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

From: David Miller
Date: Sun Dec 16 2018 - 15:41:28 EST

From: Marcin Wojtas <mw@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>

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