From: "Raj, Ashok" <ashok.raj@intel.com>
Subject: Re: DMA error when sg->offset value is greater than PAGE_SIZE in
 Intel IOMMU
Date: Thu, 28 Sep 2017 06:05:50 -0700
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Cc: Casey Leedom <leedom@chelsio.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
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To: Harsh Jain <Harsh@chelsio.com>
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Thanks for trying that Harsh. 

sp_off turns of super page support. Which this mode, do you still see offsets greater than 4k?

On Thu, Sep 28, 2017 at 07:08:21PM +0530, Harsh Jain wrote:
> 
> 
> Today I tried with "Intel_iommu=sp_off" boot option. Traffic runs without any error for more than 1 hrs. What magic this option did? :)

Cheers,
Ashok