netdev - Re: [PATCH net] net: phy: ti: take into account all possible interrupt sources

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Date:   Mon, 1 Mar 2021 10:21:14 +0200
From:   Ioana Ciornei <ciorneiioana@...il.com>
To:     Jakub Kicinski <kuba@...nel.org>
Cc:     Ioana Ciornei <ciorneiioana@...il.com>, davem@...emloft.net,
        netdev@...r.kernel.org, andrew@...n.ch, hkallweit1@...il.com,
        linux@...linux.org.uk, Ioana Ciornei <ioana.ciornei@....com>,
        Sven Schuchmann <schuchmann@...leissheimer.de>
Subject: Re: [PATCH net] net: phy: ti: take into account all possible
 interrupt sources

On Sun, Feb 28, 2021 at 12:00:27PM -0800, Jakub Kicinski wrote:
> On Fri, 26 Feb 2021 17:30:20 +0200 Ioana Ciornei wrote:
> > diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
> > index be1224b4447b..f7a2ec150e54 100644
> > --- a/drivers/net/phy/dp83822.c
> > +++ b/drivers/net/phy/dp83822.c
> > @@ -290,6 +290,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
> >  
> >  static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
> >  {
> > +	bool trigger_machine = false;
> >  	int irq_status;
> >  
> >  	/* The MISR1 and MISR2 registers are holding the interrupt status in
> > @@ -305,7 +306,7 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
> >  		return IRQ_NONE;
> >  	}
> >  	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
> > -		goto trigger_machine;
> > +		trigger_machine = true;
> >  
> >  	irq_status = phy_read(phydev, MII_DP83822_MISR2);
> >  	if (irq_status < 0) {
> > @@ -313,11 +314,11 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
> >  		return IRQ_NONE;
> >  	}
> >  	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
> > -		goto trigger_machine;
> > +		trigger_machine = true;
> >  
> > -	return IRQ_NONE;
> > +	if (!trigger_machine)
> > +		return IRQ_NONE;
> >  
> > -trigger_machine:
> >  	phy_trigger_machine(phydev);
> >  
> >  	return IRQ_HANDLED;
> 
> Would it be better to code it up as:
> 
> 	irqreturn_t ret = IRQ_NONE;
> 
> 	if (irq_status & ...)
> 		ret = IRQ_HANDLED;
> 
> 	/* .. */
> 
> 	if (ret != IRQ_NONE)
> 		phy_trigger_machine(phydev);
> 
> 	return ret;
> 
> That reads a tiny bit better to me, but it's probably majorly
> subjective so I'm happy with existing patch if you prefer it.

I think I prefer it as it is and this is because it would be in line
with all the other PHY drivers which do this:

	if (!(irq_status & int_enabled))
		return IRQ_NONE;

	phy_trigger_machine(phydev);

	return IRQ_HANDLED;

Ioana