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Date:   Fri, 10 Jun 2022 22:44:07 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Cc:     Samuel Mendoza-Jonas <sam@mendozajonas.com>,
        "David S . Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        openbmc@lists.ozlabs.org
Subject: Re: [PATCH v2 0/6] Configurable VLAN mode for NCSI driver
Message-ID: <20220610224407.4e58dc5a@kernel.org>
In-Reply-To: <6f067302-74a8-702f-bf38-4477a805a528@linux.intel.com>
References: <20220610165940.2326777-1-jiaqing.zhao@linux.intel.com>
        <20220610130903.0386c0d9@kernel.org>
        <3c9fa928-f416-3526-be23-12644d18db3b@linux.intel.com>
        <20220610214506.74c3f89c@kernel.org>
        <6f067302-74a8-702f-bf38-4477a805a528@linux.intel.com>
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On Sat, 11 Jun 2022 13:18:51 +0800 Jiaqing Zhao wrote:
> All ncsi devices uses the same driver as they uses same command set,
> so the driver doesn't know what modes are supported. And in current
> driver, the vlan related parameters are configured when registering
> the device, adding an ncsi-netlink command to do so seems to be
> unsuitable.

Maybe you could draw a diagram? NC-SI is a bit confusing.

> And adding a netlink command requires extra application in userspace
> to switch the mode. In my opinion, it would be more user-friendly to
> make it usable on boot.

Unfortunately convenience is not reason to start adding system config
into DT.

> Netdev also does not work as the ncsi device itself does not have
> its own netdev, the netdev comes from the mac device. For different
> vlan modes, the netdev feature set of its parent mac device are the
> same.

You say that, yet the command handling already takes into account the
VLAN list:

	if (list_empty(&ndp->vlan_vids)) {

which come from the MAC netdev. What's wrong with setting the filtering
mode based on NETIF_F_HW_VLAN_CTAG_FILTER ?