Linux 4.15 released, Bootlin contributions

Penguin from Mylène Josserand
Drawing from Mylène Josserand,
based on a picture from Samuel Blanc under CC-BY-SA

After a month of February busier than usual, with the renaming of our company from Free Electrons to Bootlin, our participation to FOSDEM and the welcoming of Maxime Chevallier, the latest addition to our engineering team, our article on the latest release of the Linux kernel arrives a bit late, more than a month after Linux 4.15 has been released by Linus Torvalds.

As usual, LWN.net did an interesting coverage of this release cycle merge window, highlighting the most important changes: The first half of the 4.15 merge window and The rest of the 4.15 merge window. Due to the now well-known Spectre and Meltdown vulnerabilities and the resulting effort to try to mitigate them, 4.15 required a -rc9, which happened the last time back in 2011 with the 3.1, Torvalds said.

According to Linux Kernel Patch statistics, Bootlin (now Bootlin) contributed 150 patches to this release, making it the 16th contributing company by number of commits.

The main highlights of our contributions are:

  • In the RTC subsystem, Alexandre Belloni made a number of improvements to various drivers, mainly making them use the nvmem subsystem where appropriate, and use the recently introduced rtc_register_device() API.
  • In the MTD subsystem, both Boris Brezillon and Miquèl Raynal made a number of contributions, mainly fixes.
  • For Marvell platforms
    • Antoine Ténart contributed a few fixes to the inside-secure crypto accelerator driver, used on Marvell Armada 3700 and Armada 7K/8K
    • Antoine Ténart also contributed fixes and improvements to the mvpp2 network driver, used for the Ethernet controller on the Marvell Armada 7K/8K. His improvements include preparation work to support Receive Side Scaling (RSS).
    • Antoine Ténart enabled more networking ports and features in some Armada 7K/8K boards, especially SFP ports on Armada 7040 DB and Armada 7040 DB.
    • Boris Brezillon contributed a few fixes to the Marvell CESA crypto accelerator driver, used on the older Orion, Kirkwood, Armada 370/XP/38x processors. He migrated the driver to use the skcipher interface of the Linux kernel crypto framework.
    • Grégory Clement enabled NAND support on Armada 7K, and contributed a number of fixes around MMC support for some Marvell boards.
    • Thomas Petazzoni contributed a few minor Device Tree enhancements for Marvell platforms: fixing MPP muxing on an older Kirkwood platform, enabling more PCIe ports on Armada 8040 DB, etc.
    • Miquèl Raynal contributed support for more advanced statistics in the mvpp2 network driver.
    • Miquèl Raynal added support for the extended UART for the Marvell Armada 3720 processor, both in the UART driver and in the Device Tree.
  • For the RaspberryPi platform, Boris Brezillon contributed a few fixes to the vc4 display driver, and added support for the new DRM_IOCTL_VC4_GEM_MADVISE ioctl, which can be used to ask the userspace applications to purge inactive buffers when allocations start to fail in the kernel.
  • For Allwinner platforms
    • Mylène Josserand contributed a fix for the Allwinner A83 clock driver, fixing I2C bus clocks.
    • Quentin Schulz contributed a few fixes to the sun4i-gpadc-iio.c driver, which is used for the ADCs on several Allwinner processors.
    • Maxime Ripard made a number of fixes to the sun8i-codec driver, fixing clock issues, left/right channels inversion, etc.
    • Maxime Ripard made a number of improvements to the sun4i DRM display driver.
    • Maxime Ripard improved the support for the A83 processor (described the UART1 controller, the MMC1 controller, added support for display clocks) and added the Device Tree for a new A83 device.
    • Maxime Ripard also did a number of cleanups and misc improvements in a significant number of Device Tree files for Allwinner platforms.
  • Thomas Petazzoni made a few fixes to the sh_eth network driver, used on several Renesas SuperH platform, as part of a recent project Bootlin did on SuperH 4.

Bootlin engineers are not only contributors, but also maintainers of various subsystems in the Linux kernel, which means they are involved in the process of reviewing, discussing and merging patches contributed to those subsystems:

  • Maxime Ripard, as the Allwinner platform co-maintainer, merged 108 patches from other contributors
  • Boris Brezillon, as the MTD/NAND maintainer, merged 34 patches from other contributors
  • Alexandre Belloni, as the RTC maintainer and Atmel platform co-maintainer, merged 50 patches from other contributors
  • Grégory Clement, as the Marvell EBU co-maintainer, merged 24 patches from other contributors

Here is the commit by commit detail of our contributons to 4.15:

Author: Quentin Schulz

Quentin Schulz is an embedded Linux and kernel engineer at Bootlin. In particular, he works on continuous integration testing for the Linux kernel, contributing to the http://kernelci.org project.

7 thoughts on “Linux 4.15 released, Bootlin contributions”

      1. The link leads to “https://bootlin.com/blog/linux-4-15/company/staff/maxime-chevallier/” (notice the extra “blog/linux-4-15/” part).
        Possibly some relative path issue?

        P.s. FF 59.0.1 64-bit on Ubuntu 16.04

  1. Thank you all for you great work. Even thought I don’t directly use most of the hardware Bootlin works on, seeing that all this work is being put into making Linux better makes me a huge fan. Cheers!

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