Re: DMA error when sg->offset value is greater than PAGE_SIZE in Intel IOMMU

From: Raj, Ashok
Date: Mon Sep 25 2017 - 14:39:40 EST


Hi Casey

Sorry, somehow didn't see this one come by.


On Mon, Sep 25, 2017 at 05:46:40PM +0000, Casey Leedom wrote:
> | From: Robin Murphy <robin.murphy@xxxxxxx>
> | Sent: Wednesday, September 20, 2017 3:12 AM
> |
> | On 20/09/17 09:01, Herbert Xu wrote:
> | >
> | > Harsh Jain <Harsh@xxxxxxxxxxx> wrote:
> | >>
> | >> While debugging DMA mapping error in chelsio crypto driver we
> | >> observed that when scatter/gather list received by driver has
> | >> some entry with page->offset > 4096 (PAGE_SIZE). It starts
> | >> giving DMA error. Without IOMMU it works fine.

Not sure how the page->offset would end up being greater than page-size?

If you have additional traces, please send them by.

Is this a new driver? wondering how we didn't run into this?


Cheers,
Ashok