This well-known problem is due to the built-in Realtek Card Reader’s Linux driver. This issue affects other laptops as well, and is currently (in Ubuntu 12.04) unsolved.
This temporary ‘fix’ will produce the the following result:
- The card reader will be disabled by default
- All the USB ports (left and right side) are going to work by default
- You will be able to enable the card reader manually
- If you enable the card reader after connecting your devices to the USB ports on the right side, you will be able to use both the card reader and your USB devices at the same time
Here are the steps:
- Run Terminal and execute the following command:
sudo gedit /etc/modprobe.d/blacklist.conf
- Add the following line to the end of the file:
- Save the file and close gedit.
- After restart, your card reader will be disabled but all the USB ports are going to fuction properly.
Use this command to temporarly enable the card reader:
sudo modprobe rts5139
And this one to disable it:
sudo rmmod rts5139
To permanently re-enable the card reader, simply remove/comment out the blacklist rts5139 entry in blacklist.conf.
Source: Daniel Walton (launchpad)