How do I force a particular KMS native resolution for a monitor that lacks EDID?
Alex Villacís Lasso
a_villacis at palosanto.com
Wed Dec 16 14:29:20 PST 2009
Maybe this is not the proper list for this question. If this is so,
please indicate the proper place for this question.
I have a Fedora 12 x86_64 system, with an intel video chipset. This
system uses a Princeton flat panel connected through a standard VGA
cable. This flat panel is odd since it does not report any EDID data to
the video chipset, and therefore cannot inform the system of its maximum
resolution. However, through trial and error, I found out that the
maximum native resolution is 1280x1024.
I know this is not a chipset or driver problem, because a different
(older) monitor plugged in the same system does report EDID information.
The issue is that KMS, in the absence of EDID information, wants to use
a default resolution of 1024x768 (was 800x600 until I upgraded the
distro kernel), which underutilizes the monitor. Unless I take action,
this suboptimal resolution persists through all the boot process and
into the graphical desktop and any virtual consoles. I have added a
xorg.conf file to specify the 1280x1024 mode, and it works - for the
graphical desktop only. I have also added video=1280x1024 as a kernel
parameter in my grub.conf file, and it also works - for the virtual
consoles only. However, I cannot find yet a way to make plymouth use
1280x1024 as the resolution for the graphical boot. What happens instead
is that the kernel switches into 1280x1024, then plymouth switches back
into 1024x768 for the duration of the graphical boot, and only changes
back into 1280x1024 when the graphical login takes over.
Is there a way to specify the KMS screen resolution for plymouth, or
else to make plymouth (and hopefully X) use the 1280x1024 setting that
was already set by way of kernel parameters? I have tried googling
around and there seems to be no information on how to do this, or
whether this is even possible.
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