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

From: Julia Lawall
Date: Mon Jan 18 2010 - 16:32:58 EST


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.

julia
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