This is a note to let you know that I've just added the patch titled net: phy: broadcom: stub c45 read/write for 54810 to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-phy-broadcom-stub-c45-read-write-for-54810.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 096516d092d54604d590827d05b1022c8f326639 Mon Sep 17 00:00:00 2001 From: Justin Chen <justin.chen@xxxxxxxxxxxx> Date: Sat, 12 Aug 2023 21:41:47 -0700 Subject: net: phy: broadcom: stub c45 read/write for 54810 From: Justin Chen <justin.chen@xxxxxxxxxxxx> commit 096516d092d54604d590827d05b1022c8f326639 upstream. 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@xxxxxxxxxxxx> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/1691901708-28650-1-git-send-email-justin.chen@xxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> [florian: resolved conflicts in 4.14] Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/phy/broadcom.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/drivers/net/phy/broadcom.c +++ b/drivers/net/phy/broadcom.c @@ -403,6 +403,17 @@ static int bcm5482_read_status(struct ph return err; } +static int bcm54810_read_mmd(struct phy_device *phydev, int devnum, u16 regnum) +{ + return -EOPNOTSUPP; +} + +static int bcm54810_write_mmd(struct phy_device *phydev, int devnum, u16 regnum, + u16 val) +{ + return -EOPNOTSUPP; +} + static int bcm5481_config_aneg(struct phy_device *phydev) { struct device_node *np = phydev->mdio.dev.of_node; @@ -650,6 +661,8 @@ static struct phy_driver broadcom_driver .name = "Broadcom BCM54810", .features = PHY_GBIT_FEATURES, .flags = PHY_HAS_INTERRUPT, + .read_mmd = bcm54810_read_mmd, + .write_mmd = bcm54810_write_mmd, .config_init = bcm54xx_config_init, .config_aneg = bcm5481_config_aneg, .read_status = genphy_read_status, Patches currently in stable-queue which might be from justin.chen@xxxxxxxxxxxx are queue-4.14/net-phy-broadcom-stub-c45-read-write-for-54810.patch