Bug 153181 - [drm:ironlake_crtc_compute_clock [i915]] *ERROR* Couldn't find PLL settings for mode!
Summary: [drm:ironlake_crtc_compute_clock [i915]] *ERROR* Couldn't find PLL settings f...
Status: RESOLVED INVALID
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(Other) (show other bugs)
Hardware: Intel Linux
: P1 normal
Assignee: drivers_video-other
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-08-15 20:58 UTC by Robin Müller
Modified: 2016-08-16 11:59 UTC (History)
2 users (show)

See Also:
Kernel Version: 4.7
Subsystem:
Regression: No
Bisected commit-id:


Attachments
dmesg (53.63 KB, text/plain)
2016-08-15 23:41 UTC, Alexander Kobel
Details
Xorg.log (native modesetting) (9.18 KB, text/plain)
2016-08-15 23:48 UTC, Alexander Kobel
Details

Description Robin Müller 2016-08-15 20:58:10 UTC
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.
Comment 1 Alexander Kobel 2016-08-15 23:41:09 UTC
Confirmed on a Samsung NP900X4C laptop (Intel HD graphics 4000) on Arch Linux. Worked fine in 4.6.5. 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
Comment 2 Alexander Kobel 2016-08-15 23:41:53 UTC
Created attachment 228961 [details]
dmesg
Comment 3 Alexander Kobel 2016-08-15 23:46:29 UTC
The error message is also shown with each virtual console switch. Trying to start X as root locks up my machine (Magic SysRq works, nothing else); as normal user, X fails to start, but leaves me in control otherwise. Attaching Xorg.log too; if you need other logs, let me know.
Comment 4 Alexander Kobel 2016-08-15 23:48:15 UTC
Created attachment 228971 [details]
Xorg.log (native modesetting)
Comment 5 Jani Nikula 2016-08-16 11:35:52 UTC
Please file new drm/i915 bugs at https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel
Comment 6 Alexander Kobel 2016-08-16 11:59:24 UTC
Thanks for the info.

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

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