Raspbian DRM Updated, DSI Driver Not Yet Ready For Upstream Due To Firmware Blob Issue

Eric Anholt of Broadcom has written a blog post detailing his past week of work on the open-source VC4 driver stack that benefits the Raspberry Pi.

Last week Eric was updating the Raspbian DRM code with the latest upstream changes. One notable addition is that DSI displays should now light up by default in conjunction with the open-source driver. However, this DSI driver found on Raspbian isn't yet ready to be upstreamed in the Linux kernel.

Eric explained why this DSI panel driver isn't yet ready to be mainlined, "because the closed-source firmware is getting in the way of Linux by stealing our interrupts and then talking to the hardware behind our backs. To work around the firmware, I never talk to the DSI hardware, and we just replace the HVS display plane configuration on the DSI's output pipe. This means your display backlight is always on and the DSI link is always running, but better that than no display."

Eric has also been moving the VC4 driver documentation from FreeDesktop.org over to GitHub. More details via this blog post.