About a decade ago, Allwinner was providing an "SDK" to vendors to customize the Linux kernel for their devices. This "SDK" was a tarball of the compiled Linux kernel. In it, there were object files for drivers by third-parties for devices in the SoC that Allwinner sourced from other companies. Allwinner had the source code but obviously could not release it. They did not think better, and included those object files because it helps device integrators (mainly Android) to get the job done.
How do you deal with this issue with this blatant GPL violation? Obviously, you do not alienate the company. They fcked up but it's not the end of the world. They cannot release the source code of parts they do not own. You build a relationship and get them through to the right path.
But what happened in reality? A colossal fck-up. An attempt to "blackmail" the company to release the full source code and enforce the GPL. Listen to this, an attempt to enforce the GPL to a company "located in China". Not even on vendors that sell products in Europe or the US.
This alienated any attempts to get Allwinner's upper management to work with Linux. Allwinner made an effort and released some stuff (https://github.com/allwinner-zh) including the bootloader source and documentation (2015). The damage was done.
In 2016, Linus and other kernel developers posted their position on enforcing the GPL (https://lwn.net/Articles/698452/). Very pragmatic and should have been followed with Allwinner.