December 15, 2016 - Javier Martinez Canillas

Samsung OSG Contributions to Linux Kernel 4.9

Linux 4.9 was released on December 11, making this release the biggest to date in number of changes. In this development cycle, the Samsung Open Source Group (OSG) contributed 394 patches that modified 15,856 lines of code. Although 4 engineers contributed to different Kernel subsystems, most of the changes comes again from Mauro Carvalho Chehab’s work to improve the Linux kernel documentation.

The following is a list of the OSG engineers that contributed to this release and the number of changesets and lines of code, as reported by Jonathan Corbet and Greg Kroah-Hartman’s gitdm tool.

OSG developers by changesets
Mauro Carvalho Chehab 238 60.4%
Javier Martinez Canillas 108 27.4%
Shuah Khan 24 6.1%
Luis de Bethencourt 24 6.1%
OSG developers by changed lines
Mauro Carvalho Chehab 14,747 93.0%
Javier Martinez Canillas 518 3.3%
Shuah Khan 314 2.0%
Luis de Bethencourt 277 1.7%

OSG Contributions to This Release

On this release, Mauro continued working on the media documentation, mostly fixing pending issues from the DocBook to the Sphinx doc conversion. He also handled the usual cleanups and fixes all over the media subsystem, specifically drivers that use stack-allocated memory for DMA since there are no guarantees that the stack would be in a DMA enabled area. Not to mention, this isn’t even possible when the new CONFIG_VMAP_STACK config is enabled.

Shuah also helped to improve the Linux documentation by moving compilable code out of the Documentation directory; this is necessary to get rid of the CONFIG_BUILD_DOCSRC config option. She also fixed a bunch of issues in the s5p-jpeg and s5p-mfc Exynos media platform drivers. Finally, she identified a situation where the Light Display Manager failed to start on v4.9 when using the xf86-video-armsoc DDX driver. Find more details on the issue and a patch to xf86-video-armsoc in a post she wrote.

Javier did a tree-wide cleanup on the ARM Device Trees as part of the preparation to remove the skeleton.dtsi file, and fixed module autoload in a lot of platform drivers whose support for it was broken. He also fixed a lot of issues on the s5p-jpeg, exynos4-is, and exynos-gsc Exynos media platform drivers.

Most of Luis’ contributions were fixes and improvements to the Be filesystem, as part of his new role as befs maintainer. In addition, he also fixed issues with the wilc1000 and wilc1000 staging drivers.

The Impact of the OSG

According to LWN’s report for v4.9 contributions, Samsung contributed a total of 535 patches that changed 25,438 lines of code. This means that 74% of Samsung total patches and 62% of modified lines came from the OSG.

On this release, Mauro and Javier were listed in the top 20 most active developers by changesets and Mauro was also listed in the 20 most active by changed lines:

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The merge window for 4.10 is currently open and OSG patches are already being merged for the next release. We’ll provide a more detailed update of this work after Linux 4.10 is released.

Javier Martinez Canillas

About Javier Martinez Canillas

Javier was a Senior Linux Kernel Developer for the Samsung Open Source Group. He has contributed to different kernel subsystems with a focus on ARM and Exynos SoC support. Besides hacking, he enjoys spending as much time as possible with his wife Tami and their twins, running, reading and writing technical articles like "Kbuild: the Linux Kernel Build System", published by the Linux Journal.

Image Credits: OSDC

Development / Linux Development Process / Kernel Release / Linux /

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