Date:   Tue, 4 Jan 2022 06:53:26 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Henning Schild <henning.schild@siemens.com>,
        Aaron Ma <aaron.ma@canonical.com>
Cc:     <davem@davemloft.net>, <hayeswang@realtek.com>, <tiwai@suse.de>,
        <linux-usb@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] net: usb: r8152: Add MAC passthrough support for more
 Lenovo Docks
Message-ID: <20220104065326.2a73f674@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net>
In-Reply-To: <20220104123814.32bf179e@md1za8fc.ad001.siemens.net>
References: <20211116141917.31661-1-aaron.ma@canonical.com>
        <20220104123814.32bf179e@md1za8fc.ad001.siemens.net>
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On Tue, 4 Jan 2022 12:38:14 +0100 Henning Schild wrote:
> This patch is wrong and taking the MAC inheritance way too far. Now any
> USB Ethernet dongle connected to a Lenovo USB Hub will go into
> inheritance (which is meant for docks).
> 
> It means that such dongles plugged directly into the laptop will do
> that, or travel adaptors/hubs which are not "active docks".
> 
> I have USB-Ethernet dongles on two desks and both stopped working as
> expected because they took the main MAC, even with it being used at the
> same time. The inheritance should (if at all) only be done for clearly
> identified docks and only for one r8152 instance ... not all. Maybe
> even double checking if that main PHY is "plugged" and monitoring it to
> back off as soon as it is.
> 
> With this patch applied users can not use multiple ethernet devices
> anymore ... if some of them are r8152 and connected to "Lenovo" ...
> which is more than likely!
> 
> Reverting that patch solved my problem, but i later went to disabling
> that very questionable BIOS feature to disable things for good without
> having to patch my kernel.
> 
> I strongly suggest to revert that. And if not please drop the defines of
> 
> > -		case DEVICE_ID_THINKPAD_THUNDERBOLT3_DOCK_GEN2:
> > -		case DEVICE_ID_THINKPAD_USB_C_DOCK_GEN2:  
> 
> And instead of crapping out with "(unnamed net_device) (uninitialized):
> Invalid header when reading pass-thru MAC addr" when the BIOS feature
> is turned off, one might want to check
> DSDT/WMT1/ITEM/"MACAddressPassThrough" which is my best for asking the
> BIOS if the feature is wanted.

Thank you for the report!

Aaron, will you be able to fix this quickly? 5.16 is about to be
released.