[PATCH net] net: stmmac: resume PHY before reopening the interface on MTU change

[Jakub Raczynski]

On Tue, Jul 07, 2026 at 06:21:46PM +0200, Stefan Agner wrote:
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -5884,6 +5884,15 @@
>  
>  		__stmmac_release(dev);
>  
> +		/* phylink_stop() in __stmmac_release() suspends the PHY.
> +		 * IEEE 802.3 allows PHYs to stop their receive clock while
> +		 * powered down, but the DMA software reset performed by
> +		 * stmmac_hw_setup() requires a running receive clock.
> +		 * Resume the PHY, as on system resume, to ensure its clocks
> +		 * are running before reopening the interface.
> +		 */
> +		phylink_prepare_resume(priv->phylink);

Does it work without warnings? Nothing in dmesg?
phylink_prepare_resume() does have ASSERT_RTNL() which is not called anywhere.

BR
Jakub Raczynski