Re: [PATCH 2/2] drm/nouveau: Check that the device is enabled beforeprocessing interrupt
From: Dave Airlie
Date: Tue May 03 2011 - 23:50:25 EST
On Mon, May 2, 2011 at 10:49 AM, Alex Williamson
<alex.williamson@xxxxxxxxxx> 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.
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