Re: [stable] [PATCH] uio/gen-pci: don't enable interrupts in ISR

Sebastian Andrzej Siewior
2011-08-23T08:40:14Z

* Greg KH | 2011-08-22 17:49:43 [-0700]:

>> > Cc: Anthony Foiani <anthony.foiani@gmail.com>
>
>Why, it's not fixing a bug that anyone hits, right?

"earlier" the interrupt handler was executed either with interrupts
enabled or disabled if IRQF_DISABLED was specified. Later the latter
become default even if IRQF_DISABLED was not specified. This lead to the
splat Anthony reported because the irq handler was entered with IRQs
disabled and the ISR enabled them via spin_unlock_irq(). My initial
patch simply used spin_unlock_irqrestore() (and its counterpart) to have
the same state as we had.

So the bug Anthony hit was that the interrupts were enabled where they
should not be.

>greg k-h

Sebastian