Dell XPS 13-L321X Ultrabook

Laptop Specifications
Hardware specs may vary. These are the specs for the model XPS 13 Ultrabook:
 * Intel Core i5-2467M 1.6GHz to 2.3GHz or i7-2637M 1.7GHz to 2.9GHz, 3MB cache
 * 4-8GB Dual Channel DDR3 1333MHz
 * Intel HD Graphics 3000-4000 (on-CPU)
 * High Definition Audio with Waves MaxxAudio 4
 * 13.3in TFT LCD Widescreen screen (1366x768 or 1920x1080)
 * Samsung PM830 SATA 3 128GB or 256GB mSATA SSD Hard Disk
 * 1x USB 2.0 ports and 1x USB 3.0 ports
 * mini-DisplayPort output
 * Intel Centrino Advanced-N 6230 802.11 a/g/n with Intel Smart Connect Technology + Bluetooth 3.0

Printout of lspci:

Printout of lsusb (builtin devices, no external devices connected):

Printout of lsmod (builtin devices, no external devices connected):

Information from :

USB 2.0 Support

 * Compile the ehci-hcd driver as module.

USB 3.0 Support

 * Compile the xhci-hcd driver as module.

N.B. A kernel version 3.3 at least is required for the USB 3 support.

Drives and Storage

 * Hard Drive controller works using ahci driver in the kernel.

Graphics Chip
There is an issue with screen brightness which cannot be adjustable. There are two ways to work around this problem.

The permanent way to fix this issue is to apply this patch to the kernel sources. The patch is an attachment to kernel bug #47941. To apply the patch execute the following commands (tested in kernel 3.9.2).

The temporary way to work around the brightness issue is to run the following command. This is only a temporary solution because the command needs to be run on every boot, on every resume from suspend, and every time the screen is blanked by DPMS. This last issue is kernel bug #53491.

Use a script to run it at start up.

As well as after hibernate and suspend.

Both scripts need to be executable.

WLAN Card
You'll also need the firmware. Emerge either of the following packages.

or

Trackpad
The support for the Cypress trackpad was added in Kernel 3.9.0 thanks to the Sputnik project.

Webcam
The webcam will work using the v4l2 driver (tested) and sunplus driver (untested).

Test it out with mplayer:

Kernel
It is connected to the internal USB 2.0 port, so make sure to enable USB 2.0 support. You need PC-Card support. Also you need to activate the following kernel options:

Service
You can now start bluetooth:

To start bluetooth at boot time, add it your default runlevel:

Noisy fan
On the core i7 model, the fan is running too often and too early. A BIOS upgrade resolved the issue. http://www.dell.com/support/drivers/us/en/19/DriverDetails/DriverFileFormats?DriverId=C0VG5&FileId=2902722114&productCode=xps-13-l321x&urlProductCode=False

Wireless
When you're too close to a 802.11n router, the wireless hangs. This is a known issue but the bugzilla was disabled due to security issues.

You can workaround this firmware issue by disabling 11n on your iwlwifi module. First try a temporary workaround:

And if it works you can make it permanent: