RE: [PATCH v4 net-next 2/2] net: phy: micrel: Fix warn: passing zero to PTR_ERR

[Divya.Koppera]

Hi Andrew,

> -----Original Message-----
> From: Andrew Lunn <andrew@xxxxxxx>
> Sent: Monday, December 5, 2022 7:12 PM
> To: Divya Koppera - I30481 <Divya.Koppera@xxxxxxxxxxxxx>
> Cc: hkallweit1@xxxxxxxxx; linux@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx;
> edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> richardcochran@xxxxxxxxx; UNGLinuxDriver
> <UNGLinuxDriver@xxxxxxxxxxxxx>; Madhuri Sripada - I34878
> <Madhuri.Sripada@xxxxxxxxxxxxx>
> Subject: Re: [PATCH v4 net-next 2/2] net: phy: micrel: Fix warn: passing zero
> to PTR_ERR
> 
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> 
> On Mon, Dec 05, 2022 at 04:05:50PM +0530, Divya Koppera wrote:
> > Handle the NULL pointer case
> >
> > Fixes New smatch warnings:
> > drivers/net/phy/micrel.c:2613 lan8814_ptp_probe_once() warn: passing
> zero to 'PTR_ERR'
> >
> > vim +/PTR_ERR +2613 drivers/net/phy/micrel.c
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Fixes: ece19502834d ("net: phy: micrel: 1588 support for LAN8814 phy")
> > Signed-off-by: Divya Koppera <Divya.Koppera@xxxxxxxxxxxxx>
> > ---
> > v3 -> v4:
> > - Split the patch for different warnings
> > - Renamed variable from shared_priv to shared.
> >
> > v2 -> v3:
> > - Changed subject line from net to net-next
> > - Removed config check for ptp and clock configuration
> >   instead added null check for ptp_clock
> > - Fixed one more warning related to initialisaton.
> >
> > v1 -> v2:
> > - Handled NULL pointer case
> > - Changed subject line with net-next to net
> > ---
> >  drivers/net/phy/micrel.c | 15 ++++++++-------
> >  1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index
> > 1bcdb828db56..0399f3830700 100644
> > --- a/drivers/net/phy/micrel.c
> > +++ b/drivers/net/phy/micrel.c
> > @@ -2971,12 +2971,13 @@ static int lan8814_config_intr(struct
> > phy_device *phydev)
> >
> >  static void lan8814_ptp_init(struct phy_device *phydev)  {
> > +     struct lan8814_shared_priv *shared = phydev->shared->priv;
> >       struct kszphy_priv *priv = phydev->priv;
> >       struct kszphy_ptp_priv *ptp_priv = &priv->ptp_priv;
> >       u32 temp;
> >
> > -     if (!IS_ENABLED(CONFIG_PTP_1588_CLOCK) ||
> > -         !IS_ENABLED(CONFIG_NETWORK_PHY_TIMESTAMPING))
> > +     /* Check if PHC support is missing at the configuration level */
> > +     if (!shared->ptp_clock)
> >               return;
> 
> Can you somehow keep the IS_ENABLED() ? It gets evaluated at compile time.
> The optimizer can see the function will always return here, and all the code
> that follows is pointless, and so remove it. By turning this into a runtime test,
> you have made the image bigger.
> 

Thanks, will change this.

>      Andrew
/Divya