Re: [PATCH 0/5] net: ftgmac100: Add AST2700 support

From: Andrew Lunn

Date: Sun Sep 27 2026 - 13:40:12 EST


On Sun, Sep 27, 2026 at 03:16:19PM +0800, Jacky Chou wrote:
> Add the pieces needed for the FTGMAC100 driver to run on Aspeed AST2700
> systems.
>
> AST2700 keeps using the FTGMAC100 MAC IP, but the enablement is not
> limited to a new compatible string. The SoC can boot with the MAC on
> ARM64, needs the Aspeed-specific RMII mode bit programmed when a port is
> wired for RMII, and requires the driver to use the upper DMA address
> fields in the ring base registers and packet descriptors. Those fields
> expose a 35-bit DMA address range on AST2700, so the driver must request
> a mask that matches the address bits the hardware can encode.
>
> The series first documents and wires up the aspeed,ast2700-mac
> compatible. It then treats AST2700 as an Aspeed MAC in the driver,
> enables the RMII mode programming, writes the AST2700 high descriptor-ring
> base registers, carries the RX/TX descriptor high address bits, rebuilds
> full DMA addresses before unmapping buffers, and requests a 35-bit DMA
> mask. The high ring base registers are only touched for AST2700 so older
> Aspeed device tree register windows remain unchanged. With that in place,
> the FTGMAC100 Kconfig entry can be made available on ARM64 while keeping
> the existing Aspeed MDIO dependency for AST2600 and newer ARCH_ASPEED
> systems.

There is no mention of RGMII here or RGMII delays. Given the mess that
the AST2600 is, i would expect to see some explanation how that has
been solved.

Andrew