Oleksij: Energy Efficient Ethernet in the Linux Kernel: Taming the Wild West of Implementations

Energy Efficient Ethernet (EEE) promises a greener future for networking, but its implementation within the Linux kernel has been a bit of a wild west. Inconsistent interpretations of the IEEE 802.3 standard have led to a patchwork of EEE implementations, often riddled with errors or simply blacklisted due to complexity. This presentation takes you on a journey through the EEE landscape, shedding light on the common pitfalls and misconceptions that have plagued its adoption. The speaker, a seasoned wrangler of network drivers, will unveil the recently enhanced PHY framework, a powerful tool designed to tame the EEE wilderness and bring order to the chaos. Discover how this framework streamlines EEE initialization, minimizes errors, and paves the way for a more energy-efficient future. Learn from the mistakes of others as the speaker highlights common implementation blunders and provides expert guidance on how to avoid them. Whether you're a seasoned kernel hacker or a curious network enthusiast, this presentation promises to equip you with the knowledge and tools needed to conquer the EEE frontier and build a more sustainable network ecosystem.

Oleksij: Graceful Under Pressure: Prioritizing Shutdown to Protect Your Data in Embedded Systems

Power fluctuations are a common challenge in embedded systems, where components like SD cards, eMMCs, and raw NAND flash are widely used for storage. These storage components are vulnerable to data corruption or even permanent damage when power unexpectedly drops. While larger systems, such as servers, often employ solutions like uninterruptible power supplies (UPS) to mitigate this risk, the size and cost constraints of embedded devices often preclude such measures. Although some modern embedded systems can detect power issues early, a unified, upstream solution for gracefully shutting down critical components is still lacking.

In fact, software-based solutions for prioritized shutdown already exist in some Linux-based embedded systems. However, these solutions are not integrated into the mainline kernel. This fragmentation makes it difficult for the broader community to benefit from these advancements.

This talk aims to bridge this gap by advocating for the inclusion of prioritized shutdown mechanisms in the Linux kernel. We will discuss the unique challenges faced by embedded systems, where size and cost constraints often limit hardware-based protections like UPS systems. By leveraging existing software solutions and collaborating with the community, we can develop a standardized approach to power loss protection that benefits all embedded Linux users.

Join us as we explore the technical and community aspects of this issue, with the goal of making graceful shutdowns a standard feature in all Linux-based embedded systems. Let's work together to protect our data, even when the power flickers.

Marc and Oleksij: Linux-CAN Subsystem: BoF - State of the Union and Outlook

Marc (Linux kernel CAN subsystem maintainer) and Oleksij (Linux kernel J1939 maintainer) will give an overview of current best practices for the Linux CAN subsystem and J1939 stack.

They will address high latencies in the RX path, presenting a two-step approach to avoid buffer overflows and out-of-order reception using the RX-Offload helper.

Modern CAN controllers provide RX and TX-complete time stamps. In order to use them in user space, they need to be converted from the CAN controller's internal clock to the kernel representation in nanoseconds. Marc and Oleksij will give a short introduction to the cyclecounter/timecounter helpers that should be used by new drivers.

They will also discuss future goals like configurable CAN frame queuing (FIFO vs. priority) and using ethtool for CAN HW filter configuration.

Updates on the J1939 stack adoption, validation efforts, and user space ecosystem enhancements will also be covered.