Samsung OSG Contributions to Linux Kernel 4.6

Linux 4.6 was released last week, and in this release, 4 engineers from the Samsung Open Source Group (OSG) contributed 200 patches that modified 7,556 lines of code in different Kernel subsystems. The following list is all 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 97 48.5%
Javier Martinez Canillas 57 28.5%
Shuah Khan 36 18.0%
Luis de Bethencourt 10 5.0%
OSG developers by changed lines
Mauro Carvalho Chehab 4533 60.0%
Shuah Khan 1580 20.9%
Javier Martinez Canillas 1425 18.9%
Luis de Bethencourt 18 0.2%

OSG Contributions to This Release

In this release, Mauro continued his work on the Media Controller Framework (MC) to better support DVB devices; he was responsible for a lot of improvements in the MC framework to support entities and pads that are needed for analog and digital TV drivers. Additionally, he wrote a generic function to create the media graph on these drivers to avoid duplicating the code for each device. Finally, he carried out his usual fixes and cleanups all over the media tree as a part of his maintainership duties.

On the media front, Javier worked on improvements for the tvp5150 video decoder driver including the addition of device tree and input connectors support. He also produced some fixes and cleanups for this driver as well as some other media drivers. For ARM/Exynos, he extended the max77686 Real Time Clock (RTC) driver to support other RTC chips allowing to remove the max77802 driver that had a lot of code duplication. Finally, he also did a lot of cleanups and fixes for drivers in other susbystems.

Shuah also worked mostly on media for this release by adding ALSA support to the MC. This is particularly complex since the media device has to be shared by both ALSA and V4L2 or DVB drivers, so there media lifetime management implications across subsystems. She also worked on extending the au8522 and au0828 to make use of the ALSA MC support and did fixed issues on the MC core. Finally, she added kselftest to test the MC API.

Luis did various cleanups and fixes on different subsystems, including thermal, xfs, DRM, net, ipv6 and mac80211.

The Impact of the OSG

According to LWN’s report for v4.6 contributions, Samsung contributed a total of 390 patches that changed 12,107 lines of code. This means that 51% of Samsung total patches and 62% of modified lines came from the OSG. That’s again a striking number taking into account that only 4 OSG engineers contributed to this release. Mauro made it into the top 20 contributors for 4.6 by changesets and changed lines, he alone accounted for 25% of all Samsung contributions in terms of changesets and 37.5% of changed lines.

Samsung OSG Contributions to Linux Kernel 4.6 - kernel-4-6-stats

The merge window for 4.7 is already open and as usual a lot of patches from the OSG members are already queued by maintainers for inclusion in different subsystems.

Author: Javier Martinez

Javier Martinez Canillas was a Senior Linux Kernel Developer for the Samsung Open Source Group with a focus working on ARM and Exynos SoC support.