Re: [PATCH v5 3/6] net: phy: at803x: add QCA8084 ethernet phy support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Nov 20, 2023 at 04:34:55PM +0100, Andrew Lunn wrote:
> Are you saying there is a USXGMII-M level link change status? The link
> between the SoC and the PHY package is up/down? If it is down, all
> four MAC-PHY links are down. If it is up, it is possible to carry
> frames between the SoC and the PHY package, but maybe the PHYs
> themselves are down?

It shouldn't do. Each "channel" in the USXGMII-M link has its own
autoneg block at both ends, each conveys link status independently.

The MAC side structure is:


                            +----------+                +-----+
                    .-XGMII-> Rate     |    PCS         |     |
MAC1 <-MDI-> PHY <-+        | Adaption <--> Clause 49 <->     |
                    `-GMII-->          |                |     |
                            +-----^----+                |     |
                                  |                     |     |
                            +-----v---- +               |     |
                            | Autoneg   |               |     |
                            | Clause 37 |               |     |
                            +-----------+               |     |
                                                        | Mux <--> PMA <-->
                                                        |     |
                                                        .......     USXGMII-M

<------------------------------------------------------>
      These blocks are repeated for each channel

The spec goes on to state that there must be a USXGMII enable bit that
defaults to disabled and the PHY should assume normal XGMII/XFI
operation. When enabled, autoneg follows a slight modification of
clause 37-6.

As far as the USXGMII-M link, I believe 2.7.8 in the USXGMII-M
documentation covers this, which is "hardware autoneg programming
sequence". It states that "if 10G link is lost or regained, the
software is expected to disable autoneg and re-enable autoneg". I
think "10G link" refers to the USXGMII-M connection, which means
the loss of that link shold cause software to intervene in each
of the PCS autoneg blocks. It is, however, rather unclear.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux