RHEL5.5 multiple displays on laptop

[violentwind]

Hello All,
This is my first time here.

I've been struggling trying to get a Lenovo T410 to display video on both it's internal LCD and an external display at the same time, and I need to get it working by Monday or I'm toast.

I know this will work with other distros, but we are contractually bound to use RHEL5.

If we use the laptop on it's own there is no problem, however once we set it in the docking station, the external display shows no video, unless it is rebooted. Then it will only display video on the external and not the laptops own display.

Our engineers are constantly going to meetings and need to be able to undock the laptop and have the display appear without having to reboot. Then conversely, return to their desks and have the video on the external display without rebooting.

I suspect that the problem is that RHEL5 is only up to release X11R7.1 of X.Org, which is still using version 1.1 of RandR and from what I can surmise, 1.1 of RandR does not recognize multiple video outputs.

I was hoping that someone more knowledgeable than I can confirm this and if I'm right do I need to manually build the latest release of X.Org to get this to work?

Thank you for your help,
Allen Rongone

The kernel we are at is: 2.6.18-194.11.3.el5
The T410 has the integrated Intel GMA HD graphics adapter

[Rubberman]

Open the KMenu Administration->Display tool. You should see the Display Settings form with 3 tabs: Settings, Hardware, and Dual head. The Settings tab is for the primary display (the LCD probably, but perhaps the external display if you are booting with it in the docking station). The Dual head tab is where you configure the other display. Enable the "Use dual head" checkbox and configure it. The "Desktop layout" combo-box will allow you to set it up for a single virtual display spanning both desktops, or separate desktops on each display.

[violentwind]

Open the KMenu Administration->Display tool. You should see the Display Settings form with 3 tabs: Settings, Hardware, and Dual head. The Settings tab is for the primary display (the LCD probably, but perhaps the external display if you are booting with it in the docking station). The Dual head tab is where you configure the other display. Enable the "Use dual head" checkbox and configure it. The "Desktop layout" combo-box will allow you to set it up for a single virtual display spanning both desktops, or separate desktops on each display.

Thanks for the reply Rubberman, however what you suggest does not work in the case of RHEL 5. Once I set it for dual-head, log out and login in again the Xserver fails with a fatal error > (EE) intel(1): Internal Error: maxCacheLines < 0 in i830_allocate_2d_mem

Anyway, I'm not really looking to get dual-head working, I just want to be able to mirror/clone the laptop's display with an external display.

Intel says that this should work "out-of-the-box" but it doesn't in RHEL5 with Xorg 7.1.1

[Rubberman]

That's another issue altogther, mirroring the displays. FWIW, it is possible. I do that with my Ubuntu laptop running 9.04 all the time for classes that I teach. You still need to use the display manager tool to do that. Since I only use twin-view (one desktop spanning both displays) on my CentOS/RHEL 5 workstation, I'll have to look into the means to do that for your situation.

[jocaster]

hello,violentwind
I am facing the same problem .
I was asked to setup a fujitsu lifebook p770/b to display video on both it's internal LCD and an external projector. The OS is RHEL 5.6
and the laptop use a Intel HD Graphics.
The laptop seems can't identify the Intel HD Graphics.I have tried to set the video driver to use intel but it's doesn't work.when I set it to vesa .the internal LCD worked.
I would like to know whether the X11R7.1(or the RHEL 5.6) can support the Intel HD Graphics.
and can I make the laptop's LCD and the projector display the same thing
in the same time with a vesa driver ?
hope for some advice.
thank you.

[Rubberman]

Most Intel graphics chip sets are supported out-of-the-box with Linux, but I think that the latest may not be. I read an article recently about progress of work being done on that. If this is a brand new system and the graphics chip set is the latest one from Intel (not sure the #), then you may need to use the generic vesa driver for now. However, that is the pits for full-motion video in my experience.