Re: [PATCH v7 0/8] PCI: Enable Power and configure the TC9563 PCIe switch

Krishna Chaitanya Chundru
2025-10-30T03:43:54Z

On 10/30/2025 4:53 AM, Bjorn Helgaas wrote:
> On Wed, Oct 29, 2025 at 04:59:53PM +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.
>>
>> 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/
> What does this series apply to? It doesn't apply cleanly to v6.18-rc1
> (the normal base for topic branches) or v6.18-rc3 or pci/next.
I sent this on top of rc3 as we have some dependencies with latest
changes i.e ecam changes in dwc driver.
> I tried first applying the patches from
> https://lore.kernel.org/all/20250124101038.3871768-3-krishna.chundru@oss.qualcomm.com/,
> but those don't apply to -rc1 or -rc3 either.

This needs to be applied on the dts schema in github, it is already
applied I will remove this reference in next
series.

- Krishna Chaitanya.

>
> Bjorn