Nouveau - Aug 2008 - [Bug 16952] New: Bad video modes

http://bugs.freedesktop.org/show_bug.cgi?id=16952

           Summary: Bad video modes
           Product: xorg
           Version: git
          Platform: x86-64 (AMD64)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Driver/nouveau
        AssignedTo: nouveau at lists.freedesktop.org
        ReportedBy: pq at iki.fi
         QAContact: xorg-team at lists.x.org


Created an attachment (id=18068)
 --> (http://bugs.freedesktop.org/attachment.cgi?id=18068)
X log

I'm not sure when, but I recently found that X is generating a lot of bad
modes. This is xrandr output:

Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 1400 x 1400
VGA-0 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm
x 270mm
   1280x1024      60.0*+   75.0     60.0* 
   1400x1050      60.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       85.0     75.0     70.1     60.0  
   832x624        74.6  
   800x600       130.0    120.0     85.1     85.1     72.2     75.0     60.3   
 56.2  
   700x525       149.5    120.0  
   640x512       150.0    120.0  
   640x480       120.0     85.0     75.0     72.8     75.0     66.7     59.9  
   720x400        85.0     70.1  
   640x400        85.1  
   576x432       150.0  
   640x350        85.1  
   512x384       170.0    150.1    140.1    120.0  
   416x312       149.3  
   400x300       170.5    144.4    150.2    120.6    112.7  
   320x240       170.4    145.6    150.0    120.1  
   360x200       170.1  
   320x200       170.5  
   320x175       170.5  

This is a flat panel, and I'm quite sure it cannot accept modes above 85Hz,
maybe even lower. Furthermore, according to the log, there are lots of
doublescan modes. When anything switches to 800x600 mode, X picks a doublescan
mode, which won't work. If I manually do 'xrandr -s 800x600 -r 60'
the mode is
good.

Additionally, the included X log contains a line like the following for every
mode switch:

(II) NOUVEAU(0): Modeline "(null)"x0.0  108.00  1280 1328 1440 1688 
1024 1025
1028 1066 +hsync +vsync (64.0 kHz)

which is clearly a NULL dereference, but the gnu vsnprintf is so cool it
doesn't crash.

I'm running xorg-server and nouveau from git as of 1.8.2008.


-- 
Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

http://bugs.freedesktop.org/show_bug.cgi?id=16952


Pekka Paalanen <pq at iki.fi> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|nouveau at lists.freedesktop.or|xorg-team at lists.x.org
                   |g                           |
          Component|Driver/nouveau              |Server/general




--- Comment #1 from Pekka Paalanen <pq at iki.fi>  2008-08-16 08:44:19 PST
---
After discussion with malc0 and stillunknown, I'm reassigning this to
xorg-server.

EDID reported monitor freq ranges: V min: 50 V max: 85 Hz, H min: 30 H max: 82
kHz, PixClock max 140 MHz. There are several doublescan modes that actually fit
into the freq ranges, especially 800x600 at 65D. Xrandr reports doublescan modes
by showing the refresh rate as double, which can be seen in the xrandr output
in the previous comment. As higher refresh rates are automatically favoured,
this means doublescan modes get priority. E.g. 800x600 at 65D is in randr1.2
speak
800x600 at 130, which is then preferred over all normal 800x600 modes. As the
monitor cannot deal with doublescan modes, I don't get a picture by default.


-- 
Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.