Are you plugging the monitor into a laptop? I've had the same type of problem where my external monitor's display size was only a portion of the entire area, the area being used was the size of the LCD of the laptop. My solution was to add a line to grub in order to disable the laptop's display.
"video=LVDS-1:d" If this is relevant to you, you can find the name of the display to disable in /sys/class/drm On Wed, May 27, 2015 at 10:19:40AM +0100, Richard Melville wrote: > I've just configured my latest kernel (4.0.3) to utilise KMS (thanks Ken) > rather than the legacy vesafb, but of course this has created other > problems. > > The upside is that the font size on the console looks good on my monitor > (1440x900) and the backlight now switches itself off when required -- it > must have been broken on vesafb. > > The downside is that the EDID information fed to the kernel appears to give > the wrong screen size. Only about 60% of the width and height are used. > > Maybe there's something I've missed in the kernel config. I've now turned > off all legacy frame buffer settings that I can find, but it's made no > difference. > > My feeling is that the monitor EDID info is corrupt; it's a cheap and > fairly old model of unknown origin. If this is the case then I need to > build an EDID file and place it in /lib/firmware. But first I have to > discover exactly what the setting are for my monitor. > > My questions are: has anybody successfully built a custom EDID file, and > what is the best way to query the monitor for the settings? Normally I > would use xrandr, but I don't have xorg (with its libraries) installed, and > I don't need it. Can xrandr be installed standalone? I've found a couple > of other tools on the web (read-edid and edid-rw) but I'm unfamiliar with > them. > > Any help much appreciated, otherwise I'll plough on alone :-( > > Richard > -- > http://lists.linuxfromscratch.org/listinfo/blfs-support > FAQ: http://www.linuxfromscratch.org/blfs/faq.html > Unsubscribe: See the above information page -- http://lists.linuxfromscratch.org/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
