Re: [patch] sparc64: enable IRQs on error paths

[Sam Ravnborg <sam@ravnborg.org>]

Hi Dan.

On Fri, Nov 25, 2016 at 02:12:51PM +0300, Dan Carpenter wrote:
> There are several error paths where we should enable IRQs but we don't.
> 
> Fixes: bb620c3d3925 ("sparc: Make sparc64 use scalable lib/iommu-common.c functions")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Please use a more descriptive subject such as:
sparc64: restore irq in error paths in iommu

> ---
> Not tested.
> 
> diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
> index 06981cc7..274df7a 100644
> --- a/arch/sparc/kernel/pci_sun4v.c
> +++ b/arch/sparc/kernel/pci_sun4v.c
> @@ -230,12 +230,16 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
>  
>  	for (n = 0; n < npages; n++) {
>  		long err = iommu_batch_add(first_page + (n * PAGE_SIZE), mask);
> -		if (unlikely(err < 0L))
> +		if (unlikely(err < 0L)) {
> +			local_irq_restore(flags);
>  			goto iommu_map_fail;
> +		}
>  	}

Locate all cleanup after the iommu_map_fail label.

As it is now the irq_restore is on the error site
and the free() is at the error label.

It is very confusing that half of the recovery is in one
place and the other in another place.

	Sam