Linux 6.5 Brings Improvements To Firewire Support

While it's likely been years since most of you touched any Firewire devices, for those still having any old DV cameras around or professional audio hardware with an IEEE-1394 interface, Linux 6.5 is bringing improvements to its Firewire subsystem that until recently has been rather dormant for years.

As I wrote about back in April, there's a new maintainer for the Linux kernel's IEEE-1394 (Firewire) code. While Firewire has been obsoleted by more recent USB and Thunderbolt technology, developer Takashi Sakamoto hopes to continue working on the Linux kernel code around it until 2029 while beginning in 2026 he will aim to help users migrate to newer standards. There still are apparently some still using it for audio devices and other niche areas or for supporting vintage hardware.

The days of old I/O ports including Firewire from one of my 2004 Linux motherboard reviews.

Among the work that Takashi still hopes to work out for Linux's Firewire code are implementations for other types of protocols atop it such as IPv4/IPv6 over the IEEE-1394 bus, SCSI transport, and more.

The good old days of Abit motherboards...

For the Linux 6.5 kernel, there is now asynchronous timestamps exposed to user-space. The IEEE-1394 OCHI specification defines a means of reading hardware timestamps from asynchronous communications. Only now with Linux 6.5+ is the kernel exposing those async hardware timestamps to the user-space so applications can make use of them if they so wish. There is an updated libhinawa library for reading those timestamps in user-space.

New Firewire code for Linux 6.5 also modernizes the IEEE-1394 PCM device driver to use the kernel's managed resource "devres" framework.

More details on the Firewire updates for Linux 6.5 via this Git pull.