Re: "do_IRQ: 0.89 No irq handler for vector (irq -1)"

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, October 12, 2010, Jesse Barnes wrote:
> On Mon, 11 Oct 2010 15:48:26 -0700
> Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> 
> > On Fri, 8 Oct 2010 21:46:50 +1000
> > Dave Airlie <airlied@gmail.com> wrote:
> > > Not sure how best to fix, I can workaround by calling
> > > pci_set_power_state(PCI_D0) in the drm drivers, but I sorta thing the
> > > PCI layer should take care of this.
> > 
> > So I think we *should* be able to call pci_disable_device at remove
> > time.  But as you say, some platforms may not correctly re-route VGA
> > space to an existing device or disable it properly when we do that.
> > AFAICT x86 will be ok here though (seems to work ok locally too).
> 
> Just tested this some more, and I think it's the right thing to do in
> the KMS case at least.  When we load a KMS driver it takes over the gfx
> device and nothing can assume anything about VGA state unless using the
> VGA arbiter.  So calling pci_disable_device() in the shutdown path of a
> KMS driver shouldn't make things any worse, and will work around this
> issue.
> 
> Doing so in the non-KMS case violates some PC assumptions though, in
> that things like vgacon and the BIOS will assume VGA memory is still
> around, which on some platforms pci_disable_device() may affect (I only
> checked the x86 implementation).
> 
> > That said, it seems like we should update the current device state at
> > load time as well, once we've matched the driver it seems like there
> > should be no harm.
> > 
> > Rafael, what do you think?  Would having the correct power state at
> > load time cause any trouble with other PM code?  I know we've had
> > issues with setting it explicitly in the past...
> 
> So we should probably make pci_enable_device pick up the current state
> as well, instead of assuming it's unknown just because the enable count
> was non-zero (which as Dave points out, can be affected by sysfs writes
> too).
> 
> The only downside I can think of there is that if the device is already
> enabled, we generally have to assume another driver owns it, and who
> knows if the device is actually alive enough to read the current state
> from.  But I think we handle those errors ok too, so pulling it out
> should be safe.

I remember trying to do something like this and it didn't play well with the
initialization.  Still, I didn't do that in pci_enable_device(), so I can't say
for sure at the moment.  I _think_ it will be fine, though.

Thanks,
Rafael