netdev - Re: [PATCH v1] net: phy: micrel: Add specific suspend

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Date:	Wed, 3 Aug 2016 20:33:08 -0700
From:	Florian Fainelli <f.fainelli@...il.com>
To:	Wenyou Yang <wenyou.yang@...el.com>
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
	Nicolas Ferre <nicolas.ferre@...el.com>,
	Andrew Lunn <andrew@...n.ch>
Subject: Re: [PATCH v1] net: phy: micrel: Add specific suspend

On 03/08/2016 17:21, Wenyou Yang wrote:
> Disable all interrupts when suspend, they will be enabled
> when resume. Otherwise, the suspend/resume process will be
> blocked occasionally.

This seems like something fairly generic actually, we could imagine
having the core library do something like this:

- if interrupts are valid and enabled for the PHY, call
phydrv->config_intr() with PHY_INTERRUPT_DISABLED
- call genphy_suspend

Of course if none of this fits the generic model, the PHY driver can
still provide a suspend callback. Might be worth auditing other drivers
for that pattern and look at those that need specific handling like
keeping specific interrupt sources active for e.g: wake-on-LAN.

> 
> Signed-off-by: Wenyou Yang <wenyou.yang@...el.com>
> Acked-by: Nicolas Ferre <nicolas.ferre@...el.com>
> ---
> 
>  drivers/net/phy/micrel.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 5a8fefc..8cb778a 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -647,6 +647,23 @@ static void kszphy_get_stats(struct phy_device *phydev,
>  		data[i] = kszphy_get_stat(phydev, i);
>  }
>  
> +int kszphy_suspend(struct phy_device *phydev)
> +{
> +	int value;
> +
> +	mutex_lock(&phydev->lock);
> +
> +	/* disable interrupts */
> +	phy_write(phydev, MII_KSZPHY_INTCS, 0x0);
> +
> +	value = phy_read(phydev, MII_BMCR);
> +	phy_write(phydev, MII_BMCR, value | BMCR_PDOWN);
> +
> +	mutex_unlock(&phydev->lock);
> +
> +	return 0;
> +}
> +
>  static int kszphy_resume(struct phy_device *phydev)
>  {
>  	int value;
> @@ -870,7 +887,7 @@ static struct phy_driver ksphy_driver[] = {
>  	.get_sset_count = kszphy_get_sset_count,
>  	.get_strings	= kszphy_get_strings,
>  	.get_stats	= kszphy_get_stats,
> -	.suspend	= genphy_suspend,
> +	.suspend	= kszphy_suspend,
>  	.resume		= kszphy_resume,
>  }, {
>  	.phy_id		= PHY_ID_KSZ8061,
>