Messages in this thread | | | From | Ilias Apalodimas <> | Date | Thu, 23 Sep 2021 13:02:05 +0300 | Subject | Re: [PATCH net-next 1/7] page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA |
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Hi Jesper,
On Thu, 23 Sept 2021 at 12:33, Jesper Dangaard Brouer <jbrouer@redhat.com> wrote: > > > On 22/09/2021 11.41, Yunsheng Lin wrote: > > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > > index 1a6978427d6c..a65bd7972e37 100644 > > --- a/net/core/page_pool.c > > +++ b/net/core/page_pool.c > > @@ -49,6 +49,12 @@ static int page_pool_init(struct page_pool *pool, > > * which is the XDP_TX use-case. > > */ > > if (pool->p.flags & PP_FLAG_DMA_MAP) { > > + /* DMA-mapping is not supported on 32-bit systems with > > + * 64-bit DMA mapping. > > + */ > > + if (sizeof(dma_addr_t) > sizeof(unsigned long)) > > + return -EINVAL; > > As I said before, can we please use another error than EINVAL. > We should give drivers a chance/ability to detect this error, and e.g. > fallback to doing DMA mappings inside driver instead. > > I suggest using EOPNOTSUPP 95 (Operation not supported).
I am fine with both. In any case though the aforementioned driver can just remove PP_FLAG_DMA_MAP and do it's own mappings.
Regards /Ilias > > -Jesper >
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