V3D Driver Fixes Glaring Performance Bug, VC4 Working Towards Proper GPU Reset

Eric Anholt of Broadcom's graphics driver team has provided another status update about their open-source Linux driver work in recent weeks on the VC4 driver stack mostly known for being the open-source 3D driver for the Raspberry Pi as well as the V3D driver for next-gen Broadcom VideoCore hardware.

Within the VC4 driver space, Anholt started writing a driver for the power management block that should be able to work more reliably and better for GPU reset handling than the current code they are using between the raspberrypi-power driver and the Raspberry Pi firmware.

On the V3D driver front for the next-gen VideoCore hardware, most notably is a fix for a 3ms wait that was happening on the CPU with every new job submission for the GPU. That's a significant wait for every job submission and with the kernel fix in place, throughput has improved by four and ten times. "Now I know why my fancy new hardware felt so slow!," Eric noted without revealing the details of this new hardware.

He's also been working on the kernel support for the Texture Formatting Unit (TFU), resurrecting work on compute shader work as a requirement for OpenGL ES 3.1, and other driver changes.

More details on the VC4/V3D driver progress via Eric's blog.