ACK: [PATCH] iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA

[Colin Ian King]

On 11/09/18 12:00, Paolo Pisati wrote:
> From: Dmitry Osipenko <digetx at gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1783746
> 
> commit 5c5c87411488af3cd082221e567498d813d0fe83 upstream.
> 
> This fixes kernel crashing on NVIDIA Tegra if kernel is compiled in
> a multiplatform configuration and IPMMU-VMSA driver is enabled.
> 
> Cc: <stable at vger.kernel.org> # v3.20+
> Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
> Signed-off-by: Joerg Roedel <jroedel at suse.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> 
> (cherry picked from commit 3245925a8e9c4fb5f2ccb2b7c21d2cb35ce8725a)
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
>  drivers/iommu/ipmmu-vmsa.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
> index 8dce3a9..2435103 100644
> --- a/drivers/iommu/ipmmu-vmsa.c
> +++ b/drivers/iommu/ipmmu-vmsa.c
> @@ -1081,12 +1081,19 @@ static struct platform_driver ipmmu_driver = {
>  
>  static int __init ipmmu_init(void)
>  {
> +	struct device_node *np;
>  	static bool setup_done;
>  	int ret;
>  
>  	if (setup_done)
>  		return 0;
>  
> +	np = of_find_matching_node(NULL, ipmmu_of_ids);
> +	if (!np)
> +		return 0;
> +
> +	of_node_put(np);
> +
>  	ret = platform_driver_register(&ipmmu_driver);
>  	if (ret < 0)
>  		return ret;
> 

Clean cherry pick.

Acked-by: Colin Ian King <colin.king at canonical.com>