Re: [PATCH v5 0/9] PCI: Enable Power and configure the TC9563 PCIe switch

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Apr 12, 2025 at 07:19:49AM +0530, Krishna Chaitanya Chundru wrote:
> TC9563 is the PCIe switch which has one upstream and three downstream
> ports. To one of the downstream ports ethernet MAC is connected as endpoint
> device. Other two downstream ports are supposed to connect to external
> device. One Host can connect to TC956x by upstream port.

I guess this topology is for one specific platform that includes the
TC9563?  Since it's a PCIe switch, I assume it could also be used in
other platforms with other topologies?

> TC9563 switch power is controlled by the GPIO's. After powering on
> the switch will immediately participate in the link training. if the
> host is also ready by that time PCIe link will established. 
> 
> The TC9563 needs to configured certain parameters like de-emphasis,
> disable unused port etc before link is established.
> 
> As the controller starts link training before the probe of pwrctl driver,
> the PCIe link may come up as soon as we power on the switch. Due to this
> configuring the switch itself through i2c will not have any effect as
> this configuration needs to done before link training. To avoid this
> introduce two functions in pci_ops to start_link() & stop_link() which
> will disable the link training if the PCIe link is not up yet.
> 
> This series depends on the https://lore.kernel.org/all/20250124101038.3871768-3-krishna.chundru@oss.qualcomm.com/

How so?
https://lore.kernel.org/all/20250124101038.3871768-3-krishna.chundru@oss.qualcomm.com/
adds a schema "n-fts" property, but this series doesn't mention
"n-fts".  This series *does* add this:

  of_property_read_u8_array(node, "nfts", cfg->nfts, 2);

Is that supposed to be the same thing, or does "nfts" magically match
"n-fts"?

Bjorn