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Message-ID: <235c80fc-3f1b-a9c9-6364-6f50ee45b21b@arinc9.com>
Date:   Fri, 21 Apr 2023 21:25:39 +0300
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Subject: Re: [RFC PATCH net-next 08/22] net: dsa: mt7530: change
 p{5,6}_interface to p{5,6}_configured
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From:   =?UTF-8?B?QXLEsW7DpyDDnE5BTA==?= <arinc.unal@arinc9.com>
To:     Daniel Golle <daniel@makrotopia.org>
Cc:     Sean Wang <sean.wang@mediatek.com>,
        Landen Chao <Landen.Chao@mediatek.com>,
        DENG Qingfang <dqfext@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@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>,
        Russell King <linux@armlinux.org.uk>,
        Richard van Schagen <richard@routerhints.com>,
        Richard van Schagen <vschagen@cs.com>,
        Frank Wunderlich <frank-w@public-files.de>,
        erkin.bozoglu@xeront.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
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On 21.04.2023 21:20, Arınç ÜNAL wrote:
> On 21.04.2023 21:17, Arınç ÜNAL wrote:
>> On 21.04.2023 20:28, Daniel Golle wrote:
>>> On Fri, Apr 21, 2023 at 05:36:34PM +0300, arinc9.unal@gmail.com wrote:
>>>> From: Arınç ÜNAL <arinc.unal@arinc9.com>
>>>>
>>>> The idea of p5_interface and p6_interface pointers is to prevent
>>>> mt753x_mac_config() from running twice for MT7531, as it's already 
>>>> run with
>>>> mt753x_cpu_port_enable() from mt7531_setup_common(), if the port is 
>>>> used as
>>>> a CPU port.
>>>>
>>>> Change p5_interface and p6_interface to p5_configured and 
>>>> p6_configured.
>>>> Make them boolean.
>>>>
>>>> Do not set them for any other reason.
>>>>
>>>> The priv->p5_intf_sel check is useless as in this code path, it will 
>>>> always
>>>> be P5_INTF_SEL_GMAC5.
>>>>
>>>> There was also no need to set priv->p5_interface and 
>>>> priv->p6_interface to
>>>> PHY_INTERFACE_MODE_NA on mt7530_setup() and mt7531_setup() as they 
>>>> would
>>>> already be set to that when "priv" is allocated. The pointers were 
>>>> of the
>>>> phy_interface_t enumeration type, and the first element of the enum is
>>>> PHY_INTERFACE_MODE_NA. There was nothing in between that would 
>>>> change this
>>>> beforehand.
>>>>
>>>> Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
>>>> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
>>>
>>> NACK. This assumes that a user port is configured exactly once.
>>> However, interface mode may change because of mode-changing PHYs (e.g.
>>> often using Cisco SGMII for 10M/100M/1000M but using 2500Base-X for
>>> 2500M, ie. depending on actual link speed).
>>>
>>> Also when using SFP modules (which can be hotplugged) the interface
>>> mode may change after initially setting up the driver, e.g. when SFP
>>> driver is loaded or a module is plugged or replaced.
>>
>> I'm not sure I understand. pX_configured would be set to true only 
>> when the port is used as a CPU port. mt753x_mac_config() should run 
>> for user or DSA ports more than once, if needed.
> 
> Looking at this again, once pX_interface is true, the check will prevent 
> even user or DSA ports to be configured again. What about setting 
> pX_interface to false after mt753x_mac_config() is run?

On a third thought, pX_interface will never be true for the port if it's 
a user or DSA port so this should not be a problem at all.

Arınç