[PATCH 5/5] UBUNTU: SAUCE: nvme: Fix erroneous parameter to dma_map_sg_attrs()

[Tim Gardner]

On 11/18/2016 07:09 AM, Seth Forshee wrote:
> On Fri, Nov 18, 2016 at 06:58:08AM -0700, Tim Gardner wrote:
>> On 11/18/2016 06:36 AM, Seth Forshee wrote:
>>> On Wed, Nov 16, 2016 at 07:35:56AM -0700, Tim Gardner wrote:
>>>> BugLink: http://bugs.launchpad.net/bugs/1637565
>>>>
>>>> Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
>>>> ---
>>>>  drivers/nvme/host/pci.c | 3 ++-
>>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
>>>> index 5256448..3931ceb 100644
>>>> --- a/drivers/nvme/host/pci.c
>>>> +++ b/drivers/nvme/host/pci.c
>>>> @@ -623,6 +623,7 @@ static int nvme_map_data(struct nvme_dev *dev, struct request *req,
>>>>  	enum dma_data_direction dma_dir = rq_data_dir(req) ?
>>>>  			DMA_TO_DEVICE : DMA_FROM_DEVICE;
>>>>  	int ret = BLK_MQ_RQ_QUEUE_ERROR;
>>>> +	DEFINE_DMA_ATTRS(attrs);
>>>
>>> You also need this:
>>>
>>>         dma_set_attr(DMA_ATTR_NO_WARN, &attrs);
>>>
>>
>> DMA_ATTR_NO_WARN was not introduced until v4.9-rc1. I think map_sg()
>> expects something from the enumerated set 'enum dma_attr'.
>>
>> I did find an instance of its use in arch/powerpc/kernel/iommu.c where
>> DMA_ATTR_NO_WARN is being queried. I think that is an erroneous backport
>> on my part, but harmless.
> 
> In that case you should just revert
> 7c50722ad76b1b90538912fb84e2c3e206fab327 (nvme: use the DMA_ATTR_NO_WARN
> attribute).
> 

But that'll break powerpc. I'm inclined to leave it alone since it
really is harmless. Or address it in another bug.

rtg
-- 
Tim Gardner tim.gardner at canonical.com