[Ksummit-discuss] [LTSI-dev] [Stable kernel] feature backporting collaboration

Bird, Timothy Tim.Bird at am.sony.com
Thu Sep 8 18:33:16 UTC 2016


> -----Original Message-----
> From: ltsi-dev-bounces at lists.linuxfoundation.org [mailto:ltsi-dev-
> bounces at lists.linuxfoundation.org] On Behalf Of NeilBrown
> Sent: Monday, September 05, 2016 3:44 PM
> To: Mark Brown <broonie at kernel.org>
> Cc: ltsi-dev at lists.linuxfoundation.org; ksummit-
> discuss at lists.linuxfoundation.org; Levin, Alexander
> <alexander.levin at verizon.com>; James Bottomley
> <James.Bottomley at HansenPartnership.com>
> Subject: Re: [LTSI-dev] [Ksummit-discuss] [Stable kernel] feature backporting
> collaboration
> 
> On Mon, Sep 05 2016, Mark Brown wrote:
> 
> > [ Unknown signature status ]
> > On Mon, Sep 05, 2016 at 11:45:52AM +1000, NeilBrown wrote:
> >> On Sat, Sep 03 2016, Bird, Timothy wrote:
> >
> >> > Where we are now with some of these SoCs is at millions of lines of
> >> > code out-of-tree.  It's being reduced, slowly, but there are still
> >> > significant areas where the mainline kernel just doesn't have the
> >> > support needed for shipping product. My pet peeve is support for
> >> > charging over USB, where Linaro has had a patch set
> >> > being stalled and/or ignored by the USB maintainer for 2 years!!
> >
> >> Do you have a link to that?  I have an interest in charging over USB.
> >
> > This is it:
> >
> >     https://lkml.org/lkml/2016/7/1/35
> >
> > it's been more like one year than two and there has been progress but
> > there's also been an awful lot of latency in the process too.
> 
> Really?  That is worthy of a "pet peeve"?
> The patch set does highlight an important area of missing functionality,
> but doesn't (IMO) display much understanding of the problem space.  I'm
> not surprised it hasn't made progress.

First - thanks for responding to the patch.  I'm hopeful it will see movement.
My "pet peeve" (which *is* a bit histrionic, I suppose) is not so much about this
individual patch (though IMHO it's taken longer to get worked out than it should have).
Rather, I find it shocking that the mainline kernel is missing such a fundamental
feature that is critical to mobile devices.  I brought this up at the kernel summit
last year (so it's not a new rant for me).  But basically, one can not run a mainline
kernel on any phone that I'm aware of, and charge the device.

This means that hobbyists are locked out of experimenting with mainline on their
devices (unless they have the fortitude to manually swap batteries, or switch to
a vendor kernel when they need to charge).  IMHO this is just too much of a burden.
I mean, you might expect that some functionality of the phone might be missing if
you went all-mainline, or pure open source (like proprietary camera modules, or NFC
support).  You'll probably not have access to trivial things like the touch screen or 
display ;-).  But sheesh - to not have your device last longer than a few hours before
you have to do some kludgy work-around, if you want to use mainline on it?
That's retarded.

IMHO this is blocking SoC mainlining efforts by non-vendor people more than any other
single issue.

</rant>
 -- Tim


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