how to sync with mainline
nicolas.pitre at linaro.org
Thu Mar 17 01:03:49 UTC 2011
Sorry for not answering earlier. I was on vacation last week, and my
email backlog is incredibly large. I'm going through it with generous
usage of the delete key so it is possible that I might have missed
On Fri, 11 Mar 2011, Barry Song wrote:
> 2011/3/9 Lee Jones <lee.jones at linaro.org>:
> > On 09/03/11 02:44, Barry Song wrote:
> >> 2011/3/8 Amit Kucheria <amit.kucheria at linaro.org>:
> >>> On Tue, Mar 8, 2011 at 10:34 AM, Barry Song <21cnbao at gmail.com> wrote:
> >>>> Hi Lee,
> >>>> Great! Thanks a lot. It looks like the communication between linaro
> >>>> and mainline is that linaro can backport some bug fixes and features
> >>>> from mainline to linaro tree. Linaro doesn't help to review patches
> >>>> and send to mainline.
> >>> We prefer to see it this way:
> >>> Develop against mainline and get those features integrated there. Keep
> >>> linaro-dev in cc if these are features might be something Linaro would
> >>> care about.
> >>> The Linaro kernel (maintained by Nicolas Pitre and packaged by John
> >>> Rigby) is a sort of technology demonstration to show what we achieve
> >>> every 6 months. Some patches in it are backports, others are features
> >>> that are still under review in mainline. But I doubt if Nicolas will
> >>> take un-reviewed code directly into his tree.
> >>>> Then I have two more questions
> >>>> 1. is there a detailed list of backport and bug fix in linaro kernel
> >>>> tree since those are the difference between mainline and linaro tree?
> >>> 'git log' with the right incantations should be able to tell you that.
> >>> Look up Nicolas' email announcements for the high-level overview of
> >>> what he has integrated.
The general policy for the Linaro kernel tree is described here:
> >>>> 2. will linaro accept patches from non-member companies and help to
> >>>> maintain, I mean a SoC company which doesn't join linaro?
> >>> Linaro doesn't want to maintain dead code that isn't going upstream.
> >>> It won't even do it for member companies. At most it is the incubator
> >>> where the code lives and gets wider testing _while_ it is being
> >>> reworked for mainline.
> >> If patches are going mainline, but they are not from members TI,
> >> Freescale, ST-E etc, can they be merged into linaro kernel?
> > I don't see any reason why not, but the overall decision will be made by Nico.
Yes they can, as long as there is some assurance that they are headed
for mainline as well. But the Linaro kernel won't help maintain
patches. Long term maintenance should be done in the upstream kernel.
> That's important to market. In case customers of TI, Freescale, ST-E
> are also using SoC from non-member companies, since they are using
> linaro kernel and utilitis well on TI/Freescale/ST-E,
> they want to use the same linaro kernel on non-member chips, if linaro
> accepts and maintains non-member patches, then this tree can be useful
> and customers can use the only tree as their platform to support both
> member chips and non-member chips.
> If so, maybe SoC companies don't need to join linaro, but they can get
> the benefit of linaro too. So what's the opinion of Nico?
You should realize that for your patches to be merged into the Linaro
kernel, they must be in a similar state as if you were about to submit
them upstream. Therefore you must have made the effort of making your
code clean already. And once you're there, then you may just post them
for upstream inclusion as well -- that's always our ultimate goal.
The advantage of having those patches also merged into the Linaro kernel
is all about early visibility and exposure. The latest developments
from upstream and the Linaro members are put together, in a kernel that
gets packaged and distributed along with user space components through
the Linaro infrastructure, to test and demonstrate the technology being
worked on without having to wait for the next upstream kernel release.
Of course, if you are not a Linaro member, then you might have more
difficulties keeping up to date with the work being done in the various
groups as your platform won't be covered explicitly by those working
groups, and it won't be supported in the Linaro release. But your
patches would be accepted nevertheless, given that they also are on
their way to be merged upstream.
I hope this helps.
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