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Date:   Wed, 26 Jan 2022 15:02:46 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     Tobias Waldekranz <tobias@waldekranz.com>
Cc:     davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
        Marcin Wojtas <mw@semihalf.com>,
        Calvin Johnson <calvin.johnson@oss.nxp.com>,
        Markus Koch <markus@notsyncing.net>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 4/5] net/fsl: xgmac_mdio: Support setting the
 MDC frequency
Message-ID: <YfFUhn+T2SYCaTHc@lunn.ch>
References: <20220126101432.822818-1-tobias@waldekranz.com>
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 <YfFHmkFXtlVus9IW@lunn.ch>
 <87r18ubp57.fsf@waldekranz.com>
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> >> +	if (device_property_read_u32(dev, "clock-frequency", &priv->mdc_freq))
> >> +		return;
> >> +
> >> +	priv->enet_clk = devm_clk_get(dev, NULL);
> >> +	if (IS_ERR(priv->enet_clk)) {
> >> +		dev_err(dev, "Input clock unknown, not changing MDC frequency");
> >
> > Is the clock optional or mandatory?
> 
> As the code is now, it is mandatory. I could add some default frequency,
> but I fear that could do more harm than good?

As i said in the reply to the DT patch, it is mandatory if the
"clock-frequency" parameter is present.

> Ok, no worries about regressions for deployed stuff already out there?

It would only cause a regression if a DT blob happened to have a
'clock-frequency' parameter and not clock, which it should not.

        Andrew