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Message-ID: <2ad1f55c-f361-4439-9174-6af1bb429d55@linux.intel.com>
Date: Fri, 2 Feb 2024 11:00:58 +0800
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Subject: Re: [PATCH net-next v4 06/11] net: stmmac: resetup XPCS according to
 the new interface mode
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>,
 David E Box <david.e.box@linux.intel.com>,
 Hans de Goede <hdegoede@redhat.com>, Mark Gross <markgross@kernel.org>,
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 Voon Wei Feng <weifeng.voon@intel.com>,
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 Lai Peter Jun Ann <jun.ann.lai@intel.com>,
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References: <20240129130253.1400707-1-yong.liang.choong@linux.intel.com>
 <20240129130253.1400707-7-yong.liang.choong@linux.intel.com>
 <ZbjNn+C/VHegH2t7@shell.armlinux.org.uk>
 <9e23671e-788c-4191-bdb4-94915ff7da5a@linux.intel.com>
 <ZbtYaXkNf2ZF1prE@shell.armlinux.org.uk>
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From: Choong Yong Liang <yong.liang.choong@linux.intel.com>
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On 1/2/2024 4:38 pm, Russell King (Oracle) wrote:
> Note the "This must not modify any state." statement. By reinitialising
> the PCS in this method, you are violating that statement.
> 
> This requirement is because this method will be called by
> phylink_validate_mac_and_pcs() at various times, potentially for each
> and every interface that stmmac supports, which will lead to you
> reinitialising the PCS, killing the link, each time we ask the MAC for
> a PCS, whether we are going to make use of it in that mode or not.
> 
> You can not do this. Sorry. Hard NAK for this approach.
> 
Thank you for taking the time to review, got your concerns, and I'll 
address the following concerns before submitting a new patch series:

1. Remove allow_switch_interface and have the PHY driver fill in 
phydev->possible_interfaces.
2. Rework on the PCS to have similar implementation with the following 
patch "net: macb: use .mac_select_pcs() interface" 
(https://lore.kernel.org/netdev/E1n568J-002SZX-Gr@rmk-PC.armlinux.org.uk/T/).

Kindly let me know if there are any additional concerns or suggestions.