On Mon, Feb 03, 2025 at 06:09:41PM +0100, Nikita Yushchenko wrote: > It was observed on spider board that with upstream kernel, PHY > auto-negotiation takes almost 1 second longer than with renesas BSP > kernel. This was tracked down to upstream kernel allowing more PHY modes > than renesas BSP kernel. > > To avoid that effect when possible, always set max_speed to not more > than phy_interface allows. Please could you provide more information about the hardware. Is the PHY more capable than the MAC? When you have multi Gigi PHYs, the phy-mode is often taken to be the starting point. But when the PHY has negotiated a link, it will tell the MAC what PHY mode it needs to swap to, e.g from SGMII to 2500BaseX, etc. You should only need max-speed when you have a PHY which can do more than the MAC. Also, phylink handles this a lot better than phylib. So you might want to change rswitch to phylink, especially if you have link speeds > 1G. Andrew
