This is a note to let you know that I've just added the patch titled net: fec: Fix phy_device lookup for phy_reset_after_clk_enable() to the 4.19-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-fec-fix-phy_device-lookup-for-phy_reset_after_clk_enable.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Oct 17 12:48:24 PM CEST 2020 From: Marek Vasut <marex@xxxxxxx> Date: Sat, 10 Oct 2020 11:10:00 +0200 Subject: net: fec: Fix phy_device lookup for phy_reset_after_clk_enable() From: Marek Vasut <marex@xxxxxxx> [ Upstream commit 64a632da538a6827fad0ea461925cedb9899ebe2 ] The phy_reset_after_clk_enable() is always called with ndev->phydev, however that pointer may be NULL even though the PHY device instance already exists and is sufficient to perform the PHY reset. This condition happens in fec_open(), where the clock must be enabled first, then the PHY must be reset, and then the PHY IDs can be read out of the PHY. If the PHY still is not bound to the MAC, but there is OF PHY node and a matching PHY device instance already, use the OF PHY node to obtain the PHY device instance, and then use that PHY device instance when triggering the PHY reset. Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support") Signed-off-by: Marek Vasut <marex@xxxxxxx> Cc: Christoph Niedermaier <cniedermaier@xxxxxxxxxxxxxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: NXP Linux Team <linux-imx@xxxxxxx> Cc: Richard Leitner <richard.leitner@xxxxxxxxxxx> Cc: Shawn Guo <shawnguo@xxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1897,6 +1897,27 @@ static int fec_enet_mdio_write(struct mi return ret; } +static void fec_enet_phy_reset_after_clk_enable(struct net_device *ndev) +{ + struct fec_enet_private *fep = netdev_priv(ndev); + struct phy_device *phy_dev = ndev->phydev; + + if (phy_dev) { + phy_reset_after_clk_enable(phy_dev); + } else if (fep->phy_node) { + /* + * If the PHY still is not bound to the MAC, but there is + * OF PHY node and a matching PHY device instance already, + * use the OF PHY node to obtain the PHY device instance, + * and then use that PHY device instance when triggering + * the PHY reset. + */ + phy_dev = of_phy_find_device(fep->phy_node); + phy_reset_after_clk_enable(phy_dev); + put_device(&phy_dev->mdio.dev); + } +} + static int fec_enet_clk_enable(struct net_device *ndev, bool enable) { struct fec_enet_private *fep = netdev_priv(ndev); @@ -1923,7 +1944,7 @@ static int fec_enet_clk_enable(struct ne if (ret) goto failed_clk_ref; - phy_reset_after_clk_enable(ndev->phydev); + fec_enet_phy_reset_after_clk_enable(ndev); } else { clk_disable_unprepare(fep->clk_enet_out); if (fep->clk_ptp) { @@ -2938,7 +2959,7 @@ fec_enet_open(struct net_device *ndev) * phy_reset_after_clk_enable() before because the PHY wasn't probed. */ if (reset_again) - phy_reset_after_clk_enable(ndev->phydev); + fec_enet_phy_reset_after_clk_enable(ndev); if (fep->quirks & FEC_QUIRK_ERR006687) imx6q_cpuidle_fec_irqs_used(); Patches currently in stable-queue which might be from marex@xxxxxxx are queue-4.19/net-fec-fix-phy_device-lookup-for-phy_reset_after_clk_enable.patch queue-4.19/net-fec-fix-phy-init-after-phy_reset_after_clk_enable.patch