linux-kernel - Re: [PATCH v2] pwm-backlight: allow for non-increasing brightness levels

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130926125953.GB2141@ulmo>
Date:	Thu, 26 Sep 2013 14:59:54 +0200
From:	Thierry Reding <thierry.reding@...il.com>
To:	Tomi Valkeinen <tomi.valkeinen@...com>
Cc:	Jingoo Han <jg1.han@...sung.com>, Mike Dunn <mikedunn@...sguy.com>,
	Richard Purdie <rpurdie@...ys.net>,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Grant Likely <grant.likely@...aro.org>,
	Rob Herring <rob.herring@...xeda.com>,
	linux-pwm@...r.kernel.org, linux-fbdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
	Robert Jarzmik <robert.jarzmik@...e.fr>,
	Marek Vasut <marex@...x.de>
Subject: Re: [PATCH v2] pwm-backlight: allow for non-increasing brightness
 levels

On Thu, Sep 26, 2013 at 03:08:22PM +0300, Tomi Valkeinen wrote:
> On 26/09/13 14:51, Thierry Reding wrote:
> > On Thu, Sep 26, 2013 at 01:03:06PM +0300, Tomi Valkeinen wrote:
> > [...]
> >> But if you and Thierry think this version is good, I'll take it.
> > 
> > That sounds like you want to take it through the fbdev tree. Jingoo is
> > listed (along with Richard, but he hasn't been responsive to email for
> > years) as maintainer for the backlight subsystem. Furthermore back at
> 
> Ah, so they are. I just thought it falls under fbdev, as it's under
> drivers/video/ =).
> 
> I don't have any particular "want" to take it through fbdev tree. But I
> can take it.
> 
> > the time when I began working on the PWM subsystem, the backlight sub-
> > system was pretty much orphaned, and pwm-backlight was by far the
> > biggest user of the PWM subsystem. I adopted the driver at the time
> > because it needed to be updated for PWM subsystem changes.
> > 
> > What's the plan going forward? Given the coupling between the PWM
> > subsystem and the pwm-backlight driver it might be useful to keep
> > maintaining it as part of the PWM subsystem. On the other hand, there's
> > some coupling between the driver and the backlight subsystem too.
> 
> And backlight is coupled with fbdev... Which is something I don't like.
> 
> > I have a couple of patches queued up for 3.13 that rework parts of the
> > driver, so it'd be good to know how you guys want to handle this.
> 
> Well. I'm happy if somebody wants to maintain the backlight side. In
> fact, I'd be happy if somebody would start restructuring it totally,
> it's rather messy. The link with fbdev should be removed, and some
> backlight drivers are actually panel drivers. However, perhaps Common
> Display Framework is required until it can be fully cleaned.
> 
> So... For the time being, I'm fine with merging pwm-backlight via any
> tree that works best. I'm presuming here that backlight framework and
> fbdev (for the parts that are relevant for backlight) are not really
> being changed, so there shouldn't be conflicts.

In that case I'll just take it through the PWM tree as I've done for the
past year. I have some other changes planned for the PWM framework for
the near future that'll create dependencies between the PWM tree and the
pwm-backlight driver, so keeping them in one tree will make it easier to
merge them.

Longer term it probably makes sense, as you say, for someone to take
over the backlight subsystem completely and give it the love it could
really use. If Jingoo can do that, it'd be great. Perhaps it'd be a good
idea to remove Richard as maintainer since he's obviously no longer
responding to emails. Keeping him Cc'ed on all patches is just
pointless.

Thierry

Content of type "application/pgp-signature" skipped