VC4 DRM Driver Gets Patched For BCM2711 / Raspberry Pi 4 Support

While the Linux 5.5 kernel landed Broadcom BCM2711 SoC and Raspberry Pi 4 enablement, one of the loose ends has been getting the open-source "VC4" DRM driver wired up for the display hardware on this latest Raspberry Pi. Patches are now pending for VC4 DRM to provide that display support and could potentially see it mainlined for Linux 5.7.

Maxime Ripard sent out the big set of 89 patches today for supporting the display pipeline found on the Broadcom BCM2711, the SoC used by the Raspberry Pi 4 that launched last year.

So many patches to the VC4 Direct Rendering Manager driver are needed due to this Broadcom SoC now having a second HDMI controller and various other changes causing a lot of code churn as a result. With these patches that add around three thousand lines of new driver code and rework another thousand lines, it's enough to get the Raspberry Pi 4 / BCM2711 display support working via HDMI but not other outputs yet. Another limitation is dual HDMI outputs not yet being supported.

These initial patches can currently be found on dri-devel. If they are reviewed and deemed in good shape within the next two weeks or so, it's possible we could see the work land in DRM-Next for making the Linux 5.7 merge window in about one month's time.