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Date: Fri, 19 Jan 2024 04:05:29 +0100 (CET)
From: Andre Werner <andre.werner@systec-electronic.com>
Reply-To: Andre Werner <andre.werner@systec-electronic.com>
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
cc: Andre Werner <andre.werner@systec-electronic.com>, andrew@lunn.ch, 
    hkallweit1@gmail.com, davem@davemloft.net, edumazet@google.com, 
    kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, 
    linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: adin1100: Fix nullptr exception for phy
 interrupts
In-Reply-To: <Zald7u8B+uKzCn42@shell.armlinux.org.uk>
Message-ID: <48245ebe-babf-52ec-407b-9ce32ffe24d2@systec-electronic.com>
References: <20240118104341.10832-1-andre.werner@systec-electronic.com> <Zald7u8B+uKzCn42@shell.armlinux.org.uk>
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On Thu, 18 Jan 2024, Russell King (Oracle) wrote:

> In addition to Andrew's comments:
>
> On Thu, Jan 18, 2024 at 11:43:41AM +0100, Andre Werner wrote:
>> +static int adin_config_intr(struct phy_device *phydev)
>> +{
>> +	int ret, regval;
>> +
>> +	ret = adin_phy_ack_intr(phydev);
>> +
>> +	if (ret)
>> +		return ret;
>> +
>> +	regval = phy_read_mmd(phydev, MDIO_MMD_VEND2, ADIN_PHY_SUBSYS_IRQ_MASK);
>> +	if (regval < 0)
>> +		return regval;
>> +
>> +	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
>> +		regval |= ADIN_LINK_STAT_CHNG_IRQ_EN;
>> +	else
>> +		regval &= ~ADIN_LINK_STAT_CHNG_IRQ_EN;
>> +
>> +	ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
>> +			    ADIN_PHY_SUBSYS_IRQ_MASK,
>> +			    regval);
>> +	return ret;
>
> 	u16 irq_mask;
>
> 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
> 		irq_mask = ADIN_LINK_STAT_CHNG_IRQ_EN;
> 	else
> 		irq_mask = 0;

Unfortunately, I can not do this, because that phy ask for read-modify-write access to
registers and some bits in this register are already set after reset and
should not being modified.

>
> 	return phy_modify_mmd(phydev, MDIO_MMD_VEND2,
> 			      ADIN_PHY_SUBSYS_IRQ_MASK,
> 			      ADIN_LINK_STAT_CHNG_IRQ_EN, irq_mask);
>
>> +}
>> +
>> +static irqreturn_t adin_phy_handle_interrupt(struct phy_device *phydev)
>> +{
>> +	int irq_status;
>> +
>> +	irq_status = phy_read_mmd(phydev, MDIO_MMD_VEND2, ADIN_PHY_SUBSYS_IRQ_STATUS);
>
> Probably want to wrap this - if you're going to bother wrapping your
> phy_write_mmd() above because it overflows 80 columns, then please do
> so consistently.

Done.

>
> Thanks.
>
> -- 
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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>