From: "Ardelean, Alexandru" <alexandru.Ardelean@analog.com>
To: "andrew@lunn.ch" <andrew@lunn.ch>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
"hkallweit1@gmail.com" <hkallweit1@gmail.com>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>
Subject: Re: [PATCH 06/16] net: phy: adin: support PHY mode converters
Date: Wed, 7 Aug 2019 08:00:53 +0000 [thread overview]
Message-ID: <7747cb845a9122004b9565f444b4719170f74b35.camel@analog.com> (raw)
In-Reply-To: <20190806153910.GB20422@lunn.ch>
On Tue, 2019-08-06 at 17:39 +0200, Andrew Lunn wrote:
> [External]
>
> On Tue, Aug 06, 2019 at 06:47:08AM +0000, Ardelean, Alexandru wrote:
> > On Mon, 2019-08-05 at 16:51 +0200, Andrew Lunn wrote:
> > > [External]
> > >
> > > On Mon, Aug 05, 2019 at 07:54:43PM +0300, Alexandru Ardelean wrote:
> > > > Sometimes, the connection between a MAC and PHY is done via a
> > > > mode/interface converter. An example is a GMII-to-RGMII converter, which
> > > > would mean that the MAC operates in GMII mode while the PHY operates in
> > > > RGMII. In this case there is a discrepancy between what the MAC expects &
> > > > what the PHY expects and both need to be configured in their respective
> > > > modes.
> > > >
> > > > Sometimes, this converter is specified via a board/system configuration (in
> > > > the device-tree for example). But, other times it can be left unspecified.
> > > > The use of these converters is common in boards that have FPGA on them.
> > > >
> > > > This patch also adds support for a `adi,phy-mode-internal` property that
> > > > can be used in these (implicit convert) cases. The internal PHY mode will
> > > > be used to specify the correct register settings for the PHY.
> > > >
> > > > `fwnode_handle` is used, since this property may be specified via ACPI as
> > > > well in other setups, but testing has been done in DT context.
> > >
> > > Looking at the patch, you seems to assume phy-mode is what the MAC is
> > > using? That seems rather odd, given the name. It seems like a better
> > > solution would be to add a mac-mode, which the MAC uses to configure
> > > its side of the link. The MAC driver would then implement this
> > > property.
> > >
> >
> > actually, that's a pretty good idea;
> > i guess i was narrow-minded when writing the driver, and got stuck on phy specifics, and forgot about the MAC-side;
> > [ i also catch these design elements when reviewing, but i also seem to miss them when writing stuff sometimes ]
> >
>
> Hi Ardelean
>
> We should also consider the media converter itself. It is passive, or
> does it need a driver. You seems to be considering GMII-to-RGMII. But
> what about RGMII to SGMII? or RGMII to 1000Base-KX etc? Ideally we
> want a generic solution and we need to think about all the parts in
> the system.
In our case the GMII-to-RGMII converter is passive and does not need a driver.
It's an HDL/FPGA block.
There may be other converters that do need a driver.
To be honest, the multitude of possible configurations [given that it's FPGA] can be... a lot.
In one of our cases, specifying the MAC mode to be different than PHY mode [which assumes that there is an implicit
passive media converter in-between] works.
I admit that a generic solution would be nice.
Is it ok if we defer the solution for this drivers/patchset?
If you propose something, I can take a look as part of a different/new discussion.
No guarrantees about how soon it would be implemented.
Thanks
Alex
>
> Andrew
next prev parent reply other threads:[~2019-08-07 8:01 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-05 16:54 [PATCH 00/16] net: phy: adin: add support for Analog Devices PHYs Alexandru Ardelean
2019-08-05 16:54 ` [PATCH 01/16] " Alexandru Ardelean
2019-08-05 14:16 ` Andrew Lunn
2019-08-06 6:32 ` Ardelean, Alexandru
2019-08-05 15:17 ` Andrew Lunn
2019-08-06 6:35 ` Ardelean, Alexandru
2019-08-05 20:54 ` Heiner Kallweit
2019-08-06 6:35 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 02/16] net: phy: adin: hook genphy_{suspend,resume} into the driver Alexandru Ardelean
2019-08-05 14:17 ` Andrew Lunn
2019-08-05 16:54 ` [PATCH 03/16] net: phy: adin: add support for interrupts Alexandru Ardelean
2019-08-05 14:21 ` Andrew Lunn
2019-08-06 6:37 ` Ardelean, Alexandru
2019-08-05 21:02 ` Heiner Kallweit
2019-08-06 6:38 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 04/16] net: phy: adin: add {write,read}_mmd hooks Alexandru Ardelean
2019-08-05 14:25 ` Andrew Lunn
2019-08-06 6:38 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 05/16] net: phy: adin: configure RGMII/RMII/MII modes on config Alexandru Ardelean
2019-08-05 14:39 ` Andrew Lunn
2019-08-06 6:43 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 06/16] net: phy: adin: support PHY mode converters Alexandru Ardelean
2019-08-05 14:51 ` Andrew Lunn
2019-08-06 6:47 ` Ardelean, Alexandru
2019-08-06 15:39 ` Andrew Lunn
2019-08-07 8:00 ` Ardelean, Alexandru [this message]
2019-08-07 13:20 ` Andrew Lunn
2019-08-05 16:54 ` [PATCH 07/16] net: phy: adin: make RGMII internal delays configurable Alexandru Ardelean
2019-08-05 16:54 ` [PATCH 08/16] net: phy: adin: make RMII fifo depth configurable Alexandru Ardelean
2019-08-05 16:54 ` [PATCH 09/16] net: phy: adin: add support MDI/MDIX/Auto-MDI selection Alexandru Ardelean
2019-08-05 16:54 ` [PATCH 10/16] net: phy: adin: add EEE translation layer for Clause 22 Alexandru Ardelean
2019-08-05 22:11 ` Andrew Lunn
2019-08-06 6:47 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 11/16] net: phy: adin: PHY reset mechanisms Alexandru Ardelean
2019-08-05 15:15 ` Andrew Lunn
2019-08-06 6:50 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 12/16] net: phy: adin: read EEE setting from device-tree Alexandru Ardelean
2019-08-05 15:19 ` Andrew Lunn
2019-08-06 6:52 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 13/16] net: phy: adin: implement Energy Detect Powerdown mode Alexandru Ardelean
2019-08-05 16:54 ` [PATCH 14/16] net: phy: adin: make sure down-speed auto-neg is enabled Alexandru Ardelean
2019-08-05 15:22 ` Andrew Lunn
2019-08-06 6:53 ` Ardelean, Alexandru
2019-08-06 5:52 ` Heiner Kallweit
2019-08-06 6:53 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 15/16] net: phy: adin: add ethtool get_stats support Alexandru Ardelean
2019-08-05 15:28 ` Andrew Lunn
2019-08-06 7:11 ` Ardelean, Alexandru
2019-08-06 15:46 ` Andrew Lunn
2019-08-07 7:52 ` Ardelean, Alexandru
2019-08-05 15:30 ` Andrew Lunn
2019-08-06 7:18 ` Ardelean, Alexandru
2019-08-05 16:54 ` [PATCH 16/16] dt-bindings: net: add bindings for ADIN PHY driver Alexandru Ardelean
2019-08-05 14:11 ` Andrew Lunn
2019-08-06 7:03 ` Ardelean, Alexandru
2019-08-06 11:47 ` Ardelean, Alexandru
2019-08-05 14:27 ` Andrew Lunn
2019-08-06 6:57 ` Ardelean, Alexandru
2019-08-06 15:04 ` Rob Herring
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