From: Andrew Lunn <andrew@lunn.ch>
To: Francesco Dolcini <francesco.dolcini@toradex.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
philippe.schenker@toradex.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: micrel: ksz9131 led errata workaround
Date: Wed, 6 Oct 2021 23:57:45 +0200 [thread overview]
Message-ID: <YV4b2QRZu0yL4Ss0@lunn.ch> (raw)
In-Reply-To: <20211006073755.429469-1-francesco.dolcini@toradex.com>
On Wed, Oct 06, 2021 at 09:37:55AM +0200, Francesco Dolcini wrote:
> Micrel KSZ9131 PHY LED behavior is not correct when configured in
> Individual Mode, LED1 (Activity LED) is in the ON state when there is
> no-link.
>
> Workaround this by setting bit 9 of register 0x1e after verifying that
> the LED configuration is Individual Mode.
>
> This issue is described in KSZ9131RNX Silicon Errata DS80000693B
> (http://ww1.microchip.com/downloads/en/DeviceDoc/80000863A.pdf) and
> according to that it will not be corrected in a future silicon revision.
>
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
> drivers/net/phy/micrel.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index c330a5a9f665..661dedec84c4 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -1003,6 +1003,23 @@ static int ksz9131_config_rgmii_delay(struct phy_device *phydev)
> txcdll_val);
> }
>
> +/* Silicon Errata DS80000693B
> + *
> + * When LEDs are configured in Individual Mode, LED1 is ON in a no-link
> + * condition. Workaround is to set register 0x1e, bit 9, this way LED1 behaves
> + * according to the datasheet (off if there is no link).
> + */
> +
> +static int ksz9131_led_errata(struct phy_device *phydev)
> +{
> + int ret = 0;
> +
> + if (phy_read_mmd(phydev, 2, 0) & BIT(4))
It would be good to check the return code here. If there is an error,
you are going to set bit 9.
Otherwise this looks O.K.
Andrew
prev parent reply other threads:[~2021-10-06 21:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-06 7:37 [PATCH] net: phy: micrel: ksz9131 led errata workaround Francesco Dolcini
2021-10-06 9:39 ` Francesco Dolcini
2021-10-06 21:57 ` Andrew Lunn [this message]
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