AMD Sensor Fusion Hub Laptop Driver Unlikely To Land For Linux 5.7

While we were hoping to see the AMD Sensor Fusion Hub driver introduced in Linux 5.7 for improving the AMD Ryzen Linux laptop experience, that now looks quite unlikely.

This driver has been sought after by AMD Linux laptop customers since 2018 for supporting the accelerometer, gyroscopic sensors, and other functionality on modern AMD laptops, similar to the Intel Sensor Hub. Patches for the AMD Sensor Fusion Hub (AMD-SFH) driver for Linux were posted in January and underwent a few rounds of review.

After going through a few rounds of review, we've been hoping to see it for Linux 5.7 especially with the new AMD Renoir laptops beginning to ship in the near future. Sadly, however, Linux 5.7 looks out of scope for landing AMD-SFH.

The Linux 5.6 release potentially happening later today and that in turn opening the two-week-long Linux 5.7 merge window, but the AMD-SFH driver has yet to be pulled into the IIO subsystem's "-next" branch. But more pressing is that new issues with the code have now been raised.

On Friday upstream long-time kernel developer Andy Shevchenko reviewed the driver and found a number of faults with the code. The Intel engineer summed it up as "TL,DR; it requires a bit of work."

From missing header includes to seemingly bizarre to "completely useless" code that questions how much it was tested, the driver looks unlikely to see mainlined in its current form. The code review comments can be found via this mailing list post.

Given the changes/clean-ups needed, it looks almost certainly out of scope nope for seeing it potentially in the imminent Linux 5.7 merge window. That would punt it off to Linux 5.8 at least -- its merge window should be in June and see a stable release around August. At least if AMD-SFH gets into Linux 5.8, that should be the kernel used by the likes of Ubuntu 20.10 this summer.

For those wondering about the current state of AMD Ryzen laptop support on Linux, I do intend to buy an AMD Ryzen 4000 series laptop for Linux testing soon as I find an interesting model available at a decent price point. These laptops should start coming in the weeks ahead and given the successes I've had with AMD Zen 2 on desktops and servers, actually looking quite forward to seeing how well the Ryzen 4000 series will perform, albeit disappointed in cases like this of the much belated AMD-SFH support on the Linux side. If you too are interested in Ryzen 4000 Linux laptop testing, consider showing your support by joining Phoronix Premium or making a PayPal tip.