SPI Seeing Some Nice Performance Optimizations With Linux 6.0

Performance tuning work to the Linux kernel's Serial Peripheral Interface (SPI) subsystem will pay off for embedded systems and other SPI-heavy platforms with Linux 6.0.

For systems making heavy use of the SPI bus, Linux 6.0 should be an exciting update. SPI subsystem maintainer Mark Brown wrote in yesterday's SPI updates for Linux 6.0:

The big update this time around is some excellent work from David Jander who went through the fast path and really eliminated overheads, meaning that we are seeing a huge reduction in the time spent between transfers for single threaded clients. Benchmarking has been coming out at about a halving of overhead which is clearly visible in system level usage that stresses SPI like some CAN and IIO applications, especially with small transfers. Thanks to David for taking the time to drill down into this and push the work upstream.

David Jander's work is with the Netherlands-based Protonic. Across a number of patches are various SPI overhead reductions / performance optimizations. He also provided further optimizations for SPI's fast path.

The SPI changes for Linux 6.0 also include support for Intel Meteor Lake, Intel Thunder Bay, MediaTek's MT8188 / MT8365 SoCs, Microchip FPGAs, Samsung Exynos Auto v9 and 4210 SoCs, and NVIDIA Tegra241 support.