Here's an interesting interview concerning the state of open-source Linux SoC graphics drivers.
A Phoronix reader, Emmanuel Deloget, has written in to share an interview he carried out on his personal blog of various ARM SoC GPU driver developers. The drivers covered include Lima (ARM Mali), GRATE (NVIDIA Tegra), Videocore (Broadcom), Freedreno (Qualcomm Adreno), and etna_viv (Vivante) hardware.
The interview covers the state of the drivers, motivation behind these drivers, project challenges, and much more. The interview can be read at emmanueldeloget.com