Subject: Re: [PATCH net-next] net: dsa: tag_rtl4_a: Drop bit 9 from egress frames

From: DENG Qingfang <[email-masked]>
Date: Wed, 15 Sep 2021 15:19:01 +0800

On Mon, Sep 13, 2021 at 04:31:56PM +0200, Linus Walleij wrote:
> This drops the code setting bit 9 on egress frames on the
> Realtek "type A" (RTL8366RB) frames.

FYI, on RTL8366S, bit 9 on egress frames is disable learning.

> This bit was set on ingress frames for unknown reason,

I think it could be the reason why the frame is forwarded to the CPU.

> and was set on egress frames as the format of ingress
> and egress frames was believed to be the same. As that
> assumption turned out to be false, and since this bit
> seems to have zero effect on the behaviour of the switch
> let's drop this bit entirely.
> 
> Signed-off-by: Linus Walleij <[email-masked]>