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From: Greg KH <greg@kroah.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	linux-kernel@vger.kernel.org, linux-rt@pengutronix.de,
	"Ian Abbott" <abbotti@mev.co.uk>,
	"Frank Mori Hess" <fmhess@users.sourceforge.net>
Subject: Re: [PATCH -rt] disable building all staging drivers
Date: Tue, 23 Jun 2009 08:17:01 -0700	[thread overview]
Message-ID: <20090623151701.GD30806@kroah.com> (raw)
In-Reply-To: <alpine.LFD.2.00.0906231216220.2767@localhost.localdomain>

On Tue, Jun 23, 2009 at 01:24:19PM +0200, Thomas Gleixner wrote:
> On Mon, 22 Jun 2009, Greg KH wrote:
> > > 17:02:43 E: ERROR: "there_is_no_init_MUTEX_LOCKED_for_RT_semaphores" [drivers/staging/rt2870/rt2870sta.ko] undefined!
> > 
> > What needs to be done in the rt2870 driver to resolve this issue?
> 
> It looks like the semaphores are used to wait for an event. There are
> actually 3 of those:
> 
> 	 init_MUTEX_LOCKED(&(pAd->mlme_semaphore));
> 	 init_MUTEX_LOCKED(&(pAd->RTUSBCmd_semaphore));
> 	 init_MUTEX_LOCKED(&(pAd->RTUSBTimer_semaphore));
> 
> All are used in kernel threads which wait with down_interruptible() on
> them. The up() calls are in some completely non obvious places.
> 
> I had a look into the timer one. The semaphore is the least thing you
> need to worry about there. The open coded timer list management and
> the thread which does timer polling for some obscure reason are the
> things which need to be fixed in the first place. Once this is cleaned
> up the semaphore will be gone anyway.
> 
> But, after looking into that code I really have to ask you whether you
> are serious about fixing it instead of rewriting it from scratch and
> just keep the code as is for reference to the hardware details.

That is exactly what the code is there for.  There are other groups
rewriting these drivers from scratch, and hopefully they will be done in
a kernel release or two and then these drivers can go away.

If, in the mean time, you don't want them to be built for -rt kernels,
just send me a Kconfig patch for the individual drivers, not for the
whole of the staging tree.

thanks,

greg k-h

  reply	other threads:[~2009-06-23 15:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-13 21:38 [PATCH -rt] disable building all staging drivers Uwe Kleine-König
2009-06-14 11:28 ` Greg KH
2009-06-14 12:34   ` Thomas Gleixner
2009-06-14 23:00   ` Uwe Kleine-König
2009-06-14 23:04     ` Greg KH
2009-06-22 15:15     ` Uwe Kleine-König
2009-06-22 17:19       ` Greg KH
2009-06-22 18:06         ` Daniel Walker
2009-06-22 20:51           ` Greg KH
2009-06-23 11:24         ` Thomas Gleixner
2009-06-23 15:17           ` Greg KH [this message]
2009-06-23 15:39             ` Thomas Gleixner
2009-09-07 16:20       ` [RT + staging] buildfailures Uwe Kleine-König
2009-09-08 18:11         ` Greg KH

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