A deluge of Linux driver patches have arrived to support a previously unheard of AMD branded GPU. Linux-centric site Phoronix reports that 207 patches for the 'AMD Radeon Sienna Cichlid' GPU are quite certainly for a Navi-based GPU. Further analysis helps it come to the conclusion that Sienna Cichlid is a codename used to disguise an RDNA2 'Big Navi' GPU.
The numerous AMD Sienna Cichlid GPU patches definitely provide hints of a next generation GPU. It has signs of being Navi based with "new VCN 3.0 capabilities for video encoding and DCN3 on the display front." Furthermore, it includes a number of alterations compared to existing Navi supporting code.
Phoronix notes that its initial data mining of the 207 patches show that they mainly leverage the existing Navi code paths. Several changes represent "the usual churn surrounding firmware, clock-gating / power management differences," when new hardware lines are added, it is observed. The major changes spotted thus far are in the aforementioned VCN 3.0 media engine and DCN3 display engine. Phoronix says it will continue to poke through the code for anything enlightening.
Previous leaks about timing with regard to RDNA2 graphics launches have tended to point towards September. Nvidia Ampere GPUs for consumers and Cyperpunk 2077 are expected to be released at about the same time. Neatly, the new Radeon patches are expected to be mainlined into Linux 5.9 in August before arriving in a stable release around October time.