The touchpad of Dell XPS 13 (2015) in I2C mode never works with trusty 3.13 kernel.
However the touchpad of Dell XPS 13 (2015) in PS/2 mode does work with trusty 3.13 kernel by default.
I need to use osi_acpi="Windows 2013" to make it function in I2C mode with trusty 3.13 kernel.
The touchpad of Dell XPS 13 (2015) in I2C mode never works with trusty 3.13 kernel.
However the touchpad of Dell XPS 13 (2015) in PS/2 mode does work with trusty 3.13 kernel by default.
I need to use osi_acpi="Windows 2013" to make it function in I2C mode with trusty 3.13 kernel.