When interfacing with a Broadcom PHY, request the auto-power down, DLL
disable and IDDQ-SR modes to be enabled.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we are using a dedicated PHY driver (not the Generic PHY driver)
chances are that it is going to configure RGMII delays and do that in a
way that is incompatible with our incorrect interpretation of the
phy_interface value.

Add a quirk in order to reverse the PHY_INTERFACE_MODE_RGMII to the
value of PHY_INTERFACE_MODE_RGMII_ID such that the MAC continues to be
configured the way it used to be, but the PHY driver can account for
adding delays. Conversely when PHY_INTERFACE_MODE_RGMII_TXID is
specified, return PHY_INTERFACE_MODE_RGMII_RXID to the PHY since we will
have enabled a TXC MAC delay (id_mode_dis=0, meaning there is a delay
inserted).

This is not considered a bug fix at this point since it only affects
Broadcom STB platforms shipping with a Device Tree blob that is not
updatable in the field (quite a few devices out there) and which was
generated using the scripted Device Tree environment shipped with those
platforms' SDK.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some internal PHY's have their events like link change reported by the
MAC interrupt. We have PHY_IGNORE_INTERRUPT to deal with this scenario.
I'm not too happy with this name. We don't ignore interrupts, typically
there is no interrupt exposed at a PHY level. So let's rename it to
PHY_MAC_INTERRUPT. This is in line with phy_mac_interrupt(), which is
called from the MAC interrupt handler to handle PHY events.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UniMAC is integrated into multiple Broadcom's Ethernet controllers so
use a shared header file for it and avoid some code duplication.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NDoug Berger <opendmb@gmail.com>
Link: https://lore.kernel.org/r/20210107180051.1542-2-zajec5@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

As noted in commit 28c2d1a7 ("net: bcmgenet: enable loopback
during UniMAC sw_reset") the UniMAC must be clocked at least 5
cycles while the sw_reset is asserted to ensure a clean reset.

That commit enabled local loopback to provide an Rx clock from the
GENET sourced Tx clk. However, when connected in MII mode the Tx
clk is sourced by the PHY so if an EPHY is not supplying clocks
(e.g. when the link is down) the UniMAC does not receive the
necessary clocks.

This commit extends the sw_reset window until the PHY reports that
the link is up thereby ensuring that the clocks are being provided
to the MAC to produce a clean reset.

One consequence is that if the system attempts to enter a Wake on
LAN suspend state when the PHY link has not been active the MAC
may not have had a chance to initialize cleanly. In this case, we
remove the sw_reset and enable the WoL reception path as normal
with the hope that the PHY will provide the necessary clocks to
drive the WoL blocks if the link becomes active after the system
has entered suspend.

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 3a55402c.

This is not a good solution when connecting to an external switch
that may not support the isolation of the TXC signal resulting in
output driver contention on the pin.

A different solution is necessary.
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Outdated Raspberry Pi 4 firmware might configure the external PHY as
rgmii although the kernel currently sets it as rgmii-rxid. This makes
connections unreliable as ID_MODE_DIS is left enabled. To avoid this,
explicitly clear that bit whenever we don't need it.

Fixes: da388022 ("net: bcmgenet: Add RGMII_RXID support")
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The unimac mdio driver falls back to scanning the
entire bus if its given an appropriate mask. In ACPI
mode we expect that the system is well behaved and
conforms to recent versions of the specification.

We then utilize phy_find_first(), and
phy_connect_direct() to find and attach to the
discovered phy during net_device open. While its
apparently possible to build a genet based device
with multiple phys on a single mdio bus, this works
for current machines. Further, this driver makes
a number of assumptions about the platform device,
mac, mdio and phy all being 1:1. Lastly, It also
avoids having to create references across the ACPI
namespace hierarchy.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The DT phy mode is similar to what we want for ACPI
lets factor it out of the of path, and change the
of_ call to device_.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds the missing support for the PHY mode RGMII_RXID.
It's necessary for the Raspberry Pi 4.
Signed-off-by: NStefan Wahren <wahrenst@gmx.net>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The register access in bcmgenet_mii_config() is a little bit opaque and
not easy to extend. In preparation for the missing RGMII PHY modes
move all the phy name assignments into the switch statement and the
register access to the end of the function. This make the code easier
to read and extend.
Signed-off-by: NStefan Wahren <wahrenst@gmx.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 1f515486.

This commit improved the chances of the umac resetting cleanly by
ensuring that the PHY was restored to its normal operation prior
to resetting the umac. However, there were still cases when the
PHY might not be driving a Tx clock to the umac during this window
(e.g. when the PHY detects no link).

