Re: [PATCH net-next v6 2/7] net: dsa: Add DSA driver for Hirschmann Hellcreek switches

On Tue, Oct 06, 2020 at 12:13:04PM +0200, Kurt Kanzenbach wrote:

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+static const struct hellcreek_platform_data de1soc_r1_pdata = {
+	.num_ports	 = 4,
+	.is_100_mbits	 = 1,
+	.qbv_support	 = 1,
+	.qbv_on_cpu_port = 1,

Why does this matter?

Because Qbv on the CPU port is a feature and not all switch variants
have that. It will matter as soon as TAPRIO is implemented.

How do you plan to install a tc-taprio qdisc on the CPU port?

That's an issue to be sorted out.

Do you have a compelling use case for tc-taprio on the CPU port though?
I've been waiting for someone to put one on the table.
If it's just "nice to have", I don't think that DSA will change just to
accomodate that. The fact that the CPU port doesn't have a net device is
already pretty much the established behavior.