/drm/drm_irq.c:1271 drm_wait_one_vblank+0x13b/0x180 [drm]() [ 6.664457] vblank wait timed out on crtc 0 The full dmesg is attached. Please note that I have a kernel version (linux-next-20151012) where the screen works correctly, you can find the dmesg as the first attachment for this bug, if you wish to compare it.
Tried drm-intel-nightly as instructed. Further information provided.
As I wrote at bug 90469, adding i915.fastboot=1 to the kernel command line enables the DSI display. See the details at bug 90469.
*** This bug has been marked as a duplicate of bug 90469 ***
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