This year the Embedded Linux Conference Europe (ELCE) is back in Prague! Pengutronix, again, is on a field trip with 15 colleges to attend the conference. The ELCE is one of the big conferences where the Embedded Linux Community meets during the year. This time the ELCE is part of the Embedded Open Source Summit (EOSS): a new conference with only embedded topics and without cloud- or crypto-tracks.

In this blog post we showcase the talks our colleagues will present at the ELCE. (Links to recordings will be added once the recordings are available.)

Oleksij Rempel: Braiding Wires Into the Linux Network Stack - Recent Work on Embedded Networking

Links for this talk

Oleksij Rempel, Wednesday, June 28 • 16:05 - 16:45, Schedule and Slides, Recording

Over the last few months, Oleksij Remepel has spent some time extending the Linux kernel's network infrastructure for embedded use cases - this includes, industrial, medical and automotive devices. As usual, any driver development starts from the basics and goes to advanced topics. The driver developer starts with the default hardware settings and makes them work. For example, with a Gigabit Ethernet controller, the first use case is a 1000BaseT full duplex link. While this works for most applications, some embedded use cases have special requirements. This talk will look into topics like: Energy Efficient Ethernet (EEE), Single Pair Ethernet (SPE), diagnostics and many more.

Lucas Stach: Why Are GPUs (Not) Fast - A Trip Through the Driver Stack

Links for this talk

Lucas Stach, Thursday, June 29 • 14:10 - 14:50, Schedule and Slides, Recording

GPUs are often called accelerators and everybody tells us that they are supposed to make all things graphical go really fast. So why do they sometimes fall short of expectations and is there something we can do about it? This talk will first give a brief introduction to GPU hardware and how it differs from the traditional CPU. It will then work its way up through the different parts of the GPU driver stack until reaching the user visible APIs like EGL, OpenGL and Vulkan. The audience will gain a basic understanding on how the GPU hardware and drivers work and how to best utilize them both. Understanding the driver stack below the sometimes very abstract user APIs will help attendees of this talk to avoid performance pitfalls and utilize more of the acceleration potential when writing applications using the GPU. They will also gain a understanding how the graphics stack ties into the greater Linux ecosystem.

Johannes Zink: Do the Time Warp – the Rocky Horror PTP Show: Verification of Network Time Synchronization in the Real World

Links for this talk

Johannes Zink, Friday, June 30 • 14:00 - 14:40, Schedule and Slides, Recording

Many realtime network applications require tight time synchronizations between the different nodes in a network. The Precision Time Protocol PTP can provide clock synchronization down to the nanosecond range. In order to achieve such tight synchronization, hardware timestamping of PTP packets is used, for which the Linux kernel provides the kernel PTP hardwareclock infrastructure, while linuxptp implements the PTP protocol stack in userspace. Proper configuration of the components involved and the setup of the PTP daemons and hardware can be a difficult task, because even minor configuration issues have a huge impact on the overall performance. After a short introduction into PTP and synchronization of PTP hardware clocks, this talk introduces different methods for measuring clock synchronization and compares their advantages and disadvantages. Using examples from real world projects, this talk will show common pitfalls when starting to set up new PTP projects and how to avoid them. Last but not least, this talk will show misleading software debug outputs, time jumping back and forth, and many more fun effects you can encounter when setting up PTP in your network for the first time and how to debug these issues.