Messages in this thread | | | Date | Mon, 18 Jan 2010 22:35:23 +0100 (CET) | From | Julia Lawall <> | Subject | Re: mcs7830 usb net: "scheduling while atomic" danger? |
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On Mon, 18 Jan 2010, Arnd Bergmann wrote:
> On Monday 18 January 2010, Julia Lawall wrote: > > On Mon, 18 Jan 2010, Andreas Mohr wrote: > > > > > > Forgive me, but doesn't that mutex_lock()/msleep() (ab)use mean > > > risking a "scheduling while atomic"? > > > (such as discussed in e.g. > > > http://search.luky.org/linux-kernel.2004/msg92817.html ) > > > > > > > > > And, if that is the case, shouldn't all such cases simply be killed for > > > good via a capable semantic patch? > > > > The semantic match shown below finds 55 matches. All but two involve > > mutex_lock. Those are in the file > > /var/linuxes/linux-next/drivers/usb/host/ehci-hub.c > > in the functions ehci_bus_suspend and ehci_hub_control. > > That code looks indeed broken as was added las July as part of 331ac6b288d9 > "USB: EHCI: Add Intel Moorestown EHCI controller HOSTPCx extensions and > support phy low power mode". The reason that this hasn't triggered is > probably the lack of Moorestown machines in the field.
The fix is just msleep -> mdelay?
julia
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