Issues with Centos 7.1 and Dell XPS 8700

[snsina]

Hi,

Recently, I ran yum update on my Dell XPS 8700 using CentOS 7.0. After finishing updates I rebooted the machine and couldn't boot the OS,
Even installing the CentOS 7.1 on the same machine had some issues.
1. The screen is blurry and fonts are not readable. If I update it from 7.0 to 7.1 with YUM update I get the same error for generic video card driver. ( I don't have this issue with version 7.0)
2. The newly installed 7.1 does not recognize Wireless device.

I didn't spend more time on it but probably we can get more issues with this update.