Apple Magic Mouse with Dell Latitude E6520

Recently, I found some free time at office and my colleague's Apple magic mouse was lying on my table. It sure is a cool device. So, I thought why not connect it to linux and see how it works. So, I turned on the bluetooth daemon on my system with the following command.

systemctl start bluetooth

I use Bluedevil. So, I clicked on the tray icon and ran a scan for bluetooth devices in range. The pairing key required is 0000. Initially the mouse pointer movement was too fast and scroll was too slow. So, I changed the configuration using this blog.

It is cool, indeed. However, I found it difficult for regular use because I am not used to it and it is a touch mouse unlike other mice. When I am moving the mouse, I have to make sure my index finger is not touching the surface, else there is unwanted scrolling.

Webcam on Dell Latitude E6520 on Arch linux

On my Dell Latitude E6520, I have a webcam integrated into the front panel. I am not very used to video calls so I hardly use it. However, recently I wanted to talk to my brother using video call on Skype. So, I started digging in so that I can configure it. The first step was to see if it is already configured and works out of the box. I tried getting video to work during a Skype call; but it did not. So, I started looking for the actual model. I got the following output on lsusb.


Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 413c:8187 Dell Computer Corp. DW375 Bluetooth Module
Bus 001 Device 004: ID 05ca:181c Ricoh Co., Ltd
Bus 002 Device 003: ID 0a5c:5800 Broadcom Corp. BCM5880 Secure Applications Processor

I could not figure out which one is the webcam. So, I looked into the output of lspci as well; but nothing there either. So, I was having a hard time figuring out which device is my webcam. The other question running in my head was the rare possibility of my kernel not detecting my webcam. I checked out /var/log/dmesg.log to see if it was detected. I ran the following grep.

grep webcam /var/log/dmesg.log

I was disappointed to find nothing. After some time, I realized my mistake and tried the grep query in case insensitive mode.

grep -i webcam /var/log/dmesg.log

This time I found the device.

uvcvideo: Found UVC 1.00 device Laptop_Integrated_Webcam_FHD (05ca:181c)
input: Laptop_Integrated_Webcam_FHD as /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.5/1-1.5:1.0/input/input8

Looking at the output I tried loading the uvcvideo kernel module and tested the webcam with the following vlc self-recording command.

vlc v4l:// :v4l-vdev="/dev/video0"

It worked fine. So, I looked into the Arch wiki for more details. It mentioned that linux-uvc was now in kernel. Looking into a more exhaustive list of devices supported by uvcvideo, I found the following matched my device closely.

05ca:181a
05ca:181b

So, I guessed 05ca:181c should also be supported by uvcvideo but being a new model was not listed there. So, I have reported this to the dev team and added the module uvcvideo the list of modules in my rc.conf.

MODULES=(acpi-cpufreq cpufreq_ondemand cpufreq_powersave uvcvideo)

Interestingly it is a Ricoh device but the driver is not the Ricoh driver [mentioned in the wiki].

Reboot on Dell Latitude E6520 with Arch linux

On Dell Latitude E6520 and some other Latitude models, a number of distributions were having issues with reboot. Rebooting by any method, viz.

• restart command
• shutdown -r now command
• or restart from GUI

stopped all processes. The run level goes to 6 and everything works fine. Finally the system shows a message that it is rebooting now but the reboot does not happen. Ubuntu had this bug too but they fixed it and when my friend tried Ubuntu on the same hardware, reboot worked fine for him. I filed a bug in Arch and discussed it on #archlinux. The developers said it is an upstream issue and I was able to find an already reported bug upstream. Looking into the bugs and comments, I figured I should try setting the kernel parameter 'reboot' to 'pci'. So, I changed the kernel line in /boot/grub/menu.lst to include 'reboot' parameter as follows.

kernel /boot/vmlinuz26 root=/dev/sda2 resume=/dev/sda1 ro reboot=pci


After the above change, my system rebooted successfully.


N.B.: 1. Here, /dev/sda2 is my root partition and /dev/sda1 is my swap partition.
         2. Read more about rebooting a system.