Re: [GIT PULL] omap changes for v2.6.39 merge window

From: Tony Lindgren <tony@atomide.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	Arnd Bergmann <arnd@arndb.de>, Nicolas Pitre <nico@fluxnic.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	LKML <linux-kernel@vger.kernel.org>,
	David Brown <davidb@codeaurora.org>,
	linux-omap@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window
Date: Wed, 30 Mar 2011 16:28:08 -0700	[thread overview]
Message-ID: <20110330232808.GP18334@atomide.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1103310059531.22418@localhost6.localdomain6>

* Thomas Gleixner <tglx@linutronix.de> [110330 16:11]:
> On Wed, 30 Mar 2011, Tony Lindgren wrote:
> 
> > * Paul E. McKenney <paulmck@linux.vnet.ibm.com> [110330 15:35]:
> > > On Wed, Mar 30, 2011 at 02:54:35PM -0700, Tony Lindgren wrote:
> > > > * Thomas Gleixner <tglx@linutronix.de> [110330 14:07]:
> > > > > 
> > > > > So one person will be not enough, that needs to be a whole team of
> > > > > experienced people in the very near future to deal with the massive
> > > > > tsunami of crap which is targeted at mainline. If we fail to set that
> > > > > up, then we run into a very ugly maintainability issue in no time.
> > > > 
> > > > One thing that will help here and distribute the load is to move
> > > > more things under drivers/ as then we have more maintainers looking
> > > > at the code.
> > > 
> > > In many cases, the ARM SoC vendors will want their people producing the
> > > code, so although moving things to drivers might be a good thing to do,
> > > it won't really increase the number of people involved.  Plus the move
> > > to the drivers subtree would be a problem for devices with tight ties
> > > to the board or SoC.
> > > 
> > > There is work on pushing towards common code, but there is a lot of code
> > > and this will take time and a lot of work.
> > 
> > I agree on the common code part, then even drivers with tight
> > ties to board or SoC become just generic drivers that are easy
> > to review.
> 
> You wish. There is an already existing problem that the identical IP
> cores of peripheral crap are reused accross architectures. And of
> course because it is a different architecture we have two different
> drivers with different issues.
> 
> See: http://marc.info/?l=linux-kernel&m=130041568128164

Yeah that's a problem. And getting people to create generic device
drivers is hard, takes tons of commenting and still needs some hardware
workaround options passed in the platform_data..

> We already fail to detect this on the driver level, so please answer
> the question I asked before: How do you spread the load and scale with
> the amount of shite which is coming in?

Sorry I don't have a solution to that :) I'm struggling with that issue
big time myself.

> The above example is probably not the only one in tree and we will see
> lots of unnoticed instances of drivers dealing with minimal different
> versions of the same IP crappola in the near future simply because the
> vendors claim that their stuff is unique and only works with their
> particular instance of hackery unless we have enough capable people to
> look over this. Whether it's in arch/ or drivers/ it does not
> matter. We are simply not prepared to the amount of crap coming in.

Yes I agree. Tools like checkpatch and sparse don't help with issues
like this.

Tony