My Dell Latitude E7450 crashes with gentoo 4.15.9 kernel directly after boot. This happens only when the laptop is in the docking station. When undocked, the machine is booting fine, but also crashes as soon as I put it in the docking station. Kernel 4.9.76-r1 is working without problems. log messages: Mär 14 12:12:55 etkbox kernel: [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun Mär 14 12:12:55 etkbox kernel: [drm:pipe_config_err] *ERROR* mismatch in pixel_rate (expected 148500, found 247499) Mär 14 12:12:55 etkbox kernel: [drm:pipe_config_err] *ERROR* mismatch in shared_dpll (expected 00000000cac9ad22, found 00000000f93ec4c3) Mär 14 12:12:55 etkbox kernel: [drm:pipe_config_err] *ERROR* mismatch in base.adjusted_mode.crtc_clock (expected 148500, found 247499) Mär 14 12:12:55 etkbox kernel: [drm:pipe_config_err] *ERROR* mismatch in port_clock (expected 162000, found 270000) Mär 14 12:12:55 etkbox kernel: ------------[ cut here ]------------ Mär 14 12:12:55 etkbox kernel: pipe state doesn't match! Mär 14 12:12:55 etkbox kernel: WARNING: CPU: 1 PID: 2723 at drivers/gpu/drm/i915/intel_display.c:11601 intel_atomic_commit_tail+0xb85/0xc90 Full log attached. This is probably the same bug that is described here: https://bugzilla.redhat.com/show_bug.cgi?id=1549042 Reproducible: Always Steps to Reproduce: 1. booting up when docked or put the running machine in the docking station Actual Results: System crashes and has to be rebooted.
Created attachment 523996 [details] syslog
Created attachment 523998 [details] lspci
Hi, Have you the same problem with 4.15.13 ? Thanks
Created attachment 526038 [details] log with drm.debug=0xe Problem still there in kernel 4.15.13. New log attached with drm.debug=0xe set.
Created attachment 526042 [details, diff] drm-i915-dp-Write-to-SET_POWER-dpcd-to-enable-MST-hub-gentoo.patch I tried the patch from https://patchwork.freedesktop.org/patch/210500/ and it fixes my problem. Had to manually fix the patch for my kernel. New patch attached.
Maybe similar bug: https://bugs.gentoo.org/649298 Kernel hangs on boot.
Created attachment 526140 [details, diff] backported i915 patch from Linus' tree I had to tweak the patch to apply to 4.15? Did you do the same? Can you test this one against 4.15. You can apply with: patch -p1 < /location/of/2700_i915-to-SET-POWER-dpcd-to-enable-MST-hub.patch
Your patch is the same as mine, only difference is the deleted comment. I also had to tweak it in order to work.
4.15 is EOL'ed and the upstream patch is in kernels >= 4.16.
