[PATCH] powerpc/vio: dispose of virq mapping on vdevice unregister

[Tyrel Datwyler]

Ping...

Anybody, see any issues with this patch?

-Tyrel

On 09/28/2017 05:19 PM, Tyrel Datwyler wrote:
> When a vdevice is DLPAR removed from the system the vio subsystem doesn't
> bother unmapping the virq from the irq_domain. As a result we have a virq
> mapped to a hardware irq that is no longer valid for the irq_domain. A side
> effect is that we are left with /proc/irq/<irq#> affinity entries, and
> attempts to modify the smp_affinity of the irq will fail.
> 
> In the following observed example the kernel log is spammed by
> ics_rtas_set_affinity errors after the removal of a VSCSI adapter. This is a
> result of irqbalance trying to adjust the affinity every 10 seconds.
> 
> rpadlpar_io: slot U8408.E8E.10A7ACV-V5-C25 removed
> ics_rtas_set_affinity: ibm,set-xive irq=655385 returns -3
> ics_rtas_set_affinity: ibm,set-xive irq=655385 returns -3
> 
> This patch fixes the issue by calling irq_dispose_mapping() on the virq of the
> viodev on unregister.
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Tyrel Datwyler <tyreld at linux.vnet.ibm.com>
> ---
>   arch/powerpc/kernel/vio.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
> index 5f8dcda..a3228d6 100644
> --- a/arch/powerpc/kernel/vio.c
> +++ b/arch/powerpc/kernel/vio.c
> @@ -1577,6 +1577,8 @@ static struct device_attribute vio_dev_attrs[] = {
>   void vio_unregister_device(struct vio_dev *viodev)
>   {
>   	device_unregister(&viodev->dev);
> +	if (viodev->family == VDEVICE)
> +		irq_dispose_mapping(viodev->irq);
>   }
>   EXPORT_SYMBOL(vio_unregister_device);
>