Re: [PATCH net-next 2/4 v4] net: dsa: rtl8366rb: Support flood control

On Thu, Sep 30, 2021 at 11:09 AM Alvin Šipraga [off-list ref] wrote:

On 9/29/21 11:57 PM, Vladimir Oltean wrote:

quoted

On Wed, Sep 29, 2021 at 11:03:47PM +0200, Linus Walleij wrote:

quoted

quoted

Now that we have implemented bridge flag handling we can easily
support flood control as well so let's do it.

quoted

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+/* Storm registers are for flood control
+ *
+ * 02e2 and 02e3 are defined in the header for the RTL8366RB API
+ * but there are no usage examples. The implementation only activates
+ * the filter per port in the CTRL registers.

The "filter" word bothers me a bit.
Are these settings applied on ingress or on egress? If you have
RTL8366RB_STORM_BC_CTRL == BIT(0) | BIT(1), and a broadcast packet is
received on port 2, then

(a) is it received or dropped?
(b) is it forwarded to port 0 and 1?
(c) is it forwarded to port 3?

Linus, are you sure these STORM_... registers are the right ones to
control flooding? The doc from Realtek[1] talks briefly about this storm
control feature, but it seems to be related to rate limiting, not actual
flooding behaviour.

You're probably right. I'll just drop this patch for now.

Yours,
Linus Walleij