[U-Boot] [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: e55047ec51a6 ("cmd: mdio: Switch to generic helpers when accessing the registers") Reported-by: Alex Marginean alexm.osslist@gmail.com Signed-off-by: Vladimir Oltean olteanv@gmail.com --- cmd/mdio.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/cmd/mdio.c b/cmd/mdio.c index efe8c9ef0954..5e219f699d8d 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,

On 5/30/2019 3:08 AM, Vladimir Oltean wrote:
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: e55047ec51a6 ("cmd: mdio: Switch to generic helpers when accessing the registers") Reported-by: Alex Marginean alexm.osslist@gmail.com Signed-off-by: Vladimir Oltean olteanv@gmail.com
cmd/mdio.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/cmd/mdio.c b/cmd/mdio.c index efe8c9ef0954..5e219f699d8d 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,
Reviewed-by: Alex Marginean alexm.osslist@gmail.com
Thanks! Alex

On Wed, May 29, 2019 at 8:53 PM Vladimir Oltean olteanv@gmail.com wrote:
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: e55047ec51a6 ("cmd: mdio: Switch to generic helpers when accessing the registers") Reported-by: Alex Marginean alexm.osslist@gmail.com Signed-off-by: Vladimir Oltean olteanv@gmail.com
Acked-by: Joe Hershberger joe.hershberger@ni.com

Hi Vladimir,
https://patchwork.ozlabs.org/patch/1107478/ was applied to http://git.denx.de/?p=u-boot/u-boot-net.git
Thanks! -Joe
participants (3)
-
Alex Marginean
-
Joe Hershberger
-
Vladimir Oltean