linux-kernel - Re: [PATCH 1/3] PWM: add pwm framework support

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]

Date:	Wed, 7 Dec 2011 09:53:39 +0100
From:	Thierry Reding <thierry.reding@...onic-design.de>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Sascha Hauer <s.hauer@...gutronix.de>,
	Ryan Mallon <rmallon@...il.com>,
	Bill Gatliff <bgat@...lgatliff.com>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	viresh kumar <viresh.kumar@...com>,
	Shawn Guo <shawn.guo@...aro.org>,
	Ryan Mallon <ryan@...ewatersys.com>
Subject: Re: [PATCH 1/3] PWM: add pwm framework support

* Arnd Bergmann wrote:
> On Monday 04 July 2011, Sascha Hauer wrote:
> > On Mon, Jul 04, 2011 at 08:43:23PM +1000, Ryan Mallon wrote:
> >
> > > The fine-grained control api could be added now. pwm_config could be
> > > left as is for the time being (the new api could be a wrapper around it
> > > to start with). Polarity control and interrupt handling apis could also
> > > be defined without affecting the drivers which don't need to implement
> > > them. Multiple channels and the sleeping/non-sleeping api are the more
> > > difficult ones, but at least having some sort of indication about how
> > > these plan to be solved would be useful.
> > 
> > Again, why should we add these *now*? It only raises the chance that
> > there's more discussion.
> 
> My impression is that there are a lot of things that could easily be
> done to improve the state of PWM drivers, but I don't care about the
> order in which they are done. My main issue is the lack of a subsystem
> core driver, which both you and Bill have patches for. It's clear that
> other people have other issues and want to see their problems addressed
> first.
> 
> I also think that the pwm code is simple enough that we don't have
> to worry too much about the order that things are done in. Any patch
> that is making the code better should just get in and not have to
> wait for something else to be completed first.
> 
> What we do need now is a maintainer that can coordinate the patches
> and merge the ones that have been agreed on. Or multiple maintainers.

Hi,

I'm looking at adding DT support for pwm-backlight, and I think a central PWM
API will be required first. Looking through the archives this seems to be the
last activity in that direction. Perhaps we can get the efforts restarted?

I pretty much agree with Arnd and Sascha here in that we should try to get a
basic framework added. Everything else can be added on top later.

Thierry

Content of type "application/pgp-signature" skipped