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

From: Serge Semin
Date: Sat Feb 20 2021 - 04:05:52 EST


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.
>
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