Re: [PATCH v4 00/10] PCI: Enable Power and configure the TC956x PCIe switch

Manivannan Sadhasivam
2025-02-27T03:57:47Z

On Tue, Feb 25, 2025 at 03:03:57PM +0530, Krishna Chaitanya Chundru wrote:
> TC956x 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.
>
> TC956x 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 TC956x 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.
>
> Enable global IRQ for PCIe controller so that recan can happen when
> link was up through global IRQ.
>

Move these patches to a separate series.

> This series depends on the https://lore.kernel.org/all/20250124101038.3871768-3-krishna.chundru@oss.qualcomm.com/
>
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> ---
> changes in v3:
> - The QPS615 PCIe switch is rebranded version of Toshiba switch TC956x.
> There is no difference between both the switches, both
> has two open downstream ports and one embedded downstream port
> to which Ethernet MAC is connected.
> As QPS615 is the rebranded version of Toshiba switch rename qps615
> with tc956x so that this driver can be leveraged by all who are using Toshiba switch.

This should be moved to the description as a NOTE.

- Mani

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