[mythtv-users] Mythbuntu 96dpi driving me mad

[HP-mini]

On Sun, 2013-10-06 at 10:06 +0100, Al Bates wrote:
> thanks - I should have included my xorg.conf. !edid is already present
> 
> # nvidia-settings: X configuration file generated by nvidia-settings
> # nvidia-settings:  version 304.37  (buildd at allspice)  Sun Sep  9 05:59:26 UTC 2012
> 
> Section "ServerLayout"
>     Identifier     "Layout0"
>     Screen      0  "Screen0" 0 0
>     InputDevice    "Keyboard0" "CoreKeyboard"
>     InputDevice    "Mouse0" "CorePointer"
>     Option         "Xinerama" "0"
> EndSection
> 
> Section "InputDevice"
>     # generated from default
>     Identifier     "Mouse0"
>     Driver         "mouse"
>     Option         "Protocol" "auto"
>     Option         "Device" "/dev/psaux"
>     Option         "Emulate3Buttons" "no"
>     Option         "ZAxisMapping" "4 5"
> EndSection
> 
> Section "InputDevice"
>     # generated from default
>     Identifier     "Keyboard0"
>     Driver         "kbd"
> EndSection
> 
> Section "Monitor"
>     # HorizSync source: builtin, VertRefresh source: builtin
>     Identifier     "Monitor0"
>     VendorName     "Unknown"
>     ModelName      "TV-0"
>     HorizSync       28.0 - 55.0
>     VertRefresh    50
>     DisplaySize 740 420
>     Option "UseEdidDpi" "false"
> EndSection
> 
> Section "Device"
>     Identifier     "Device0"
>     Driver         "nvidia"
>     VendorName     "NVIDIA Corporation"
>     BoardName      "GeForce 8400 GS"
> EndSection
> 
> Section "Screen"
>     Identifier     "Screen0"
>     Device         "Device0"
>     Monitor        "Monitor0"
>     DefaultDepth    24
>     Option         "Stereo" "0"
>     Option         "metamodes" "TV-0: 1024x768 { ViewPortIn=1024x768, ViewPortOut=652x412+48+33 }"
> SubSection     "Display"
>         Depth       24
>         Modes      "1024x768"
>     EndSubSection
> EndSection
> 
> and reported in log:
> 
> [    25.463] (**) NVIDIA(0): Option "UseEdidDpi" "false"
> [    26.270] (**) NVIDIA(0): DPI set to (35, 48); computed from "DisplaySize" Monitor
> 
> and does not stop 96x96 being applied at startup.
> 
> i added the xrandr command to /etc/rc.local as a cludge but that does not work - it must be being overridden later in the startup
> 
> any other thoughts?
> 
> > Possibly the monitors EDID..
> > DPI is calculated from EDID if resolution is forced (& vice versa).
> > 
> > When you use the "DisplaySize" & the monitor has EDID, the reported DPI
> > is still used.
> > 
> > Need to add the following.
> > Option "UseEDIDDpi" "FALSE"
> > 
> > This could get messy if you have multiple displays & are not using
> > separate X screens.
> > 
> > Could use this to re-enable reported DPI (EDID) for specific monitor
> > Option "UseEdidDpi" "DFP-1"
> > 
> > On 5 Oct 2013, at 14:40, Al Bates wrote:
> > 
> >> ignore that - changed it to another value and system still restarts with 96x96 dpi
> >> 
> >> On 5 Oct 2013, at 14:35, Al Bates wrote:
> >>>> is reporting NVIDIA(0): DPI set to (35, 48); computed from "DisplaySize" Monitor
> >>>> which is set in /etc/X11/xorg.conf
> >>>> but when i run
> >>>> xdpyinfo | grep resolution
> >>>> it returns
> >>>> resolution:    96x96 dots per inch
> >>>> aargh!
> >>>> i can force the resolution to change by running
> >>>> xrandr --fbmm 736x406 && xdpyinfo | grep resolution
> >>>> which results in:
> >>>> resolution:    35x48 dots per inch
> >>>> but what is forcing the 96dpi override in the first place?
> >>>> thanks for any help
> > 
> _______________________________________________

That's a lot of overscan correction...

The nVidia driver is only a X server graphics driver..it allows no
framebuffer pre-X modesetting. This is handled by some other modesetting
driver.
I believe grub/plymouth or greeter could set default dpi..

If the nVidia driver has successfully loaded then it should not matter
what value DPI was previously set.

What does xrandr -q report.
Not sure the Xorg tools work properly with nVidia driver running (esp. with twinview).
Maybe use xrandr to set resolution & display size & dpi..in one command.

Could add this to (/etc/X11/xorg.conf) increase verbosity..
Option "ModeDebug" "True"