netdev - Re: [PATCH] net: phy: Move interrupt check from phy_check to phy

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Message-ID: <20180308162905.GE5144@lunn.ch>
Date:   Thu, 8 Mar 2018 17:29:05 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     Brad Mouring <brad.mouring@...com>
Cc:     Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] net: phy: Move interrupt check from phy_check to
 phy_interrupt

On Wed, Mar 07, 2018 at 04:50:42PM -0600, Brad Mouring wrote:
> If multiple phys share the same interrupt (e.g. a multi-phy chip),
> the first device registered is the only one checked as phy_interrupt
> will always return IRQ_HANDLED if the first phydev is not halted.
> Move the interrupt check into phy_interrupt and, if it was not this
> phydev, return IRQ_NONE to allow other devices on this irq a chance
> to check if it was their interrupt.
> 
> Signed-off-by: Brad Mouring <brad.mouring@...com>
> ---
>  drivers/net/phy/phy.c | 16 ++++++----------
>  1 file changed, 6 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index e3e29c2b028b..ff1aa815568f 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -632,6 +632,12 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
>  	if (PHY_HALTED == phydev->state)
>  		return IRQ_NONE;		/* It can't be ours.  */
>  
> +	if (phy_interrupt_is_valid(phydev)) {

Hi Brad

Is this check needed? Can phy_interrupt() be called for a PHY which
does not have an interrupt?

> +		if (phydev->drv->did_interrupt &&
> +			!phydev->drv->did_interrupt(phydev))
> +			return IRQ_NONE;
> +	}
> +
>  	phy_change(phydev);
>  
>  	return IRQ_HANDLED;
> @@ -725,16 +731,6 @@ EXPORT_SYMBOL(phy_stop_interrupts);
>   */
>  void phy_change(struct phy_device *phydev)
>  {
> -	if (phy_interrupt_is_valid(phydev)) {
> -		if (phydev->drv->did_interrupt &&
> -		    !phydev->drv->did_interrupt(phydev))
> -			return;
> -
> -		if (phydev->state == PHY_HALTED)
> -			if (phy_disable_interrupts(phydev))
> -				goto phy_err;
> -	}
> -

phy_change() can also be called via phy_mac_interrupt(). I wonder if
this change is going to break anything? Did you think about that?

Thanks
	Andrew