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Date:   Thu, 21 Sep 2023 15:12:19 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Choong Yong Liang <yong.liang.choong@linux.intel.com>,
        Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>,
        David E Box <david.e.box@linux.intel.com>,
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        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
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        Jakub Kicinski <kuba@kernel.org>,
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        Marek =?iso-8859-1?Q?Beh=FAn?= <kabel@kernel.org>,
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        Guenter Roeck <linux@roeck-us.net>,
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Subject: Re: [PATCH net-next v2 0/5] TSN auto negotiation between 1G and 2.5G
Message-ID: <ZQxPQ9t8/TKcjlo8@shell.armlinux.org.uk>
References: <20230804084527.2082302-1-yong.liang.choong@linux.intel.com>
 <5bd05ba2-fd88-4e5c-baed-9971ff917484@lunn.ch>
 <f9b21a9d-4ae2-1f91-b621-2e27f746f661@linux.intel.com>
 <37fe9352-ec84-47b8-bb49-9441987ca1b9@lunn.ch>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Thu, Sep 21, 2023 at 03:21:00PM +0200, Andrew Lunn wrote:
> > Hi Andrew,
> > 
> > After conducting a comprehensive study, it seems that implementing
> > out-of-band for all link modes might not be feasible. I may have missed some
> > key aspects during my analysis.
> > 
> > Would you be open to sharing a high-level idea of how we could potentially
> > make this feasible? Your insights would be greatly appreciated.
> 
> stmmac_mac_link_up() gets passed interface, speed and duplex. That
> tells you what the PHY has negotiated. Is there anything else you need
> to know?

The problem is... the stmmac driver is utter bollocks - that information
is *not* passed to the BSP. Instead, stmmac parse and store information
such as the PHY interface mode at initialisation time. BSPs also re-
parse and store e.g. the PHY interface mode at initialisation time.
The driver ignores what it gets from phylink.

The driver is basically utter crap. That's an area I _had_ patches to
clean up. I no longer do. stmmac is crap crap crap and will stay crap
until they become more receptive to patches to fix it, even if the
patches are not 100% to their liking but are in fact correct. Maybe
if I ever decide to touch that driver in the future. Which I doubt
given my recent experience.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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