[U-Boot] [PATCH 4/5] include: dma: Update the function description for dma_memcpy
Chee, Tien Fong
tien.fong.chee at intel.com
Mon Jun 4 07:14:05 UTC 2018
On Fri, 2018-06-01 at 08:25 -0600, Simon Glass wrote:
> Hi,
>
> On 31 May 2018 at 02:08, <tien.fong.chee at intel.com> wrote:
> >
> > From: Tien Fong Chee <tien.fong.chee at intel.com>
> >
> > Update the dma_memcpy description on return argument for DMA330
> > driver.
> >
> > Signed-off-by: Tien Fong Chee <tien.fong.chee at intel.com>
> > ---
> > include/dma.h | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/dma.h b/include/dma.h
> > index 0a0c9dd..b825c1e 100644
> > --- a/include/dma.h
> > +++ b/include/dma.h
> > @@ -79,8 +79,8 @@ int dma_get_device(u32 transfer_type, struct
> > udevice **devp);
> > * @dst - destination pointer
> > * @src - souce pointer
> > * @len - data length to be copied
> > - * @return - on successful transfer returns no of bytes
> > - transferred and on failure return error code.
> > + * @return - on successful transfer returns no of bytes or
> > zero(for DMA330)
> > + * transferred and on failure return error code.
> This is a public API so you cannot change it just for one device. You
> can change the API for everyone if you like.
>
> But why would it want to return 0?
>
Because we only able to check the DMA tranferring status, full transfer
or failed. I can return the len argument user set if full tranfer is
finished.
> >
> > */
> > int dma_memcpy(struct udevice *dev, void *dst, void *src, size_t
> > len);
> >
> > --
> > 2.2.0
> >
> Regards,
> Simon
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