Re: [PATCH v7 0/8] PCI: Enable Power and configure the TC9563 PCIe switch
From: Krishna Chaitanya Chundru
Date: Wed Oct 29 2025 - 23:43:42 EST
On 10/30/2025 4:53 AM, Bjorn Helgaas wrote:
On Wed, Oct 29, 2025 at 04:59:53PM +0530, Krishna Chaitanya Chundru wrote:I sent this on top of rc3 as we have some dependencies with latest changes i.e ecam changes in dwc driver.
TC9563 is the PCIe switch which has one upstream and three downstreamWhat does this series apply to? It doesn't apply cleanly to v6.18-rc1
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@xxxxxxxxxxxxxxxx/
(the normal base for topic branches) or v6.18-rc3 or pci/next.
I tried first applying the patches from
https://lore.kernel.org/all/20250124101038.3871768-3-krishna.chundru@xxxxxxxxxxxxxxxx/,
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