On Thu, Mar 5, 2026 at 6:13 AM Jim MacArthur <[email protected]>
wrote:

> There are other registers in the PHY model which should be partially or
> entirely read-only, but this solves the immediate issue.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3297
>
> Signed-off-by: Jim MacArthur <[email protected]>
>

Reviewed-by: Edgar E. Iglesias <[email protected]>




> ---
> See:
>
> https://gitlab.com/qemu-project/qemu/-/issues/3297
>
>
> https://lore.kernel.org/qemu-devel/CAJy5ezqTAMr=a3uafmuwlepk66adlru4q8amfmh4+4q2htd...@mail.gmail.com/
>
> IEEE 802.3-2022 does not explicitly state that these registers
> should be read-only, but suggests it in 22.2.4.3.1 which says this
> information should be entirely manufacturer-supplied information.
>
> The standard does mention several other registers in the set which
> should be partially or entirely read-only, so further work may be
> required.
> ---
>  hw/net/xilinx_axienet.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/hw/net/xilinx_axienet.c b/hw/net/xilinx_axienet.c
> index d85f8bb23f..970732b162 100644
> --- a/hw/net/xilinx_axienet.c
> +++ b/hw/net/xilinx_axienet.c
> @@ -141,6 +141,10 @@ tdk_write(struct PHY *phy, unsigned int req, unsigned
> int data)
>      regnum = req & 0x1f;
>      DPHY(qemu_log("%s reg[%d] = %x\n", __func__, regnum, data));
>      switch (regnum) {
> +        case 2:
> +        case 3:
> +            /* Writes to PHY Identification registers are disallowed */
> +            break;
>          default:
>              phy->regs[regnum] = data;
>              break;
>
> ---
> base-commit: 3fb456e9a0e9eef6a71d9b49bfff596a0f0046e9
> change-id: 20260305-xilinx-phy-protection-c396a658d072
>
> Best regards,
> --
> Jim MacArthur <[email protected]>
>
>

Reply via email to