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Date:   Wed, 19 Oct 2022 13:49:28 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Clark Wang <xiaoning.wang@nxp.com>
Cc:     peppe.cavallaro@st.com, alexandre.torgue@foss.st.com,
        joabreu@synopsys.com, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, mcoquelin.stm32@gmail.com,
        netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-imx@nxp.com
Subject: Re: [PATCH] net: stmmac: linkup phy after enabled mac when system
 resume
Message-ID: <Y0/yWHvHs6NHdB8W@shell.armlinux.org.uk>
References: <20221019123643.1937889-1-xiaoning.wang@nxp.com>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Wed, Oct 19, 2022 at 08:36:43PM +0800, Clark Wang wrote:
> +	mutex_unlock(&priv->lock);
> +	if (device_may_wakeup(priv->device) && priv->plat->pmt) {
> +		phylink_resume(priv->phylink);
> +	} else {
> +		phylink_resume(priv->phylink);
> +		if (device_may_wakeup(priv->device))
> +			phylink_speed_up(priv->phylink);
> +	}
> +	mutex_lock(&priv->lock);

First, is there a reason this isn't coded as:

	mutex_unlock(&priv->lock);
	phylink_resume(priv->phylink);

	if (!priv->plat->pmt && device_may_wakeup(priv->device))
		phylink_speed_up(priv->phylink);

	mutex_lock(&priv->lock);

And secondly, is it really safe to drop this lock? What specifically
is the lock protecting? I see this isn't documented in the driver...

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