Dell Latitude C840

Background

This is the 2nd Dell Latitude laptop, after seeing that this model is so new I decided to write up something for everyone else to look over and have some guidance on. I previously had a Dell Latitude C800; a great laptop for speed; but the C840 blows that away by comparison. I have it working with dual-boot of *cough* Microsoft Windows XP Professional and Linux Slackware and have no problems. The Dell Latitude C800 that I previously had kept locking up for some unknown reason but I got not support from Dell on that issue. By the way, I can use VMware to boot either side of the OSs without any problems.

Hardware

Model: Dell Latitude C840
CPU Model: Intel P4-M 1.6ghz 512k cache
Memory: 512MB DDR
Monitor: LCD 15" XGA
Hard Drive: Hitachi DK23DA-40 40GB UDMA100 Hard Drive
Video Card: nVidia GeForce 4 440 Go (64MB DDR)
Sound Card: Cirrus Logic Crystal CS4205
Optical Device: Toshibai CDRW/DVD SDR2102 Combination 8x/8x/8x/24x Rev: 1D13
Modem: PCTEL 2304WT v.92 MDC Modem
Network Adapter: 3Com 3c920
Docking Station Network Adapter: 3Com 3c920
PCMCIA: Texas Instruments PCI4551 PC Card Cardbus Controller
USB: Intel USB Standard Hub
FireWire (IEEE 1394): Texas Instruments OHCI Compliant IEEE 1394 Controller

Software

Distribution: Slackware heavy modified with security patches from Solar Designer's OpenWall set and many of others

Video Drivers: You will need to download the drivers from nVidia. These drivers allow XFree 4.3.0 to support this laptop in a multihead configuration.

Optical Device: If you've never worked with burning CDs on a laptop you might want to check with a more detailed documentation than what I'll give below. But if you're familiar with kernel compiling, you might be able to get it working. I use cdrecord and mkisofs to generate the CDs. In order to do this, you must have SCSI compiled in. So lets begin, 1) config must have SCSI Emulation enabled, 2) turn off IDE CDROM support, and 3) compile the kernel with SCSI CDROM and SCSI generic support. Recompile the kernel and you then should be good to go. To check execute 'cdrecord -scanbus' and it should find your cdrom. If not, then obviously something went wrong.
Sound: Kernel Drivers for sound using 2.4.18 using "Intel

ICH (i8xx) audio support"

Network: Kernel Drivers for network using 3Com's "3c590/3c900 series (592/595/597) "Vortex/Boomerang" support"

Modem: The PCTel modem was probably the last area that I got working. Just never had a need for it. But once I finally hit the road and needed a linux dialup the linmodem drivers worked instantly. From what I've gathered anything over version 0.9.6 should do just fine. Compile and select the Intel chipset with the --with-hal=i81x.

Dell BIOS: The linux kernel supports the Dell Inspiron BIOS in 2.4.18. I have no clue what it buys you but it does appear to detect it under the configuration option "Dell laptop support". In 2.4.20 and maybe 2.4.19, they've redefined the selection to be "Dell Laptop Support". This adds additional functionality for the i2p code for CPU overheading and such. Please refer more to the kernel help option under this function.
USB Support: Compile the linux kernel with "Support for USB", the controller of "UHCI (Intel PIIX4, VIA, ...) support" and any USB devices you have.

FireWire (IEEE 1394): Compile the linux kernel with "IEEE 1394 (FireWire) support". Please note it is experimental. If you do not have a need for firewire you might want to just disable it. Also, this probably will not come up as visible unless you have "Prompt for development and/or incomplete drivers" enabled. Then select the device driver of "OHCI-1394 support" and you should be set to go.

PCMCIA: Compile PCMCIA Support into the kernel. You will also need the latest PCMCIA-CS Drivers.

Port Replicator C-Port/2: The docking is plug and play with the above hardware. The network card is a 3c980 as above. It will be detected automatically. Video is a function of the BIOS. If it detects the docking station, it will automatically display through that first. USB devices work in the same function as well. Sound is another story. Currently, sound doesn't work through the docking station. Dell's support technicians states that the Port Replicator is nothing more than a pass-thru connection device and that it should work.
Posted Configurations

XFree86 4.2.1 Configuration file: XF86Config
Kernel 2.4.20 Configuration: .config

Todo

Under Microsoft XP I've gotten this laptop to work natively in a multihead configuration. I plan on getting the same worked out for Linux in its X configuration.

The sound cannot work on a docking station through the docking station due to Dell's setup. The linux kernel wants to use the internal PC Speakers and that is it. We've contacted Dell Tech Support regarding this issue and there doesn't appear to be any way around it. Its possible if you specify a specific PCI interrupt to *maybe* get it working.

Multihead is working under the latest NVidia drivers. We'll post the configuration shortly.

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