On Thu, 2019-08-29 at 11:25 +0000, Madalin-cristian Bucur wrote:

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-----Original Message-----
From: Scott Wood <oss@buserror.net>
Sent: Wednesday, August 28, 2019 7:19 AM
To: Valentin Longchamp <redacted>; Madalin-cristian Bucur
[off-list ref]
Cc: linuxppc-dev@lists.ozlabs.org; galak@kernel.crashing.org;
netdev@vger.kernel.org
Subject: Re: [PATCH] powerpc/kmcent2: update the ethernet devices' phy
properties

On Thu, 2019-08-08 at 23:09 +0200, Valentin Longchamp wrote:

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Le mar. 30 juil. 2019 à 11:44, Madalin-cristian Bucur
[off-list ref] a écrit :

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-----Original Message-----

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Le dim. 14 juil. 2019 à 22:05, Valentin Longchamp
[off-list ref] a écrit :

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Change all phy-connection-type properties to phy-mode that are
better
supported by the fman driver.

Use the more readable fixed-link node for the 2 sgmii links.

Change the RGMII link to rgmii-id as the clock delays are added

by

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the
phy.

Signed-off-by: Valentin Longchamp <redacted>

I don't see any other uses of phy-mode in arch/powerpc/boot/dts/fsl,

and

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I see
lots of phy-connection-type with fman.  Madalin, does this patch

look

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OK?

-Scott

Hi,

we are using "phy-connection-type" not "phy-mode" for the NXP (former
Freescale)
DPAA platforms. While the two seem to be interchangeable ("phy-mode"

seems

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to be
more recent, looking at the device tree bindings), the driver code in
Linux seems
to use one or the other, not both so one should stick with the variant

the

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driver
is using. To make things more complex, there may be dependencies in
bootloaders,
I see code in u-boot using only "phy-connection-type" or only "phy-

mode".

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I'd leave "phy-connection-type" as is.

So I have finally had time to have a look and now I understand what
happens. You are right, there are bootloader dependencies: u-boot
calls fdt_fixup_phy_connection() that somehow in our case adds (or
changes if already in the device tree) the phy-connection-type
property to a wrong value ! By having a phy-mode in the device tree,
that is not changed by u-boot and by chance picked up by the kernel
fman driver (of_get_phy_mode() ) over phy-connection-mode, the below
patch fixes it for us.

I agree with you, it's not correct to have both phy-connection-type
and phy-mode. Ideally, u-boot on the board should be reworked so that
it does not perform the above wrong fixup. However, in an "unfixed"
.dtb (I have disabled fdt_fixup_phy_connection), the device tree in
the end only has either phy-connection-type or phy-mode, according to
what was chosen in the .dts file. And the fman driver works well with
both (thanks to the call to of_get_phy_mode() ). I would therefore
argue that even if all other DPAA platforms use phy-connection-type,
phy-mode is valid as well. (Furthermore we already have hundreds of
such boards in the field and we don't really support "remote" u-boot
update, so the u-boot fix is going to be difficult for us to pull).

Valentin

Madalin, are you OK with the patch given this explanation?

-Scott

Yes, I understand that it's the only option they have, given the inability
to upgrade u-boot (this may prove to be an issue in the future, in other
situations).

Acked-by: Madalin Bucur <madalin.bucur@nxp.com>

Acked-by: Scott Wood <oss@buserror.net>

-Scott