The previous commit now ensures that the unimac receives clocks
from the MAC during its reset window so this commit is no longer
needed. This commit also has an unintended negative impact on the
MDIO performance of the UniMAC MDIO interface because it is used
before the MDIO interrupts are reenabled, so it should be removed.
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As noted in commit 28c2d1a7 ("net: bcmgenet: enable loopback
during UniMAC sw_reset") the UniMAC must be clocked while sw_reset
is asserted for its state machines to reset cleanly.

The transmit and receive clocks used by the UniMAC are derived from
the signals used on its PHY interface. The bcmgenet MAC can be
configured to work with different PHY interfaces including MII,
GMII, RGMII, and Reverse MII on internal and external interfaces.
Unfortunately for the UniMAC, when configured for MII the Tx clock
is always driven from the PHY which places it outside of the direct
control of the MAC.

The earlier commit enabled a local loopback mode within the UniMAC
so that the receive clock would be derived from the transmit clock
which addressed the observed issue with an external GPHY disabling
it's Rx clock. However, when a Tx clock is not available this
loopback is insufficient.

This commit implements a workaround that leverages the fact that
the MAC can reliably generate all of its necessary clocking by
enterring the external GPHY RGMII interface mode with the UniMAC in
local loopback during the sw_reset interval. Unfortunately, this
has the undesirable side efect of the RGMII GTXCLK signal being
driven during the same window.

In most configurations this is a benign side effect as the signal
is either not routed to a pin or is already expected to drive the
pin. The one exception is when an external MII PHY is expected to
drive the same pin with its TX_CLK output creating output driver
contention.

This commit exploits the IEEE 802.3 clause 22 standard defined
isolate mode to force an external MII PHY to present a high
impedance on its TX_CLK output during the window to prevent any
contention at the pin.

The MII interface is used internally with the 40nm internal EPHY
which agressively disables its clocks for power savings leading to
incomplete resets of the UniMAC and many instabilities observed
over the years. The workaround of this commit is expected to put
an end to those problems.

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before this change of_get_phy_mode() returned an enum,
phy_interface_t. On error, -ENODEV etc, is returned. If the result of
the function is stored in a variable of type phy_interface_t, and the
compiler has decided to represent this as an unsigned int, comparision
with -ENODEV etc, is a signed vs unsigned comparision.

Fix this problem by changing the API. Make the function return an
error, or 0 on success, and pass a pointer, of type phy_interface_t,
where the phy mode should be stored.

v2:
Return with *interface set to PHY_INTERFACE_MODE_NA on error.
Add error checks to all users of of_get_phy_mode()
Fixup a few reverse christmas tree errors
Fixup a few slightly malformed reverse christmas trees

v3:
Fix 0-day reported errors.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It turns out that the "Workaround for putting the PHY in IDDQ mode"
used by the internal EPHYs on 40nm Set-Top Box chips when powering
down puts the interface to the GENET MAC in a state that can cause
subsequent MAC resets to be incomplete.

Rather than restore the forced soft reset when powering up internal
PHYs, this commit moves the invocation of phy_init_hw earlier in
the MAC initialization sequence to just before the MAC reset in the
open and resume functions. This allows the interface to be stable
and allows the MAC resets to be successful.

The bcmgenet_mii_probe() function is split in two to accommodate
this. The new function bcmgenet_mii_connect() handles the first
half of the functionality before the MAC initialization, and the
bcmgenet_mii_config() function is extended to provide the remaining
PHY configuration following the MAC initialization.

Fixes: 484bfa15 ("Revert "net: bcmgenet: Software reset EPHY after power on"")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RGMII_MODE_EN bit value was 0 for GENET versions 1 through 3, and
became 6 for GENET v4 and above, account for that difference.

Fixes: aa09677c ("net: bcmgenet: add MDIO routines")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

phydev->dev_flags is entirely dependent on the PHY device driver which
is going to be used, setting the internal GENET PHY revision in those
bits only makes sense when drivers/net/phy/bcm7xxx.c is the PHY driver
being used.

Fixes: 487320c5 ("net: bcmgenet: communicate integrated PHY revision to PHY driver")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NEnrico Weigelt <info@metux.net>
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All users of the fixed_phy_add() pass -1 as GPIO number
to the fixed phy driver, and all users of fixed_phy_register()
pass -1 as GPIO number as well, except for the device
tree MDIO bus.

Any new users should create a proper device and pass the
GPIO as a descriptor associated with the device so delete
the GPIO argument from the calls and drop the code looking
requesting a GPIO in fixed_phy_add().

