Collabora’s Contributions to Linux 5.5 Improve the Panfrost Driver, More


Collabora continues to add numerous hardware improvements in the Linux kernel with their endless contributions, and today they’ve shared a list of contributions done as part of the latest Linux 5.5 kernel series.

In an attempt to improve the upstream support of devices powered by the i.MX 6 family of processors, Collabora’s developers improved the brcmfmac open source Broadcom Wi-Fi driver by fixing suspend support for devices that try to save battery life by cutting the power during sleep.

They also improved the Panfrost open source driver for modern ARM Mali GPUs, the Hantro VPU codec driver, the Chrome Embedded Controller, as well as the virtual media controller driver (vimc), and paved the way for bus format negotiation between DRM pipeline components.

“Right now this bus format selection is either static or implemented as an ad-hoc solution by a few DRM display controller drivers. His [Boris Brezillon] work aims at providing the basic building blocks to ease such a negotiation. This effort is not yet finished and will continue in the next release,” said Sebastian Reichel.

Also worth mentioning is the fact that Collabora’s developers added gamma LUT support for Rockchip RK3288 SoCs, which can be used by compositors to implement Night Mode for displays.

I recommend checking out the full list of contributions Collabora made to Linux kernel 5.5, broken by commits, Reviewed-by, Acked-by, Signed-off-by, Tested-by, and Suggested-by.

Linux kernel 5.5 introduced numerous goodies, among which we can mention full support for Raspberry Pi 4 SBCs, a new Airtime Queue Limits (AQL) feature that leads to better Wi-Fi connectivity, RAID1 with 3- and 4- copies in the Btrfs file system, as well as support for alternative names of network interfaces.

Also new in Linux kernel 5.5 there’s a new unit testing framework for the Linux kernel called KUnit, the ability to use CIFS as root file system, SMB multichannel support, various improvements to the Berkeley Packet Filter (BPF), and cross device offloaded copy for NFS clients.

Linux kernel 5.5 is available for download from, but it’s currently marked as “mainline,” which means that it’s not yet recommended for mass deployments. We recommend waiting for the Linux 5.5.1 kernel to be released before attempting to upgrade your machines to the Linux 5.5 series.

Last updated 4 years ago

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