Re: [PATCH net-next 4/6] net: stmmac: rk: use stmmac_set_tx_clk_gmii()

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Serge Semin <fancer.lancer@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	Alexei Starovoitov <ast@kernel.org>,
	bpf@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>,
	"David S. Miller" <davem@davemloft.net>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Eric Dumazet <edumazet@google.com>,
	Fabio Estevam <festevam@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-stm32@st-md-mailman.stormreply.com,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	netdev@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Samin Guo <samin.guo@starfivetech.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Shawn Guo <shawnguo@kernel.org>
Subject: Re: [PATCH net-next 4/6] net: stmmac: rk: use stmmac_set_tx_clk_gmii()
Date: Thu, 14 Sep 2023 16:03:17 +0100	[thread overview]
Message-ID: <ZQMgtXSTsNoZohnx@shell.armlinux.org.uk> (raw)
In-Reply-To: <7vhtvd25qswsju34lgqi4em5v3utsxlvi3lltyt5yqqecddpyh@c5yvk7t5k5zz>

On Thu, Sep 14, 2023 at 05:37:13PM +0300, Serge Semin wrote:
> On Thu, Sep 14, 2023 at 02:51:35PM +0100, Russell King (Oracle) wrote:
> > Use stmmac_set_tx_clk_gmii().
> > 
> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> > ---
> >  .../net/ethernet/stmicro/stmmac/dwmac-rk.c    | 60 +++++--------------
> >  1 file changed, 16 insertions(+), 44 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> > index d920a50dd16c..5731a73466eb 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> > @@ -1081,28 +1081,14 @@ static void rk3568_set_gmac_speed(struct rk_priv_data *bsp_priv, int speed)
> >  {
> >  	struct clk *clk_mac_speed = bsp_priv->clks[RK_CLK_MAC_SPEED].clk;
> >  	struct device *dev = &bsp_priv->pdev->dev;
> > -	unsigned long rate;
> > -	int ret;
> > -
> > -	switch (speed) {
> > -	case 10:
> > -		rate = 2500000;
> > -		break;
> > -	case 100:
> > -		rate = 25000000;
> > -		break;
> > -	case 1000:
> > -		rate = 125000000;
> > -		break;
> > -	default:
> > -		dev_err(dev, "unknown speed value for GMAC speed=%d", speed);
> > -		return;
> > -	}
> > -
> > -	ret = clk_set_rate(clk_mac_speed, rate);
> > -	if (ret)
> > -		dev_err(dev, "%s: set clk_mac_speed rate %ld failed %d\n",
> > -			__func__, rate, ret);
> > +	int err;
> > +
> > +	err = stmmac_set_tx_clk_gmii(clk_mac_speed, speed);
> > +	if (err == -ENOTSUPP)
> 
> > +		dev_err(dev, "invalid speed %uMbps\n", speed);
> > +	else if (err)
> > +		dev_err(dev, "failed to set tx rate for speed %uMbps: %pe\n",
> 
> These type specifiers should have been '%d' since the speed variable
> is of the signed integer type here.

Okay, having re-reviewed the changes, I'm changing them _all_ back to
be %d, because that is the _right_ thing. It is *not* unsigned, even
if fix_mac_speed() thinks that it is. It isn't. It's signed, and it's
stmmac bollocks implicitly casting it to unsigned - and that is
_wrong_.

So, on that point, my original submission was more correct than this
one, and you led me astray.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

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