Trying to use fbset

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Posts: 2
Joined: 15 Dec 2011, 04:01

Trying to use fbset

Post by David1 » 15 Dec 2011, 04:40

Can anyone help with the use of fbset?
I have been trying for hours to get a special resolution but to no avail.
I have tried 'fbset -g 720 576 720 576 32 -t 37641 88 24 13 1 64 3 -sync low -vsync low'
and fbset always returns an error the moment I add a clock rate after the -t
(ioctl FBIOPUT_VSCREENINFO: Invalid Argument.)

Typing 'fbset -i' gives:

Mode "1024x768"
geometry 1024 768 1280 80 32
timings 0 0 0 0 0 0 0
accel true
rgba 8/16,8/8,8/0,0/0

Frame Buffer device info:
Name: inteldrmfb
Address: 0xd0030000
Size: 4096000
Type: packed Pixels
XPanStep: 1
YPanStep: 1
YWrapStep: 0
LineLength: 5120
Accelerator: No

However if I do this:
'fbset -g 800 600 800 600 32' or 'fbset -g 1024 768 1024 768 32' then it sort of works.
I say "sort of works" since the monitor still shows the resolution at 1024 X 768
(which is what Sysresc defaults to just after booting) just that by changing the resolution with fbset,
the viewable area just become smaller but the monitor still reports 1024 X 768.
What am I missing?
The above relates to CLI (no X running).

The motherboard is an Intel D410PT.
Thank you.

Posts: 1129
Joined: 07 Apr 2010, 16:19

Re: Trying to use fbset

Post by gernot » 15 Dec 2011, 16:06

I think your video card don't like this parameters.
Try too boot with "vga=ask" in the append line, then select the favorable resolution.
Now read the settings with fbset.


Posts: 2
Joined: 15 Dec 2011, 04:01

Re: Trying to use fbset

Post by David1 » 15 Dec 2011, 16:22

Hello, I'm starting to suspect that it's a fb/kernel issue as with the
exact same motherboard and graphics card, I booted to DOS, made
a simple driver to directly change the VGA registers with the same
resolution and it worked perfectly so I know that the hardware is capable of it.

Back in sysresc, the moment I add any pixel clock parameter (other then zero)
after the -t in fbset, it gives me the error even if it's a known good resolution.


No matter what resolution I set the card to, it always returns 0 0 0 0 0 0 0 for the timings with fbset.

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