From b4c20f20adad8d246b95be5bebacb730462c8c01 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 30 May 2019 03:08:32 +0300 Subject: [PATCH] cmd: mdio: Fix access to arbitrary PHY addresses Alex reported the following: " I'm doing some MDIO work on a freescale/NXP platform and I bumped into errors with this command: => mdio r emdio#3 5 3 Reading from bus emdio#3 "Synchronous Abort" handler, esr 0x8600000e elr: ffffffff862b8000 lr : 000000008200cce4 (reloc) ... mdio list does not list any PHYs currently because ethernet is using DM and the interfaces are not probed at this time. The PHY does exist on the bus though. The above scenario works with this commit reverted: e55047ec51a662c12ed53ff543ec7cdf158b2137 cmd: mdio: Switch to generic helpers when accessing the registers The current code using generic helpers only works for PHYs that have been registered and show up in bus->phymap and crashes for arbitrary IDs. I find it useful to allow reading from other addresses over MDIO too, certainly helpful for people debugging MDIO on various boards. " Fix this by reverting to use the raw MDIO bus operations in case there is no PHY probed based on DT at the specified address. This restores the old behavior for these PHYs, which means that the newly introduced MMD-over-C22 helpers won't be available for them, but at least they will be accessible again without crashing the system. Fixes: commit e55047ec51a6 ("cmd: mdio: Switch to generic helpers when accessing the registers") Reported-by: Alex Marginean Signed-off-by: Vladimir Oltean Reviewed-by: Alex Marginean Acked-by: Joe Hershberger --- cmd/mdio.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/cmd/mdio.c b/cmd/mdio.c index efe8c9ef09..5e219f699d 100644 --- a/cmd/mdio.c +++ b/cmd/mdio.c @@ -54,7 +54,10 @@ static int mdio_write_ranges(struct mii_dev *bus, for (devad = devadlo; devad <= devadhi; devad++) { for (reg = reglo; reg <= reghi; reg++) { - if (!extended) + if (!phydev) + err = bus->write(bus, addr, devad, + reg, data); + else if (!extended) err = phy_write_mmd(phydev, devad, reg, data); else @@ -88,7 +91,9 @@ static int mdio_read_ranges(struct mii_dev *bus, for (reg = reglo; reg <= reghi; reg++) { int val; - if (!extended) + if (!phydev) + val = bus->read(bus, addr, devad, reg); + else if (!extended) val = phy_read_mmd(phydev, devad, reg); else val = phydev->drv->readext(phydev, addr, -- 2.25.1