[ Upstream commit 096516d092d54604d590827d05b1022c8f326639 ] The 54810 does not support c45. The mmd_phy_indirect accesses return arbirtary values leading to odd behavior like saying it supports EEE when it doesn't. We also see that reading/writing these non-existent MMD registers leads to phy instability in some cases. Fixes: b14995ac2527 ("net: phy: broadcom: Add BCM54810 PHY entry") Signed-off-by: Justin Chen <justin.chen@broadcom.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/1691901708-28650-1-git-send-email-justin.chen@broadcom.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>