Re: [PATCH net-next v7 1/4] net: macb: queue tie-off or disable during WOL suspend
From: Andrew Lunn
Date: Sat Jun 22 2024 - 15:14:56 EST
On Fri, Jun 21, 2024 at 10:27:32AM +0530, Vineeth Karumanchi wrote:
> When GEM is used as a wake device, it is not mandatory for the RX DMA
> to be active. The RX engine in IP only needs to receive and identify
> a wake packet through an interrupt. The wake packet is of no further
> significance; hence, it is not required to be copied into memory.
> By disabling RX DMA during suspend, we can avoid unnecessary DMA
> processing of any incoming traffic.
>
> During suspend, perform either of the below operations:
>
> - tie-off/dummy descriptor: Disable unused queues by connecting
> them to a looped descriptor chain without free slots.
>
> - queue disable: The newer IP version allows disabling individual queues.
>
> Co-developed-by: Harini Katakam <harini.katakam@xxxxxxx>
> Signed-off-by: Harini Katakam <harini.katakam@xxxxxxx>
> Signed-off-by: Vineeth Karumanchi <vineeth.karumanchi@xxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew