Re: "irq/matrix: Spread interrupts on allocation" breaks nouveau in mainline kernel

From: Lyude Paul
Date: Wed Jan 24 2018 - 12:49:17 EST


Hi, please ignore the warning: it happens before and after the regressing
commit (I didn't actually mean to include it on the log I gave here, whoops).
As for how I determined nouveau is getting assigned the same IRQ vector as
another device, I checked using /sys/kernel/debug/irq. Additionally; when
nouveau does initialize properly after resume (e.g. after reverting this
patch) I see it get assigned a seperate vector from the other devices.

On Wed, 2018-01-24 at 13:52 +0100, Thomas Gleixner wrote:
> On Tue, 23 Jan 2018, Lyude Paul wrote:
>
> > JFYI: I confirmed this patch is definitely broken. I'm seeing nouveau get
> > assigned the same MSI vector as another device on the system, which would
> > explain why interrupts suddenly stop working. I'll keep looking into it
> > further
> > tomorrow.
>
> How did you determine that it is the same MSI vector as another device?
>
> Thanks,
>
> tglx
>
--
Cheers,
Lyude Paul