Re: [PATCH net] net: mvneta: fix operation for 64K PAGE_SIZE

[Marcin Wojtas <mw@semihalf.com>]

Hi David,

niedz., 16 gru 2018 o 21:41 David Miller <davem@davemloft.net> napisał(a):
>
> From: Marcin Wojtas <mw@semihalf.com>
> Date: Tue, 11 Dec 2018 13:56:49 +0100
>
> > Recent changes in the mvneta driver reworked allocation
> > and handling of the ingress buffers to use entire pages.
> > Apart from that in SW BM scenario the HW must be informed
> > via PRXDQS about the biggest possible incoming buffer
> > that can be propagated by RX descriptors.
> >
> > The BufferSize field was filled according to the MTU-dependent
> > pkt_size value. Later change to PAGE_SIZE broke RX operation
> > when usin 64K pages, as the field is simply too small.
> >
> > This patch conditionally limits the value passed to the BufferSize
> > of the PRXDQS register, depending on the PAGE_SIZE used.
> > On the occasion remove now unused frag_size field of the mvneta_port
> > structure.
> >
> > Fixes: 562e2f467e71 ("net: mvneta: Improve the buffer allocation method for SWBM")
> > Signed-off-by: Marcin Wojtas <mw@semihalf.com>
>
> The discussion died on this, but the bug should be fixed.
>
> So in the short term I am applying this and queueing it up for v4.19
> -stable.
>
> Thanks.

Thanks. Indeed, the patch is valid as a fix for current version of SW
BM. However, because this concept is broken, I will rework it and
submit patch/patches some time early 2019.

Best regards,
Marcin