linux-kernel - Re: [PATCH net] net: micrel: Fix lan8841_config

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Message-ID: <f73778fe-ef01-44b4-9a8d-cd2a978c1a3d@lunn.ch>
Date: Thu, 23 May 2024 16:32:26 +0200
From: Andrew Lunn <andrew@...n.ch>
To: Horatiu Vultur <horatiu.vultur@...rochip.com>
Cc: hkallweit1@...il.com, linux@...linux.org.uk, davem@...emloft.net,
	edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net] net: micrel: Fix lan8841_config_intr after getting
 out of sleep mode

On Thu, May 23, 2024 at 09:42:26AM +0200, Horatiu Vultur wrote:
> When the interrupt is enabled, the function lan8841_config_intr tries to
> clear any pending interrupts by reading the interrupt status, then
> checks the return value for errors and then continue to enable the
> interrupt. It has been seen that once the system gets out of sleep mode,
> the interrupt status has the value 0x400 meaning that the PHY detected
> that the link was in low power. That is correct value but the problem is
> that the check is wrong.  We try to check for errors but we return an
> error also in this case which is not an error. Therefore fix this by
> returning only when there is an error.

Is the second case also broken in the same way?

	} else {
		err = phy_write(phydev, LAN8814_INTC, 0);
		if (err)
			return err;

		err = phy_read(phydev, LAN8814_INTS);
	}

	return err;

e.g. there was an outstanding interrupt as interrupts are
disabled. This will cause the return value of the function to be not
0?

	Andrew