Re: [PATCH net-next v7 04/14] net: lan966x: add FDMA LLP register write helper

From: Simon Horman

Date: Wed Sep 23 2026 - 05:13:13 EST


On Fri, Sep 18, 2026 at 01:33:56PM +0200, Daniel Machon wrote:
> The FDMA Link List Pointer (LLP) register points to the first DCB in the
> chain and must be written before the channel is activated. This tells
> the FDMA engine where to begin DMA transfers.
>
> Move the LLP register writes from the channel start/activate functions
> into the allocation functions and introduce a shared
> lan966x_fdma_llp_configure() helper. This is needed because the upcoming
> PCIe FDMA path writes ATU-translated addresses to the LLP registers
> instead of DMA addresses. Keeping the writes in the shared
> start/activate path would overwrite these translated addresses.
>
> Tested-by: Herve Codina <herve.codina@xxxxxxxxxxx>
> Signed-off-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>