[solved] Framebuffer + TFT

deejay · Posted: Thu Feb 16, 2006 6:54 am Post subject: [solved] Framebuffer + TFT

Hello,

i've a problem with Framebuffer and my TFT. First everything looks fine, but after a few minutes,
the TFT turns off. The Resolution in the Kernel config is 1280x1024@75 an the paramteters in my
grub.conf are 1280x1024-32@75. But if i type in fbset, you can see that the Frequency is
85 Hz and not 75 Hz. The maximum usable Frequency for the TFT is 75 Hz. I think that's the reason
why the TFT turns off. X works fine, i only have this problem with the Framebuffer support.

Anyone an Idea how i can fix the Problem. I use vesafb-tng...

Greets
deejay
_________________

deejay · Posted: Sun Feb 19, 2006 8:25 pm Post subject:

no idea?
_________________

Suicidal · l33t Joined: 30 Jul 2003 Posts: 959 Location: /dev/null

try

deejay · Posted: Sun Feb 19, 2006 9:36 pm Post subject:

Hello,

I've already tried this parameters, but the problem still exist.

This is my grub kernel line:

deejay · Posted: Wed Feb 22, 2006 9:55 am Post subject:

other Ideas?
_________________

deejay · Posted: Fri Feb 24, 2006 8:23 am Post subject:

no other ideas??

Is there anyone, who has the same problem?
_________________

Wonkey_Donkey · Tux's lil' helper Joined: 14 Oct 2003 Posts: 93

Have you checked your power management settings ? Is it set to switch the screen off after so long ?

My laptop does this by default when first setup.

deejay · Posted: Sun Feb 26, 2006 1:52 pm Post subject:

I think it has nothing to do with the Power Management Settings because with the nvidiafb it works fine.
It seems, that vesafb-tng ignore the the Grub Config line where I define the Resolution for my TFT. I set
the Frequency to 75 Hz but when I use fbset, you can see, that the Frequency is 85 Hz, and not 75 and
that is the reason the TFT turns off after a minute or so, i think.
But i dont find a way to fix the Problem

_________________

linuxtuxhellsinki · l33t Joined: 15 Nov 2004 Posts: 700 Location: Hellsinki

Why are you using so high freq, cause what I've understanded is that TFT/LCDs are not using those anyway.
I've always used 60Mhz on my laptops and readed that it's the correct one for laptops(TFTs)

So try

deejay · Posted: Mon Feb 27, 2006 6:36 am Post subject:

I've already tried a lower freq, but it's the same Problem. The maximum usable Freq for the TFT is 75 Hz.
With X everything works fine, only the Framebuffer doesnt work correctly.
_________________

brianhearn · n00b Joined: 04 Nov 2003 Posts: 72

Think I'm experiencing the same problem with the TFT I just bought - Yusmart 198YP. Framebuffer works right up until I start X, then the monitor reports it being out of range on the console, yet X works perfectly. I've removed the framebuffer for the time being but would be interested in a solution if anyone has one.
_________________
http://www.gentoo-clan.org - http://brian.gentoo-clan.org

deejay · Posted: Wed Mar 22, 2006 7:24 am Post subject:

I've found a solution. In my Kernelconfig, i've changed the resolution to 1024x768@60 and then i've build an new
initrd file for 1024x768.
Then i've changed the grub line like this: 1024x768-24@60

Now everything works fine. I don't know why, but it works....

_________________