In fixed phy_register(), investigate the "fixed-link"
node and pick the GPIO descriptor from "link-gpios" if
this property exists. Move the corresponding code out
of of_mdio.c as the fixed phy code anyways requires
OF to be in use.
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are a few MAC/PHYs combinations which now support > 1Gbps. These
may need to make use of link modes with bits > 31. Thus their
supported PHY features or advertised features cannot be implemented
using the current bitmap in a u32. Convert to using a linkmode bitmap,
which can support all the currently devices link modes, and is future
proof as more modes are added.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the new of_get_compatible_child() helper to lookup the mdio child
node instead of using of_find_compatible_node(), which searches the
entire tree from a given start node and thus can return an unrelated
(i.e. non-child) node.

This also addresses a potential use-after-free (e.g. after probe
deferral) as the tree-wide helper drops a reference to its first
argument (i.e. the node of the device being probed).

Fixes: aa09677c ("net: bcmgenet: add MDIO routines")
Cc: stable <stable@vger.kernel.org>     # 3.15
Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>

On GENETv5, there is a hardware issue which prevents the GENET hardware
from generating a link UP interrupt when the link is operating at
10Mbits/sec. Since we do not have any way to configure the link
detection logic, fallback to polling in that case.

Fixes: 42138085 ("net: bcmgenet: add support for the GENETv5 hardware")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The phy supported speed is being used to determine if the MAC should
be configured to 100 or 1G. The masking logic is broken. Instead, look
at 1G supported speeds to enable 1G MAC support.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many Ethernet MAC drivers want to limit the PHY to only advertise a
maximum speed of 100Mbs or 1Gbps. Rather than using a mask, make use
of the helper function phy_set_max_speed().
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using the fixed PHY with GENET (e.g. MOCA) the PHY link
status can be determined from the internal link status captured
by the MAC. This allows the PHY state machine to use the correct
link state with the fixed PHY even if MAC link event interrupts
are missed when the net device is opened.

Fixes: 8d88c6eb ("net: bcmgenet: enable MoCA link state change detection")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove platform_device_put() call after platform_device_unregister()
from function bcmgenet_mii_exit(), otherwise, we will call
platform_device_put() twice.

Fixes: 9a4e7969 ("net: bcmgenet: utilize generic Broadcom UniMAC MDIO controller driver")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Acked-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that the software reset of the PHY has been removed it is no
longer necessary to retain a private pointer to the phydev for
use when the PHY is detached (which isn't generally safe anyway).

The driver now uses the phydev member attached to the net_device.

For ethtool commands that have a PHY component, an explicit check
is made to prevent accessing an invalid phydev pointer when one
is not attached (e.g. interface is down).
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With commit f7d72996e222 ("net: bcmgenet: enable loopback during
UniMAC sw_reset") it is no longer necessary to force the software
reset of the internal EPHY before resetting the UniMAC to ensure a
clean reset.

Therefore this commit reverts commit 5dbebbb4 ("net: bcmgenet:
Software reset EPHY after power on").
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 28b45910 ("net: bcmgenet: Remove init parameter
from bcmgenet_mii_config") because in the process of moving from
dev_info() to dev_info_once() we essentially lost the helpful printed
messages once the second instance of the driver is loaded.
dev_info_once() does not actually print the message once per device
instance, but once period.

Fixes: 28b45910 ("net: bcmgenet: Remove init parameter from bcmgenet_mii_config")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bcmgenet_mii_init() has an error path which is strictly identical to the
unwinding that bcmgenet_mii_exit() does, so have bcmgenet_mii_init()
utilize bcmgenet_mii_exit() for that.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that we have fully migrated to the mdio-bcm-unimac driver, drop the
legacy MDIO bus code which did duplicate a fair amount of code.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update the GENET driver to register an UniMAC MDIO bus controller for
the GENET internal MDIO bus, update the platform data code to attach the
PHY to the correct MDIO bus controller.

The Device Tree portion of the code is mostly left unmodified since the
lookup/binding is done via phandles and Device Tree nodes which are much
more flexible in locating and binding PHYs to their respective MDIO bus
controllers.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The PHY library now supports an "internal" phy-mode, thus making our
custom parsing code now unnecessary.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 6ac3ce82 ("net: bcmgenet: Remove excessive PHY reset")
removed the bcmgenet_mii_reset() function from bcmgenet_power_up() and
bcmgenet_internal_phy_setup() functions.  In so doing it broke the reset
of the internal PHY devices used by the GENETv1-GENETv3 which required
this reset before the UniMAC was enabled.  It also broke the internal
GPHY devices used by the GENETv4 because the config_init that installed
the AFE workaround was no longer occurring after the reset of the GPHY
performed by bcmgenet_phy_power_set() in bcmgenet_internal_phy_setup().
In addition the code in bcmgenet_internal_phy_setup() related to the
"enable APD" comment goes with the bcmgenet_mii_reset() so it should
have also been removed.

