Date: Mon, 18 Jan 2010 22:38:34 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Julia Lawall <julia@diku.dk>
cc: Andreas Mohr <andi@lisas.de>, linux-kernel@vger.kernel.org,
       Greg KH <greg@kroah.com>
Subject: Re: mcs7830 usb net: "scheduling while atomic" danger?
In-Reply-To: <Pine.LNX.4.64.1001182229360.30446@ask.diku.dk>
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References: <20100118184942.GA10171@rhlx01.hs-esslingen.de> <Pine.LNX.4.64.1001182206190.30446@ask.diku.dk> <alpine.LFD.2.00.1001182219580.2906@localhost.localdomain> <Pine.LNX.4.64.1001182229360.30446@ask.diku.dk>
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On Mon, 18 Jan 2010, Julia Lawall wrote:
> On Mon, 18 Jan 2010, Thomas Gleixner wrote:
> 
> > Julia,
> > 
> > On Mon, 18 Jan 2010, Julia Lawall wrote:
> > > On Mon, 18 Jan 2010, Andreas Mohr wrote:
> > >
> > > The semantic match shown below finds 55 matches.  All but two involve 
> > > mutex_lock.  Those are in the file 
> > 
> > As I said before the mutex_lock()/msleep() ones are fine. 
> 
> OK, I sem to have missed that message.
> 
> > > /var/linuxes/linux-next/drivers/usb/host/ehci-hub.c
> > > in the functions ehci_bus_suspend and ehci_hub_control.
> > 
> > The msleep in ehci_hub_control() which happens with ehci->lock held
> > and irqs disabled is definitely buggy.
> > 
> > I can't see anything wrong wth the msleep in ehci_bus_suspend() as it
> > is _before_ the spin_lock_irq(&ehci->lock) region.
> 
> There is another one later in the function:
> 
> msleep(5);/* 5ms for HCD enter low pwr mode */
> 
> In my linux-next, it is on line 181.

Ooops, missed that one. Right, that's buggy as well.

Thanks,

	tglx
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