[PATCH net v3] net: mdio: aspeed: add dummy read to avoid read-after-write issue

[Andrew Lunn]

On Thu, Dec 11, 2025 at 02:24:58PM +0800, Jacky Chou wrote:
> The Aspeed MDIO controller may return incorrect data when a read operation
> follows immediately after a write. Due to a controller bug, the subsequent
> read can latch stale data, causing the polling logic to terminate earlier
> than expected.
> 
> To work around this hardware issue, insert a dummy read after each write
> operation. This ensures that the next actual read returns the correct
> data and prevents premature polling exit.
> 
> This workaround has been verified to stabilize MDIO transactions on
> affected Aspeed platforms.
> 
> Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
> Signed-off-by: Jacky Chou <jacky_chou at aspeedtech.com>

Reviewed-by: Andrew Lunn <andrew at lunn.ch>

    Andrew