On 03/08/2024 05:22, Krishna chaitanya chundru wrote: > QPS615 is the PCIe switch which has one upstream and three downstream > ports. One of the downstream ports is used as endpoint device of Ethernet > MAC. Other two downstream ports are supposed to connect to external > device. One Host can connect to QPS615 by upstream port. > > QPS615 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 QPS615 needs to configured certain parameters like de-emphasis, > disable unused port etc before link is established. > > The device tree properties are parsed per node under pci-pci bridge in the > devicetree. Each node has unique bdf value in the reg property, driver > uses this bdf to differentiate ports, as there are certain i2c writes to > select particulat port. > > As the controller starts link training before the probe of pwrctl driver, > the PCIe link may come up before configuring the switch itself. > 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. > > Now PCI pwrctl device is the child of the pci-pcie bridge, if we want > to enable the suspend resume for pwrctl device there may be issues > since pci bridge will try to access some registers in the config which > may cause timeouts or Un clocked access as the power can be removed in > the suspend of pwrctl driver. > > To solve this make PCIe controller as parent to the pci pwr ctrl driver > and create devlink between host bridge and pci pwrctl driver so that > pci pwrctl driver will go suspend only after all the PCIe devices went > to suspend. > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> > --- > Changes in V1: > - Fix the code as per the comments given. You did not implement the comments so such changelog is rather a joke. Respond to each comment from v1 and acknowledge it. Then write detailed changelog. Best regards, Krzysztof
