Message-ID: <20250627155837.GC3234475-robh@kernel.org>
Date: Fri, 27 Jun 2025 10:58:37 -0500
From: Rob Herring <robh@...nel.org>
To: Herve Codina <herve.codina@...tlin.com>
Cc: Andrew Lunn <andrew@...n.ch>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
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	Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH v3 00/28] lan966x pci device: Add support for SFPs

On Fri, Jun 13, 2025 at 03:47:40PM +0200, Herve Codina wrote:
> Hi,
> 
> This series add support for SFPs ports available on the LAN966x PCI
> device. In order to have the SFPs supported, additional devices are
> needed such as clock controller and I2C.
> 
> As a reminder, the LAN966x PCI device driver use a device-tree overlay
> to describe devices available on the PCI board. Adding support for SFPs
> ports consists in adding more devices in the already existing
> device-tree overlay.
> 
> With those devices added, the device-tree overlay is more complex and
> some consumer/supplier relationship are needed in order to remove
> devices in correct order when the LAN966x PCI driver is removed.
> 
> Those links are typically provided by fw_devlink and we faced some
> issues with fw_devlink and overlays.
> 
> This series gives the big picture related to the SFPs support from
> fixing issues to adding new devices. Of course, it can be split if
> needed.
> 
> The first part of the series (patch 1, 2 and 3) fixes fw_devlink when it
> is used with overlay. Patches 1 and 3 were previously sent by Saravana
> [0]. I just rebased them on top of v6.15-rc1 and added patch 2 in order
> to take into account feedback received on the series sent by Saravana.
> 
> Those modification were not sufficient in our case and so, on top of
> that, patch 4 and 5 fix some more issues related to fw_devlink.
> 
> Patches 6 to 12 introduce and use fw_devlink_set_device() in already
> existing code.
> 
> Patches 13 and 14 are related also to fw_devlink but specific to PCI and
> the device-tree nodes created during enumeration.
> 
> Patches 15, 15 and 17 are related fw_devlink too but specific to I2C
> muxes. Patches purpose is to correctly set a link between an adapter
> supplier and its consumer. Indeed, an i2c mux adapter's parent is not
> the i2c mux supplier but the adapter the i2c mux is connected to. Adding
> a new link between the adapter supplier involved when i2c muxes are used
> avoid a freeze observed during device removal.
> 
> Patch 18 adds support for fw_delink on x86. fw_devlink is needed to have
> the consumer/supplier relationship between devices in order to ensure a
> correct device removal order. Adding fw_devlink support for x86 has been
> tried in the past but was reverted [1] because it broke some systems.
> Instead of enabling fw_devlink on *all* x86 system or on *all* x86
> system except on those where it leads to issue, enable it only on system
> where it is needed.
> 
> Patches 19 and 20 allow to build clock and i2c controller used by the
> LAN966x PCI device when the LAN966x PCI device is enabled.
> 
> Patches 21 to 25 are specific to the LAN966x. They touch the current
> dtso, split it in dtsi/dtso files, rename the dtso and improve the
> driver to allow easier support for other boards.
> 
> The next patch (patch 26) update the LAN966x device-tree overlay itself
> to have the SPF ports and devices they depends on described.
> 
> The last two patches (patches 27 and 28) sort the existing drivers in
> the needed driver list available in the Kconfig help and add new drivers
> in this list keep the list up to date with the devices described in the
> device-tree overlay.
> 
> Once again, this series gives the big picture and can be split if
> needed. Let me know.

Please suggest how you think this should get merged? There's 8 
maintainer trees involved here. Some parts can be merged independently? 
We need to spread over 2 cycles? Greg just takes it all?

Rob

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