On Thu, 2018-04-19 at 17:02 +0530, Naresh Kamboju wrote: > On 12 April 2018 at 00:05, Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > 4.9-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Leonard Crestez <leonard.crestez@xxxxxxx> > > > > [ Upstream commit 79e498a9c7da0737829ff864aae44df434105676 ] > > > > These bits seem to be lost after a suspend/resume cycle so just set them > > again. Do this by splitting the handling of these bits into a function > > that is also called on resume. > > > > This patch fixes ethernet suspend/resume on imx6ul-14x14-evk boards. > > > > Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx> > > Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> > > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> > > Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > --- > > drivers/net/phy/micrel.c | 42 ++++++++++++++++++++++++++++-------------- > > 1 file changed, 28 insertions(+), 14 deletions(-) > arm32 x15 device booting 4.9 kernel shows kernel warning and > the network is not working on the device. > > Linux version 4.9.95-rc1 (buildslave@lkft-01) (gcc version 6.2.1 20161016 > (Linaro GCC 6.2-2016.11) ) #1 SMP Tue Apr 17 19:12:22 UTC 2018 > > Boot log kernel crash log: > -------------------------- > [ 13.766589] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready > [ 13.805441] net eth0: initializing cpsw version 1.15 (0) > [ 13.930334] Unable to handle kernel NULL pointer dereference at > virtual address 00000008 > [ 13.982009] PC is at kszphy_config_reset+0x1c/0x150 > [ 13.986909] LR is at kszphy_resume+0x24/0x64 > LAVA job id: https://lkft.validation.linaro.org/scheduler/job/187429#L3341 Looking at this dump I'm guessing that phydev->priv is NULL at the start of kszphy_config_reset and this really shouldn't be happening. The phydev->priv field is initialized by kszphy_probe but your particular phy (KSZ9031) in linux-4.9.y does not seem to have .probe = kszphy_probe assigned in the struct phy_driver ksphy_driver array. In upstream this was added by commit bfe72442578b ("net: phy: micrel: fix crash when statistic requested for KSZ9031 phy"). The message for that patch claims to fix a kernel crash on this command: ethtool --phy-statistics eth0 Looking at the code this issue should affect linux-4.9.y on your board. Naresh: can you please check? Commit bfe72442578b was not tagged or selected for stable but it seems to be a more serious issue. BTW, the original patch was 2nd of a series, actually making imx6ul- 4x14-evk correctly suspend/resume ethernet in linux-4.9.y also requires 1st commit e6f4292ae0a1 ("ARM: dts: imx6ul-14x14-evk: Add ksz8081 phy properties"). But this is not a terribly important fix. -- Regards, Leonard