AMD is a pretty big name in the technology world. The semiconductor manufacturer, which rarely pursues legal action against others (at least publicly), has filed a patent infringement complaint with the U.S ITC against several other entities. It asserts that the offensive uses of those technologies negatively impacts AMD and its licensees.
The complaint alleges that MediaTek, LG, Vizio, and Sigma Designs infringe upon three graphics processing patents (two of those belonged to ATI Technologies and the other is one that AMD has filed itself). These patents cover things like unified shaders, parallel pipeline graphics systems, and so on. The truly confusing part about this complaint is that AMD is going after companies who license GPU technologies from ARM and Imagination; as Anandtech says, it's easier to go after infringing physical products than ideas.
In this case, AMD is targeting specific system-on-chips like the MediaTek Helio P10 and the Sigma SX7. LG uses the P10 in some of its handsets and Vizio has the latter in some of its UHD TVs, which is why both of these companies are listed in the complaint. It specifies that these are not the only offending products, only that they are examples.
AMD's complaint is thus far pretty vague — it does not specify which of ARM's GPUs infringes on its patents. A few years ago, AMD announced that it would be monetizing its patent portfolio and it has since made licensing deals with various companies in regards to graphics processing.
If the ITC grants AMD's request, then any infringing product manufactured by the defendants will be banned from import and sale in the United States. This would obviously affect LG and Vizio.
Be sure to check out the source link if you're interested in a bit deeper reading (especially if you're an IP law nerd like me).