Re: [PATCH] scsi: libsas: fix ata xfer length

[John Garry]

On 19/03/2017 17:21, Martin K. Petersen wrote:
> John Garry <john.garry@xxxxxxxxxx> writes:
>
> John,
>
> > The total ata xfer length may not be calculated properly,
> > in that we do not use the proper method to get an sg element
> > dma length.
> >
> > According to the code comment, sg_dma_len() should be used
> > after dma_map_sg() is called.
> >
> > This issue was found by turning on the SMMUv3 in front of
> > the hisi_sas controller in hip07. Multiple sg elements
> > were being combined into a single element, but the original
> > first element length was being use as the total xfer length.

I should have added this originally to the changelog:
Fixes: ff2aeb1eb64c8a4770a6 ("libata: convert to chained sg")

BTW, I am surprised this issue has not been seen in almost 10 years, but 
we cannot attach a SATA disk when SMMU enabled without it.

Cheers,
John

> Applied to 4.11/scsi-fixes.