Re: mcs7830 usb net: "scheduling while atomic" danger?

From: Thomas Gleixner
Date: Mon Jan 18 2010 - 16:38:48 EST


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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