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

From: FUJITA Tomonori
Date: Wed Feb 03 2010 - 22:31:46 EST


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>
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