Ubuntu14.04 startup prompt set_sw_statefailed

When ubuntu14.04 is installed, a problem always occurs during system startup.

Kernel: [16.465893] [drm: rv770_dpm_set_power_state] * ERROR * rv770_set_sw_state failed

The video card is ATI4330. After google, there are similar problems on the Internet. After reading some questions, I decided to upgrade the kernel and try again.

The original kernel is 3.13, from the ubuntu kernel site to see the latest relatively stable version is v3.15-rc2-trusty, So download and upgrade a bit.

Three files need to be downloaded. My computer is amd64, So I downloaded

Linux-headers-3.15.0-031500rc2_3.15.0-031500rc2.201404201435_all.deblinux-headers-3.15.0-031500rc2-generic_3.15.0-031500rc2.201404201435_amd64.deblinux-image-3.15.0-031500rc2-generic_3.15.0-031500rc2.201404201435_amd64.deb

After the download, install

Sudo dpkg-I linux-*. deb

After restart, the error disappears.