[PATCH net-next v5 1/7] net: phylink: add PHY_F_RXC_ALWAYS_ON to PHY dev flags

[Andrew Lunn]

On Fri, Mar 01, 2024 at 04:34:58PM +0100, Romain Gantois wrote:
> From: Russell King <linux at armlinux.org.uk>
> 
> Some MAC controllers (e.g. stmmac) require their connected PHY to
> continuously provide a receive clock signal. This can cause issues in two
> cases:
> 
>   1. The clock signal hasn't been started yet by the time the MAC driver
>      initializes its hardware. This can make the initialization fail, as in
>       the case of the rzn1 GMAC1 driver.
>   2. The clock signal is cut during a power saving event. By the time the
>      MAC is brought back up, the clock signal is still not active since
>      phylink_start hasn't been called yet. This brings us back to case 1.
> 
> If a PHY driver reads this flag, it should ensure that the receive clock
> signal is started as soon as possible, and that it isn't brought down when
> the PHY goes into suspend.
> 
> Signed-off-by: Russell King <linux at armlinux.org.uk>
> [rgantois: commit log]
> Signed-off-by: Romain Gantois <romain.gantois at bootlin.com>

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

    Andrew