Re: [PATCH net-next v5 4/5] net: phy: mediatek: Extend 1G TX/RX link pulse time

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: "SkyLake Huang (黃啟澤)" <SkyLake.Huang@mediatek.com>
Cc: "andrew@lunn.ch" <andrew@lunn.ch>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mediatek@lists.infradead.org"
	<linux-mediatek@lists.infradead.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"kuba@kernel.org" <kuba@kernel.org>,
	"pabeni@redhat.com" <pabeni@redhat.com>,
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	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"dqfext@gmail.com" <dqfext@gmail.com>,
	"Steven Liu (劉人豪)" <steven.liu@mediatek.com>,
	"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"hkallweit1@gmail.com" <hkallweit1@gmail.com>,
	"daniel@makrotopia.org" <daniel@makrotopia.org>,
	"angelogioacchino.delregno@collabora.com"
	<angelogioacchino.delregno@collabora.com>
Subject: Re: [PATCH net-next v5 4/5] net: phy: mediatek: Extend 1G TX/RX link pulse time
Date: Thu, 30 May 2024 17:10:21 +0100	[thread overview]
Message-ID: <Zlik7TfUsOanlBMV@shell.armlinux.org.uk> (raw)
In-Reply-To: <a6280b885cf1cffa845310e7e565e1dd7421dc66.camel@mediatek.com>

On Thu, May 30, 2024 at 04:01:08PM +0000, SkyLake Huang (黃啟澤) wrote:
> I'm not going to handle timeout case here. If we can't detect
> MTK_PHY_FINAL_SPEED_1000 in 1 second, let it go and we'll detect it
> next round.

With this waiting up to one second for MTK_PHY_FINAL_SPEED_1000 to be
set...

> > > +int mtk_gphy_cl22_read_status(struct phy_device *phydev)
> > > +{
> > > +int ret;
> > > +
> > > +ret = genphy_read_status(phydev);
> > > +if (ret)
> > > +return ret;
> > > +
> > > +if (phydev->autoneg == AUTONEG_ENABLE && !phydev-
> > >autoneg_complete) {

Are you sure you want this condition like this? When the link is down,
and 1G speeds are being advertised, it means that you'll call
extend_an_new_lp_cnt_limit(). If MTK_PHY_FINAL_SPEED_1000 doesn't get
set, that'll take one second each and every time we poll the PHY for
its status - which will be done while holding phydev->lock.

This doesn't sound very good.

-- 
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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