Re: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg APIdescription

From: James Bottomley
Date: Wed Feb 03 2010 - 22:34:47 EST


On Thu, 2010-02-04 at 12:31 +0900, FUJITA Tomonori wrote:
> On Wed, 03 Feb 2010 19:21:23 -0800 (PST)
> David Miller <davem@xxxxxxxxxxxxx> wrote:
>
> > From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> > Date: Thu, 4 Feb 2010 12:13:22 +0900
> >
> > > This adds the description of the following eight function:
> > >
> > > dma_sync_single_for_cpu
> > > pci_dma_sync_single_for_cpuvoid
> > ^^^^
> >
> > That "void" is probably some cut and paste error :-)
>
> Oops.
>
>
> > > dma_sync_single_for_device
> > > pci_dma_sync_single_for_device
> > > dma_sync_sg_for_cpu
> > > pci_dma_sync_sg_for_cpu
> > > dma_sync_sg_for_device
> > > pci_dma_sync_sg_for_device
> > >
> > > It was unclear that the API permits a partial sync (some network
> > > drivers already do though). I made it clear that the sync_single API
> > > can do a partial sync but the sync_sg API can't.
> > >
> > > We could do a partial sync with the sync_sg too, however, it's
> > > difficult for driver writers to correctly use the sync_sg API for a
> > > partial sync since the scatterlists passed in to the mapping API can
> > > be modified. It's unlikely that driver writers want to do a partial
> > > sync with the sync_sg API (because the sync_sg API are usually used
> > > for block drivers). So I think that it's better to forbid a partial
> > > sync with the sync_sg API.
> > >
> > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> >
> > Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
>
> Thanks,
>
> I found other two typos in the commit log so here's the update.
>
> =
> From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> Subject: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg API description
>
> This adds the description of the following eight function:
>
> dma_sync_single_for_cpu
> pci_dma_sync_single_for_cpu
> dma_sync_single_for_device
> pci_dma_sync_single_for_device
> dma_sync_sg_for_cpu
> pci_dma_sync_sg_for_cpu
> dma_sync_sg_for_device
> pci_dma_sync_sg_for_device
>
> It was unclear that the API permits a partial sync (some network
> drivers already do though). I made it clear that the sync_single API
> can do a partial sync but the sync_sg API can't.
>
> We could do a partial sync with the sync_sg API too, however, it's
> difficult for driver writers to correctly use the sync_sg API for a
> partial sync since the scatterlists passed in to the mapping API can't
> be modified. It's unlikely that driver writers want to do a partial
> sync with the sync_sg API (because the sync_sg API are usually used
> for block drivers). So I think that it's better to forbid a partial
> sync with the sync_sg API.
>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Cc: James Bottomley <James.Bottomley@xxxxxxx>

For what it's worth, you can add my acked by to both patches too.

James


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