Comparing Snapdragon 810 v2 and v2.1

Around a few weeks before the launch of the Xiaomi Mi Note Pro, I was digging through kernel source to understand Snapdragon 810 and some other Qualcomm SoCs. We had kept track of MSM8994v1 and MSM8994v2, which were relatively well understood in terms of what they represented. V1 was an engineering sample variant, which was discussed as early as September in 2014. This variant set both the A57 and A53 clusters to a ~1 GHz maximum. V2 was the first mass production revision, which was present in both the LG G Flex 2, and HTC One M9. However, shortly before the launch of the Mi Note Pro, we noted references to v2.1 in various kernel source trees. There wasn’t much of note other than a change to the chip ID and other identifying information at this point. It’s also important to note that phones that definitely didn’t have this variant of the SoC still had references to it in kernel source. The only way to truly verify whether a device has a certain revision of an SoC is to either see whether the file is included in the compilation process or to verify the revision by checking the device itself.