Bootlin contributions to Linux 5.13

After finally publishing about our Linux 5.12 contributions and even though Linux 5.14 was just released yesterday, it’s hopefully still time to talk about our contributions to Linux 5.13. Check out the LWN articles about the merge window to get the bigger picture about this release: part 1 and part 2.

In terms of Bootlin contributions, this was a much more quiet release than Linux 5.12, with just 28 contributions. The main highlights are:

  • The usual round of RTC subsystem updates from its maintainer Alexandre Belloni
  • A large amount of improvements in the MTD subsystem by its co-maintainer Miquèl Raynal, continuing his effort to improve the ECC handling in the MTD subsystem. See Miquèl’s talk at ELCE 2020 for more details on this effort: slides and video.
  • A small fix for an annoying regression in the musb USB gadget controller driver.

Even though we contributed just 28 commits to this release, as maintainers, some of us also reviewed and merged code from other contributors: Miquèl Raynal as the MTD co-maintainer merged 63 patches, Alexandre Belloni merged 22 patches, and Grégory Clement 6 patches.

Here are the details of our contributions to Linux 5.13:

Bootlin contributions to Linux 5.12

Yes, Linux 5.13 was released yesterday, but we never published the blog post detailing our contributions to Linux 5.12, so let’s do this now! First of all the usual links to the excellent articles on the 5.12 merge window: part 1 and part 2. also published an article with Linux 5.12 development statistics, and two Bootlin engineers made their way to the statistics: Alexandre Belloni in the list of top contributors by number of changesets, with 69 commits, and Paul Kocialkowski in the list of top contributors by number of changed lines, with over 6000 lines changed.

Here are the highlights of our contributions:

  • Addition of a new driver for the Silvaco I3C master controller. This was contributed by Miquèl Raynal, who became the maintainer for this driver. Bootlin has pioneered support for I3C in Linux, by introducing the complete drivers/i3c subsystem a few years ago, together with the first controller driver, for a Cadence IP, see our blog post from 2018.
  • Addition of two new camera sensor drivers, one for the Omnivision OV5648 and another for the Omnivision OV8865. These were contributed by Paul Kocialkowski.
  • Implementation of mqprio support in the Marvell Ethernet controller driver mvneta, see this commit. As explained in the tc-mqprio man page, the MQPRIO qdisc is a simple queuing discipline that allows mapping traffic flows to hardware queue ranges using priorities and a configurable priority to traffic class mapping. This was contributed by Maxime Chevallier
  • Improvements in the IIO driver for the ms58xx family of sensors, contributed by Alexandre Belloni.
  • The final removal of the atmel_tclib code, which has been replaced by proper drivers for the TCB timers on Atmel/Microchip ARM platforms over the past few releases, also by Alexandre Belloni.
  • As usual, a large amount of fixes and improvements in the RTC subsystem, by its maintainer Alexandre Belloni.

Here is the detailed list of our contributions to this release:

Linux 4.14 released, Bootlin contributions

Penguin from Mylène Josserand
Drawing from Mylène Josserand,
based on a picture from Samuel Blanc under CC-BY-SA
Linux 4.14, which is going to become the next Long Term Supported version, has been released a week ago by Linus Torvalds. As usual, did an interesting coverage of this release cycle merge window, highlighting the most important changes: The first half of the 4.14 merge window and The rest of the 4.14 merge window.

According to Linux Kernel Patch statistics, Bootlin contributed 111 patches to this release, making it the 24th contributing company by number of commits: a somewhat lower than usual contribution level from our side. At least, Bootlin cannot be blamed for trying to push more code into 4.14 because of its Long Term Support nature! 🙂

The main highlights of our contributions are:

  • On the RTC subsystem, Alexandre Belloni made as usual a number of fixes and improvements to various drivers, especially the ds1307 driver.
  • On the NAND subsystem, Boris Brezillon did a number of small improvements in various areas.
  • On the support for Marvell platforms
    • Antoine Ténart improved the ppv2 network driver used by the Marvell Armada 7K/8K SoCs: support for 10G speed and TSO support are the main highlights. In order to support 10G speed, Antoine added a driver in drivers/phy/ to configure the common PHYs in the Armada 7K/8K SoCs.
    • Thomas Petazzoni also improved the ppv2 network driver by adding support for TX interrupts and per-CPU RX interrupts.
    • Grégory Clement contributed some patches to enable NAND support on Armada 7K/8K, as well as a number of fixes in different areas (GPIO fix, clock handling fixes, etc.)
    • Miquèl Raynal contributed a fix for the Armada 3700 SPI controller driver.
  • On the support for Allwinner platforms
    • Maxime Ripard contributed the support for a new board, the BananaPI M2-Magic. Maxime also contributed a few fixes to the Allwinner DRM driver, and a few other misc fixes (clock, MMC, RTC, etc.).
    • Quentin Schulz contributed the support for the power button functionality of the AXP221 (PMIC used in several Allwinner platforms)
  • On the support for Atmel platforms, Quentin Schulz improved the clock drivers for this platform to properly support the Audio PLL, which allowed to fix the Atmel audio drivers. He also fixed suspend/resume support in the Atmel MMC driver to support the deep sleep mode of the SAMA5D2 processor.

In addition to making direct contributions, Bootlin is also involved in the Linux kernel development by having a number of its engineers act as Linux kernel maintainers. As part of this effort, Bootlin engineers have reviewed, merged and sent pull requests for a large number of contributions from other developers:

  • Boris Brezillon, as the NAND subsystem maintainer and MTD subsystem co-maintainer, merged 68 patches from other developers.
  • Alexandre Belloni, as the RTC subsystem maintainer and Atmel ARM platform co-maintainer, merged 32 patches from other developers.
  • Grégory Clement, as the Marvell ARM platform co-maintainer, merged 29 patches from other developers.
  • Maxime Ripard, as the Allwinner ARM platform co-maintainer, merged 18 patches from other developers.

This flow of patches from kernel maintainers to other kernel maintainers is also nicely described for the 4.14 release by the Patch flow into the mainline for 4.14 article.

The detailed list of our contributions: