Re: [PATCH v2] mdio: aspeed: Fix "Link is Down" issue

On Thu, Nov 25, 2021 at 10:44:32AM +0800, Dylan Hung wrote:

The issue happened randomly in runtime. The message "Link is Down" is popped but soon it recovered to "Link is Up".

The "Link is Down" results from the incorrect read data for reading the PHY register via MDIO bus. The correct sequence for reading the data shall be:

1. fire the command
2. wait for command done (this step was missing)
3. wait for data idle
4. read data from data register

Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed") Cc: stable@vger.kernel.org Reviewed-by: Joel Stanley joel@jms.id.au Signed-off-by: Dylan Hung dylan_hung@aspeedtech.com

Reviewed-by: Andrew Lunn andrew@lunn.ch

Andrew