From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roland Dreier <rdreier@cisco.com>
Subject: Re: Any ideas about a crash on reboot with igb and intel_iommu?
Date: Fri, 02 Apr 2010 11:13:03 -0700
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Cc: iommu@lists.linux-foundation.org,
	David Woodhouse <dwmw2@infradead.org>
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So actually I found the following change that went into 2.6.31:

    commit 91615f765a2935b6cbae424b9eee1585ed681ae6
    Author: Jesse Brandeburg <jesse.brandeburg@intel.com>
    Date:   Tue Jun 30 12:45:15 2009 +0000

        igb: fix unmap length bug
        
        driver was mixing NET_IP_ALIGN count bytes in map/unmap calls
        unevenly. Only map the bytes that the hardware might dma into

igb in 2.6.30.y is doing pci_map_single(<some length>) and doing
pci_unmap_single(<some other length>).

However I haven't been able to provoke the crash yet, even by bouncing
an igb interface (with VT-d turned on and with CONFIG_DMAR_DEFAULT_ON enabled).
Does this make sense as the sort of thing that might corrupt the iova
rbtree and lead to a crash in the __free_iova / rb_erase code?

Thanks,
  Roland
-- 
Roland Dreier <rolandd@cisco.com> || For corporate legal information go to:
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