Re: [PATCH] dma-debug: hash_bucket_find needs to allow for offsetswithin an entry (v2)

From: Roedel, Joerg
Date: Wed Aug 10 2011 - 09:32:15 EST

On Mon, Aug 08, 2011 at 03:13:54PM -0400, Neil Horman wrote:
> dma-debug: hash_bucket_find needs to allow for offsets within an entry (v2)
> Summary:
> Users of the pci_dma_sync_single_* api allow users to sync address ranges within
> the range of a mapped entry (i.e. you can dma map address X to dma_addr_t A and
> then pci_dma_sync_single on dma_addr_t A+1. The dma-debug library however
> assume dma syncs will always occur using the base address of a mapped region,
> and uses that assumption to find entries in its hash table. Since thats often
> (but not always the case), the dma debug library can give us false errors about
> missing entries, which are reported as syncing of memory not allocated by the
> driver. This was noted in the cxgb3 driver as this error:

Hi Neil,

thanks for your patch. Im out-of-office this week and traveling next
week. So it may take a couple of days until I can take an in-depth look
at it. But I get to it as soon as I can :-)



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