Re: [PATCH v2 3/3] net: netcp: rework the code for get/set sw_data in dma desc

From: Arnd Bergmann
Date: Fri Feb 19 2016 - 17:25:25 EST


On Friday 19 February 2016 17:21:57 Murali Karicheri wrote:
> >> get_pkt_info(&dma_buf, &tmp, &dma_desc, ndesc);
> >> - get_sw_data((u32 *)&buf_ptr, &buf_len, ndesc);
> >> + /* warning!!!! We are retrieving the virtual ptr in the sw_data
> >> + * field as a 32bit value. Will not work on 64bit machines
> >> + */
> >> + buf_ptr = (void *)GET_SW_DATA0(ndesc);
> >> + buf_len = (int)GET_SW_DATA1(desc);
> >
> > I would have abstracted the retrieval of a pointer again,
> > and added the comment in the helper function once, it doesn't
> > really need to be duplicated everywhere.
> >
> Arnd,
>
> I thought about it to add it to the API. API currently set buffer
> and ptr. It would be an issue only if store/retrieve ptr in/from the sw_data.
> So for the comment to be really useful to someone who is changing the code,
> doesn't it make sense to add it at the point of invocation as done in this
> patch? No?
>

Up to you, it was just an idea and you have my Ack either way.

Arnd