Re: [PATCH net-next v6 00/11] net: ethernet: ti: add networking support for k3 am65x/j721e soc

From: Nick Desaulniers <ndesaulniers@google.com>
To: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Will Deacon <will@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Arnd Bergmann <arnd@arndb.de>,
	devicetree@vger.kernel.org, kishon@ti.com,
	Jakub Kicinski <kuba@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	m-karicheri2@ti.com, Network Development <netdev@vger.kernel.org>,
	nsekhar@ti.com, Olof Johansson <olof@lixom.net>,
	olteanv@gmail.com, peter.ujfalusi@ti.com,
	Rob Herring <robh@kernel.org>,
	rogerq@ti.com, t-kristo@ti.com,
	clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH net-next v6 00/11] net: ethernet: ti: add networking support for k3 am65x/j721e soc
Date: Thu, 2 Apr 2020 10:27:04 -0700	[thread overview]
Message-ID: <CAKwvOdk4H052Y=t4_XXy=rMV=CUYPNhb5CN6x8-dBTNaTt3aPA@mail.gmail.com> (raw)
In-Reply-To: <adc2aa08-60e2-cdc3-6b5b-6d96f8805c44@ti.com>

On Thu, Apr 2, 2020 at 4:05 AM Grygorii Strashko
<grygorii.strashko@ti.com> wrote:
>
>
>
> On 02/04/2020 12:42, Will Deacon wrote:
> > On Wed, Apr 01, 2020 at 03:35:00PM -0700, Nick Desaulniers wrote:
> >>>> I think the ARM64 build is now also broken on Linus' master branch,
> >>>> after the net-next merge? I am not quite sure if the device tree
> >>>> patches were supposed to land in mainline the way they did.
> >>>
> >>> There's a fix in my net tree and it will go to Linus soon.
> >>>
> >>> There is no clear policy for dt change integration, and honestly
> >>> I try to deal with the situation on a case by case basis.
> >>
> >> Yep, mainline aarch64-linux-gnu- builds are totally hosed.  DTC fails the build
> >> very early on:
> >> https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/311246218
> >> https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/311246270
> >> There was no failure in -next, not sure how we skipped our canary in the coal
> >> mine.
> >
> > Yes, one of the things linux-next does a really good job at catching is
> > build breakage so it would've been nice to have seen this there rather
> > than end up with breakage in Linus' tree :(
> >
> > Was the timing just bad, or are we missing DT coverage or something else?
>
> It seems issue was not caught in -next because the patch that fixes the issue was already in -next
> before this series was pushed.
>
> Sorry for the mess again.

No worries, it's just worthwhile to study failures.  So IIUC, in this case:
mainline was 5.6
the broken patch was merged in 5.7 merge window
a fix was already in -next, but not slated for the new merge window.
(Maybe scheduled for 5.8?)

So it sounds like it can be dangerous to have 2 branches from 1 tree
flow into -next, as the branch meant for a later release can mask
failures in pull requests for the earlier release?

Do we know what and where the fix currently is?
Can we make sure it's sent to Linus for 5.7-rc1? (Or sooner?)
-- 
Thanks,
~Nick Desaulniers