RE: [PATCH net] net: phy: micrel: fix shared interrupt on LAN8814

[Divya.Koppera]

> -----Original Message-----
> From: Michael Walle <michael@xxxxxxxx>
> Sent: Tuesday, September 20, 2022 7:46 PM
> To: Andrew Lunn <andrew@xxxxxxx>; Heiner Kallweit
> <hkallweit1@xxxxxxxxx>; Russell King <linux@xxxxxxxxxxxxxxx>; David S .
> Miller <davem@xxxxxxxxxxxxx>; Eric Dumazet <edumazet@xxxxxxxxxx>;
> Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: Divya Koppera - I30481 <Divya.Koppera@xxxxxxxxxxxxx>;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Horatiu Vultur -
> M31836 <Horatiu.Vultur@xxxxxxxxxxxxx>; Michael Walle
> <michael@xxxxxxxx>
> Subject: [PATCH net] net: phy: micrel: fix shared interrupt on LAN8814
> 
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> Since commit ece19502834d ("net: phy: micrel: 1588 support for LAN8814
> phy") the handler always returns IRQ_HANDLED, except in an error case.
> Before that commit, the interrupt status register was checked and if it was
> empty, IRQ_NONE was returned. Restore that behavior to play nice with the
> interrupt line being shared with others.
> 
> Fixes: ece19502834d ("net: phy: micrel: 1588 support for LAN8814 phy")
> Signed-off-by: Michael Walle <michael@xxxxxxxx>
> ---
>  drivers/net/phy/micrel.c | 18 ++++++++++++------
>  1 file changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index
> 98e9bc101d96..21b6facf6e76 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -2732,16 +2732,19 @@ static int lan8804_config_intr(struct phy_device
> *phydev)  static irqreturn_t lan8814_handle_interrupt(struct phy_device
> *phydev)  {
>         int irq_status, tsu_irq_status;
> +       int ret = IRQ_NONE;
> 
>         irq_status = phy_read(phydev, LAN8814_INTS);
> -       if (irq_status > 0 && (irq_status & LAN8814_INT_LINK))
> -               phy_trigger_machine(phydev);
> -
>         if (irq_status < 0) {
>                 phy_error(phydev);
>                 return IRQ_NONE;
>         }
> 
> +       if (irq_status & LAN8814_INT_LINK) {
> +               phy_trigger_machine(phydev);
> +               ret = IRQ_HANDLED;
> +       }
> +
>         while (1) {
>                 tsu_irq_status = lanphy_read_page_reg(phydev, 4,
>                                                       LAN8814_INTR_STS_REG); @@ -2750,12 +2753,15
> @@ static irqreturn_t lan8814_handle_interrupt(struct phy_device *phydev)
>                     (tsu_irq_status & (LAN8814_INTR_STS_REG_1588_TSU0_ |
>                                        LAN8814_INTR_STS_REG_1588_TSU1_ |
>                                        LAN8814_INTR_STS_REG_1588_TSU2_ |
> -                                      LAN8814_INTR_STS_REG_1588_TSU3_)))
> +
> + LAN8814_INTR_STS_REG_1588_TSU3_))) {
>                         lan8814_handle_ptp_interrupt(phydev);
> -               else
> +                       ret = IRQ_HANDLED;
> +               } else {
>                         break;
> +               }
>         }
> -       return IRQ_HANDLED;
> +
> +       return ret;
>  }
> 
>  static int lan8814_ack_interrupt(struct phy_device *phydev)
> --
> 2.30.2

Reviewed-by: Divya Koppera <Divya.Koppera@xxxxxxxxxxxxx>