RE: [PATCH net v3] r8152: Use BMSR to detect the link state

[Hayes Wang <hayeswang@realtek.com>]

Linmao Li <lilinmao@kylinos.cn>
> Sent: Monday, October 26, 2026 9:24 AM
> To: andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@kernel.org;
> kuba@kernel.org; pabeni@redhat.com
> Cc: Hayes Wang <hayeswang@realtek.com>; nic_swsd
> <nic_swsd@realtek.com>; Chih Kai Hsu <hsu.chih.kai@realtek.com>;
> mail@birger-koblitz.de; zhangxiangqian@kylinos.cn; linux-usb@vger.kernel.org;
> netdev@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org;
> Linmao Li <lilinmao@kylinos.cn>
> Subject: [PATCH net v3] r8152: Use BMSR to detect the link state
> 
> 
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> 
> r8152 detects carrier from PLA_PHYSTATUS without reading BMSR, so
> BMSR_LSTATUS can remain latched low after link up. Since
> commit f6f2e946aa4d ("net: mii: Fix the Speed display when the network
> cable is not connected"), the first speed query can then report
> SPEED_UNKNOWN, which applications such as NetworkManager may cache
> until the next carrier change.
> 
> Use BMSR_LSTATUS in set_carrier() so a latched link down can turn
> carrier off after the link has recovered. If BMSR reports down but
> PLA_PHYSTATUS reports up, reschedule the link work to read the current
> state without waiting for another notification.
> 
> Tested on an RTL8153B: NetworkManager reported 1000 Mb/s after 3 of 3
> rebinds, instead of an unknown speed.
> 
> Fixes: f6f2e946aa4d ("net: mii: Fix the Speed display when the network cable is
> not connected")
> Cc: stable@vger.kernel.org
> Suggested-by: Hayes Wang <hayeswang@realtek.com>
> Signed-off-by: Linmao Li <lilinmao@kylinos.cn>

Reviewed-by: Hayes Wang <hayeswang@realtek.com>

Best Regards,
Hayes