Bug 101168 - [i915][SKL] Kernel ignoring custom modeline - cannot set monitors full resolution
Summary: [i915][SKL] Kernel ignoring custom modeline - cannot set monitors full resolu...
Status: CLOSED NOTABUG
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard: ReadyForDev
Keywords:
Depends on:
Blocks:
 
Reported: 2017-05-24 17:39 UTC by Norbert Varzariu
Modified: 2017-06-30 21:35 UTC (History)
1 user (show)

See Also:
i915 platform: SKL
i915 features: display/Other


Attachments
dmesg with drm.debug=0x1e log_buf_len=1M (1005.29 KB, text/plain)
2017-05-24 17:39 UTC, Norbert Varzariu
no flags Details
dmesg with drm.debug=0x1e log_buf_len=5M (611.10 KB, text/plain)
2017-05-26 05:22 UTC, Norbert Varzariu
no flags Details
dmesg of 4.11.6 (273.33 KB, text/plain)
2017-06-28 19:30 UTC, Norbert Varzariu
no flags Details
Xorg log (61.77 KB, text/x-log)
2017-06-28 19:31 UTC, Norbert Varzariu
no flags Details

Description Norbert Varzariu 2017-05-24 17:39:10 UTC
Created attachment 131470 [details]
dmesg with drm.debug=0x1e log_buf_len=1M

Hi.

Ever since I upgraded to kernels >4.11, I'm unable to set the maximum supported resolution. I have a WQHD monitor with a resolution of 2560x1440. With kernels prior to 4.11 it would pick up my custom modeline I configured in /etc/X11/xorg.conf.d and show full resolution. With newer kernels max supported resolution seems to be only 2048x1152.

How often:
Every time

uname -rm:
4.11.2 x86_64

Distro:
Fedora

Motherboard:
MSI Z170A PC MATE

Display connector:
HDMI (via a DVI-D to HDMI adapter)

Dmesg attached. Please let me know if I can provide any further assistance.
Comment 1 Norbert Varzariu 2017-05-26 05:21:50 UTC
I noticed the dmesg wasn't complete, so I attached a new one.
Comment 2 Norbert Varzariu 2017-05-26 05:22:19 UTC
Created attachment 131521 [details]
dmesg with drm.debug=0x1e log_buf_len=5M
Comment 3 Ville Syrjala 2017-05-27 17:16:28 UTC
(In reply to Norbert Varzariu from comment #2)
> Created attachment 131521 [details]
> dmesg with drm.debug=0x1e log_buf_len=5M

There are no 2560x1440 modesets visible in that log. So this seems to be a userspace configuration issue.

Can you try to just add the modeline manually?
xrandr --newmode <name> ...
xrandr --addmode <output> <name>
xrandr --output <output> --mode <name>
Comment 4 Norbert Varzariu 2017-05-28 03:22:57 UTC
(In reply to Ville Syrjala from comment #3)
> (In reply to Norbert Varzariu from comment #2)
> > Created attachment 131521 [details]
> > dmesg with drm.debug=0x1e log_buf_len=5M
> 
> There are no 2560x1440 modesets visible in that log. So this seems to be a
> userspace configuration issue.
> 
> Can you try to just add the modeline manually?
> xrandr --newmode <name> ...
> xrandr --addmode <output> <name>
> xrandr --output <output> --mode <name>

Hi. This is indeed a setting in xorg.conf, however, this part in the dmesg is new:

[    2.073595] [drm:drm_mode_debug_printmodeline [drm]] Modeline 63:"2560x1440" 60 241500 2560 2608 2640 2720 1440 1443 1448 1481 0x48 0x9
[    2.073600] [drm:drm_mode_prune_invalid [drm]] Not using 2560x1440 mode: CLOCK_HIGH

It seems to try and validate my modeline but discard it as invalid. 

I will try and use xrandr right away.
Comment 5 Norbert Varzariu 2017-05-28 03:28:39 UTC
Ok, using xrandr for adding my modeline works. How can I make this reboot persistent like it was before?
Comment 6 Norbert Varzariu 2017-06-28 19:22:47 UTC
It's getting worse. 

With kernels >4.11.5 I don't have an xsession at all anymore. After the bootup process, when the screen turns black, usually I see my login window. But for newer kernels it just drops back into tty. Although my mouse pointer is rendered on the primary screen.

So basically I'm stuck at 4.10 if I want a working kernel...
Comment 7 Norbert Varzariu 2017-06-28 19:30:29 UTC
Created attachment 132309 [details]
dmesg of 4.11.6
Comment 8 Norbert Varzariu 2017-06-28 19:31:34 UTC
Created attachment 132310 [details]
Xorg log

Here's an Xorg log I got when trying to startx manually.
Comment 9 Ville Syrjala 2017-06-28 19:51:36 UTC
The modelines you're trying to use exceed the capabilities of the poor SKL.

[   16.182265] [drm:intel_hdmi_compute_config [i915]] unsupported HDMI clock, rejecting mode
[   16.182532] [drm:drm_mode_debug_printmodeline [drm]] Modeline 0:"" 0 312250 2560 2752 3024 3488 1440 1443 1448 1493 0x0 0x6

The maximum dotclock you can use is 300 MHz, whereas this mode is ~312 MHz.

You should try the mode that the display reports in its EDID:
241.5 2560 2608 2640 2720 1440 1443 1448 1481 +hsync -vsync
Comment 10 Norbert Varzariu 2017-06-28 19:58:00 UTC
Awesome, this fixed it. Thank you very much!


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