Re: [PATCH 2/2] drm/nouveau: Check that the device is enabled before processing interrupt

Dave Airlie
2011-05-04T03:50:22Z

On Mon, May 2, 2011 at 10:49 AM, Alex Williamson
<alex.williamson@redhat.com> wrote:
> We're likely to be sharing an interrupt line with other devices,
> which means our handler might get called after we've turned off
> the device via vga switcheroo.  This can lead to all sorts of
> badness, like nv04_fifo_isr() spewing "PFIFO still angry after
> 100 spins, halt" to the console before the system enters a hard
> hang.
>
> We can avoid this by simply checking if the device is still
> enabled before processing an interrupt.  To avoid races, flush
> any inflight interrupts using synchronize_irq().  Note that
> since pci_intx() is called after pci_save_state(),
> pci_restore_state() will automatically re-enable INTx.

I still think we should just need the synchronize_irq followed by a
check in the irq handler for all fs,

or is there a race there I'm missing?

Dave.