Re: [PATCH net v2 2/7] net: dsa: mt7530: fix trapping frames with multiple CPU ports on MT7530

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: "Arınç ÜNAL" <arinc.unal@arinc9.com>
Cc: Vladimir Oltean <olteanv@gmail.com>,
	Daniel Golle <daniel@makrotopia.org>,
	Landen Chao <Landen.Chao@mediatek.com>,
	DENG Qingfang <dqfext@gmail.com>,
	Sean Wang <sean.wang@mediatek.com>, Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.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>,
	AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>,
	Frank Wunderlich <frank-w@public-files.de>,
	Bartel Eerdekens <bartel.eerdekens@constell8.be>,
	mithat.guner@xeront.com, erkin.bozoglu@xeront.com,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH net v2 2/7] net: dsa: mt7530: fix trapping frames with multiple CPU ports on MT7530
Date: Tue, 13 Jun 2023 19:29:18 +0100	[thread overview]
Message-ID: <ZIi1fixnNqj9Gfcg@shell.armlinux.org.uk> (raw)
In-Reply-To: <edcbe326-c456-06ef-373b-313e780209de@arinc9.com>

On Tue, Jun 13, 2023 at 08:58:33PM +0300, Arınç ÜNAL wrote:
> On 13.06.2023 20:39, Vladimir Oltean wrote:
> > On Tue, Jun 13, 2023 at 08:30:28PM +0300, Arınç ÜNAL wrote:
> > > That fixes port 5 on certain variants of the MT7530 switch, as it was
> > > already working on the other variants, which, in conclusion, fixes port 5 on
> > > all MT7530 variants.
> > 
> > Ok. I didn't pay enough attention to the commit message.
> > 
> > > And no, trapping works. Having only CPU port 5 defined on the devicetree
> > > will cause the CPU_PORT bits to be set to port 5. There's only a problem
> > > when multiple CPU ports are defined.
> > 
> > Got it. Then this is really not a problem, and the commit message frames
> > it incorrectly.
> 
> Actually this patch fixes the issue it describes. At the state of this
> patch, when multiple CPU ports are defined, port 5 is the active CPU port,
> CPU_PORT bits are set to port 6.

Maybe it's just me being dumb, but I keep finding things difficult to
understand, such as the above paragraph.

It sounds like you're saying that _before_ this patch, port 5 is the
active CPU port, but the CPU_PORT *FIELD* NOT BITS are set such that
port 6 is the active CPU port. Therefore, things are broken, and this
patch fixes it.

Or are you saying that after this patch is applied, port 5 is the
active CPU port, but the CPU_PORT *FIELD* is set to port 6. If that's
true, then I've no idea what the hell is going on here because it
seems to be senseless.

I think at this point I just give up trying to understand what the
hell these patches are trying to do - in my opinion, the commit
messages are worded attrociously and incomprehensively.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel