Re: [PATCH net-next v6 3/3] selftests/net: devmem.py: add check_rx_large_niov

Bobby Eshleman <[email protected]> Fri, 31 Jul 2026 15:01:01 -0700
Newsgroups org.kernel.vger.linux-media,org.freedesktop.lists.dri-devel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kernel.vger.netdev
Message-ID <[email protected]>
On Thu, Jul 30, 2026 at 03:14:33PM -0700, Jakub Kicinski wrote:
> On Thu, 30 Jul 2026 14:39:37 -0700 Bobby Eshleman wrote:
> > Poking around, it looks like 231.1.167.0 and above should support
> > everything, so fw should be okay AFAICT.
> > 
> > Looks like the config is missing CONFIG_NET_DEVMEM and CONFIG_UDMABUF?
> 
> Ah, damn, you're right. I grepped for DEVMEM and didn't look closely on
> a hit. Turns out there's a non-NET DEVMEM, too.
> 
> Could you send a patch to add the missing config options to 
> tools/testing/selftests/drivers/net/hw/config ?
> 
> Can be separate or part of this series, doesn't matter.

So NET_DEVMEM and UDMABUF both depend on DMA_SHARED_BUFFER, which is not
user-settable (selected by DMABUF_HEAPS and SYNC_FILE, for example).

Pretty sure UDMABUF is supposed to select it, not depend on.
Documentation/driver-api/dma-buf.rst says any "exporter" should select
it, so I'm going to send that patch over there.

Meanwhile, do we want drivers/net/hw/config to workaround by carrying
something like SYNC_FILE or DMABUF_HEAPS, or wait and see about the
udmabuf kconfig change?

Best,
Bobby