Re: gm45 intel gfx can generate non-MSI irq# in MSI mode (was Re:[PATCH] drm/i915: stop using GMBUS IRQs on Gen4 chips (was Re: [3.9-rc1]irq 16: nobody cared (was [3.9-rc1] very poor interrupt respo
From: Alan Stern
Date: Tue Mar 19 2013 - 14:19:07 EST
On Tue, 19 Mar 2013, Daniel Vetter wrote:
> > That might be misleading. It's possible that the erroneous IRQs _are_
> > being issued but you're simply not aware of them. If the kernel thinks
> > that no device is using IRQ 16 then it will leave that IRQ disabled.
> I guess I should have phrased it more precisely, but that's exactly
> what I expect is happening on my machine: I don't have anything on
> irq16 (i.e. in non-msi mode the gfx interrupt isn't shared) and hence
> the irq is completely disabled. Which obviously makes it impossible
> for me to reproduce the issue. To test that theory, is there a quick
> way to force-enable a given interrupt, short of just hacking up a 2nd
> dummy irq handler in my driver?
I don't know of any way. In fact, I have been thinking of writing a
test driver module, with a module parameter telling it which IRQ number
to register for. It seems like the sort of thing that would be useful
to have, from time to time.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/