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Date:   Wed, 2 Nov 2022 01:03:08 +0000
From:   Daniel Golle <daniel@makrotopia.org>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
        Sean Wang <sean.wang@mediatek.com>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] net: ethernet: mediatek: ppe: add support for flow
 accounting
Message-ID: <Y2HBzEdmiKK9IPFK@makrotopia.org>
References: <Y2G9ANkdaaENNnOd@makrotopia.org>
 <Y2G/CaPrTVsYeGWB@lunn.ch>
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Hi Andrew,

On Wed, Nov 02, 2022 at 01:51:21AM +0100, Andrew Lunn wrote:
> On Wed, Nov 02, 2022 at 12:42:40AM +0000, Daniel Golle wrote:
> > The PPE units found in MT7622 and newer support packet and byte
> > accounting of hw-offloaded flows. Add support for reading those
> > counters as found in MediaTek's SDK[1].
> > 
> > [1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/bc6a6a375c800dc2b80e1a325a2c732d1737df92
> > Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> 
> Sorry, but NACK.
> 
> You have not explained why doing this correctly via ethtool -S cannot
> be done. debugfs is a vendor crap way of doing this.

The debugfs interface is pre-existing and **in addition** to the
standard Linux interfaces which are also provided. It is true that
the debugfs interface in this case doesn't provide much additional
value apart from having the counter listed next to the hardware-
specific hashtable keys. As the debugfs interface for now aims to
be as complete as possible, naturally there is some redundance of
things which can also be accessed using other (standard) interfaces.

Anyway. See function mtk_flow_offload_stats which now also reports
counters.


Cheers


Daniel