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Date:   Wed, 1 Nov 2023 23:06:56 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     Marco von Rosenberg <marcovr@selfnet.de>
Cc:     Florian Fainelli <florian.fainelli@broadcom.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@broadcom.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: broadcom: Wire suspend/resume for BCM54612E
Message-ID: <fe3ad92f-31d9-4509-b851-017218229e19@lunn.ch>
References: <20231030225446.17422-1-marcovr@selfnet.de>
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On Wed, Nov 01, 2023 at 10:42:52PM +0100, Marco von Rosenberg wrote:
> On Tuesday, October 31, 2023 1:31:11 AM CET Andrew Lunn wrote:
> > Are we talking about a device which as been suspended? The PHY has
> > been left running because there is no suspend callback? Something then
> > triggers a resume. The bootloader then suspends the active PHY? Linux
> > then boots, detects its a resume, so does not touch the hardware
> > because there is no resume callback? The suspended PHY is then
> > useless.
> 
> Hi Andrew,
> 
> thanks for your feedback. I guess a bit of context is missing here. The issue 
> has nothing to do with an ordinary suspension of the OS. The main point is 
> that on initial power-up, the bootloader suspends the PHY before booting 
> Linux. With a resume callback defined, Linux would call it on boot and make the 
> PHY usable.

Ah, so you rely on phy_attach_direct() calling phy_resume(phydev).

This seems an odd way to solve the problem. It was not Linux which
suspend the PHY, so using resume is asymmetric.

I think soft_reset() or config_init() should be taking the PHY out of
suspend.

	Andrew