Bug 89996 - Provided resolutions use incorrect aspect ratio
Summary: Provided resolutions use incorrect aspect ratio
Status: NEW
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: git
Hardware: x86-64 (AMD64) All
: medium normal
Assignee: Chris Wilson
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-04-12 22:02 UTC by Michael Cronenworth
Modified: 2015-04-14 21:27 UTC (History)
2 users (show)

See Also:
i915 platform:
i915 features:


Attachments
Intel Video ROM and Xorg log (4.77 KB, application/x-gtar)
2015-04-12 22:02 UTC, Michael Cronenworth
no flags Details

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Description Michael Cronenworth 2015-04-12 22:02:24 UTC
Created attachment 115040 [details]
Intel Video ROM and Xorg log

Screen: native 2560x1440, 16:9
GPU: Core i7 4558U, Iris 5100, Haswell GT3
The attached Xorg log will show I'm using kernel 4.0 and the latest intel Xorg driver. This same issue occurs with older kernels and older intel driver versions.

Windows: All resolutions are available for all aspect ratios. Example, I can set 1920x1080 without a problem.

Linux: Only the native resolution is provided for 16:9. The other resolutions available are for 4:3 or 5:4.

$ xrandr 
Screen 0: minimum 8 x 8, current 2560 x 1440, maximum 32767 x 32767
eDP1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 294mm x 165mm
   2560x1440     59.95*+
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   1600x1200     60.00  
   1400x1050     59.98  
   1280x1024     60.02  
   1280x960      60.00  
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Other users of different laptops are reporting the same issue: https://bugzilla.redhat.com/show_bug.cgi?id=1211058
Comment 1 Chris Wilson 2015-04-12 22:07:09 UTC
They aren't probed, they are fake modes. What is the actual bug here?
Comment 2 Michael Cronenworth 2015-04-13 00:19:44 UTC
Are we expected to provide manual mode lines on a 16:9 screen to get 16:9 resolutions?
Comment 3 Russel Winder 2015-04-13 07:06:04 UTC
As previously noted here:  https://bugzilla.redhat.com/show_bug.cgi?id=1211058

With Debian Sid I get all the relevant resolutions listed in GNOME, whereas in Fedora Rawhide the 16:10 and 16:9 resolutions other than the screen native one are missing from the available list. So in particular I can get 1080p in Debian Sid but not in Fedora Rawhide.

The question is therefore what has changed between the current Debian Sid, which is quite old now, and the current Fedora Rawhide, which is far more up to date, such that I am unable to get Xorg to do the thing that used to be possible.
Comment 4 Chris Wilson 2015-04-14 20:03:51 UTC
commit 26fd6bec113194c471c5d9e1b414c0a1824c5a23
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 14 20:47:26 2015 +0100

    sna: Add common widescreen resolutions
    
    Currently we add fake modes to cater for applications that want to
    change the screen size but limit themselves to only those that are
    available, and do not wish to either use RandR scaling or their own. For
    widescreen panels, these 4:3 aspect ratio modes require panel fitting
    and so are less than satisfory. Since we add fake modes, let's add a few
    common widescreen modes as well (choosing the right aspect ration for
    the panel).
    
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=37858
    References: https://bugs.freedesktop.org/show_bug.cgi?id=29890
    References: https://bugs.freedesktop.org/show_bug.cgi?id=89996
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

This doesn't explain the difference between Debian and Fedora, but it should add the extra fake modes automatically for you.
Comment 5 Michael Cronenworth 2015-04-14 20:46:40 UTC
Thanks for the quick patch, Chris. I tried it out, but the only added mode was for 1280x720.

$ xrandr
Screen 0: minimum 8 x 8, current 2560 x 1440, maximum 32767 x 32767
eDP1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 294mm x 165mm
   2560x1440     59.95*+
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   1600x1200     60.00  
   1400x1050     59.98  
   1280x1024     60.02  
   1280x960      60.00  
   1280x720      60.00  
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
Comment 6 Chris Wilson 2015-04-14 21:05:46 UTC
Oops, an embarrassing mistake:

commit 2faf255100331ae17dbc5f9072edb4fd9dd68773
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 14 22:01:22 2015 +0100

    sna: Reverse the size check so that it works
Comment 7 Michael Cronenworth 2015-04-14 21:27:01 UTC
Thanks. I wasn't going to say anything ;) The mode list is happily populated now.


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