Hi all,
I thought it was DMABUF, but the option is about DMA_FENCE actually. It is named CONFIG_MALI_DMA_FENCE in the kernel configuration and can lead to very good performance improvements when enabled. You might have to recompile your kernel if such support is not enabled though.
More recent user-space binary drivers might fail to initialize if the currently used kernel driver version is not equal or superior. So for example, Midgard r12p0 user-space drivers can be used with Midgard r16p0 kernel drivers, but cannot be used with r11p0 kernel drivers.
Concerning the driver denying lower polling timings, I don't know what could cause this exactly. The value might be hardcoded in 4.4 kernels provided by Rockchip. : github.com/.../mali_kbase_rk.h .
Meanwhile, I'll try to add Mali support to Firefly's 4.12 DTS files.