Re: [PATCH 01/20] net: phy: realtek: Fix events detection failure in LPI mode

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Andrew Lunn <andrew@lunn.ch>
Cc: Serge Semin <fancer.lancer@gmail.com>,
	Jose Abreu <Jose.Abreu@synopsys.com>,
	Joao Pinto <Joao.Pinto@synopsys.com>,
	<linux-kernel@vger.kernel.org>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	<netdev@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Jose Abreu <joabreu@synopsys.com>,
	Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Vyacheslav Mitrofanov 
	<Vyacheslav.Mitrofanov@baikalelectronics.ru>,
	"David S. Miller" <davem@davemloft.net>,
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 01/20] net: phy: realtek: Fix events detection failure in LPI mode
Date: Sat, 20 Feb 2021 12:02:48 +0300	[thread overview]
Message-ID: <20210220090248.oiyonlfucvmgzw6d@mobilestation> (raw)
In-Reply-To: <20210211103941.GW1463@shell.armlinux.org.uk>

On Thu, Feb 11, 2021 at 10:39:41AM +0000, Russell King - ARM Linux admin wrote:
> On Wed, Feb 10, 2021 at 07:47:20PM +0300, Serge Semin wrote:
> > On Tue, Feb 09, 2021 at 10:56:46AM +0000, Russell King - ARM Linux admin wrote:
> > > On Tue, Feb 09, 2021 at 11:37:29AM +0100, Heiner Kallweit wrote:
> > > > Right, adding something like a genphy_{read,write}_mmd() doesn't make
> > > > too much sense for now. What I meant is just exporting mmd_phy_indirect().
> > > > Then you don't have to open-code the first three steps of a mmd read/write.
> > > > And it requires no additional code in phylib.
> > > 
> > > ... but at the cost that the compiler can no longer inline that code,
> > > as I mentioned in my previous reply. (However, the cost of the accesses
> > > will be higher.) On the plus side, less I-cache footprint, and smaller
> > > kernel code.
> > 
> > Just to note mmd_phy_indirect() isn't defined with inline specifier,
> > but just as static and it's used twice in the
> > drivers/net/phy/phy-core.c unit. So most likely the compiler won't
> > inline the function code in there.
> 
> You can't always tell whether the compiler will inline a static function
> or not.

Andrew, Heiner, Russell, what is your final decision about this? Shall
we export the mmd_phy_indirect() method, implement new
genphy_{read,write}_mmd() or just leave the patch as is manually
accessing the MMD register in the driver?

-Sergey

> 
> > Anyway it's up to the PHY
> > library maintainers to decide. Please settle the issue with Heiner and
> > Andrew then. I am ok with both solutions and will do as you decide.
> 
> FYI, *I* am one of the phylib maintainers.
> 
> -- 
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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