[Bug 97363] New: [drm:ironlake_crtc_compute_clock [i915]] *ERROR* Couldn't find PLL settings for mode!

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97363

            Bug ID: 97363
           Summary: [drm:ironlake_crtc_compute_clock [i915]] *ERROR*
                    Couldn't find PLL settings for mode!
           Product: DRI
           Version: unspecified
          Hardware: x86-64 (AMD64)
                OS: Linux (All)
            Status: NEW
          Severity: major
          Priority: medium
         Component: DRM/Intel
          Assignee: intel-gfx-bugs at lists.freedesktop.org
          Reporter: a-kobel at a-kobel.de
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
                CC: intel-gfx-bugs at lists.freedesktop.org

Created attachment 125813
  --> https://bugs.freedesktop.org/attachment.cgi?id=125813&action=edit
Xorg.log

This is a followup on https://bugzilla.kernel.org/show_bug.cgi?id=153181, where
we were redirected to here.
Robin reports:

After upgrading to linux-4.7 I get the following error during boot time and
while starting Wayland or xserver (ends in a black screen):

[drm:ironlake_crtc_compute_clock [i915]] *ERROR* Couldn't find PLL settings for
mode!

I'm not sure if this is the cause for the error but I had a look to the changes
of the intel_driver.c between 4.6 and 4.7 and noticed the following:
With linux-4.6 the method ironlake_crtc_compute_clock used
ironlake_compute_clocks for retrieving the PLL settings. Which then used on of
the following methods depending on the given device:
- g4x_find_best_dpll
- chv_find_best_dpll
- vlv_find_best_dpll
- pnv_find_best_dpll
- i9xx_find_best_dpll
In linux-4.7 the method ironlake_crtc_compute_clock uses only this one
g4x_find_best_dpll.


I confirm on a Samsung NP900X4C laptop (Intel HD graphics 4000) on Arch Linux.
Worked fine in 4.6.5. Booting to the console already prints the message a
number of times. When trying to start X as root, the system freezes entirely
(only Magic SysRq to the rescue); as user, X fails to start, but the system
stays responsive. The error message from the title also appears whenever I
switch virtual terminals.

A discussion with some (unsuccessful) hints is here:
https://bbs.archlinux.org/viewtopic.php?id=215847
Things that didn't work:
- uninstall xf86-video-intel and use the native modesetting
- add iomem=relaxed as a kernel parameter

I attach the dmesg output as well as an Xorg.log. The btrfs complaints are
unrelated and due to the fact that I had to shut down the system hard.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20160816/27a621a4/attachment.html>