Commit bd4060a6 ("net: bcmgenet: Power on integrated GPHY in
bcmgenet_power_up()") moved the bcmgenet_phy_power_set() call to the
bcmgenet_power_up() function, but failed to remove it from the
bcmgenet_internal_phy_setup() function.  Had it done so, the
bcmgenet_internal_phy_setup() function would have been empty and could
have been removed at that time.

Commit 5dbebbb4 ("net: bcmgenet: Software reset EPHY after power on")
was submitted to correct the functional problems introduced by
commit 6ac3ce82 ("net: bcmgenet: Remove excessive PHY reset"). It
was included in v4.4 and made available on 4.3-stable. Unfortunately,
it didn't fully revert the commit because this bcmgenet_mii_reset()
doesn't apply the soft reset to the internal GPHY used by GENETv4 like
the previous one did. This prevents the restoration of the AFE work-
arounds for internal GPHY devices after the bcmgenet_phy_power_set() in
bcmgenet_internal_phy_setup().

This commit takes the alternate approach of removing the unnecessary
bcmgenet_internal_phy_setup() function which shouldn't have been in v4.3
so that when bcmgenet_mii_reset() was restored it should have only gone
into bcmgenet_power_up().  This will avoid the problems while also
removing the redundancy (and hopefully some of the confusion).

Fixes: 6ac3ce82 ("net: bcmgenet: Remove excessive PHY reset")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit adds support for the GENETv5 implementation.

The GENETv5 reports a major version of 6 instead of 5 so compensate
for this when verifying the configuration of the driver.  Also the
EPHY revision is now contained in the MDIO registers of the PHY so
the EPHY revision of 0 in GENET_VER_FMT is expected for GENETv5.
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make sure to deregister and free any fixed-link PHY registered using
of_phy_register_fixed_link() on probe errors and on driver unbind.

Note that we're still leaking any fixed-link PHY registered in the
non-OF probe path.

Fixes: 9abf0c2b ("net: bcmgenet: use the new fixed PHY helpers")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make sure to drop the reference taken by of_phy_find_device() when
initialising MOCA PHYs.

Fixes: 6ac9de5f ("net: bcmgenet: Register link_update callback for
all MoCA PHYs")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 62469c76 ("net: ethernet: bcmgenet: use phydev
from struct net_device") because it causes GENETv1/2/3 adapters to
expose the following behavior after an ifconfig down/up sequence:

PING fainelli-linux (10.112.156.244): 56 data bytes
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.352 ms
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.472 ms (DUP!)
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.496 ms (DUP!)
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.517 ms (DUP!)
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.536 ms (DUP!)
64 bytes from 10.112.156.244: seq=1 ttl=61 time=1.557 ms (DUP!)
64 bytes from 10.112.156.244: seq=1 ttl=61 time=752.448 ms (DUP!)

This was previously fixed by commit 5dbebbb4 ("net: bcmgenet:
Software reset EPHY after power on") but the commit we are reverting was
essentially making this previous commit void, here is why.

Without commit 62469c76 we would have the following scenario after
an ifconfig down then up sequence:

- bcmgenet_open() calls bcmgenet_power_up() to make sure the PHY is
  initialized *before* we get to initialize the UniMAC, this is
  critical to ensure the PHY is in a correct state, priv->phydev is
  valid, this code executes fine

- second time from bcmgenet_mii_probe(), through the normal
  phy_init_hw() call (which arguably could be optimized out)

Everything is fine in that case. With commit 62469c76, we would have
the following scenario to happen after an ifconfig down then up
sequence:

- bcmgenet_close() calls phy_disonnect() which makes dev->phydev become
  NULL

- when bcmgenet_open() executes again and calls bcmgenet_mii_reset() from
  bcmgenet_power_up() to initialize the internal PHY, the NULL check
  becomes true, so we do not reset the PHY, yet we keep going on and
  initialize the UniMAC, causing MAC activity to occur

- we call bcmgenet_mii_reset() from bcmgenet_mii_probe(), but this is
  too late, the PHY is botched, and causes the above bogus pings/packets
  transmission/reception to occur
Reported-by: NJaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NPhilippe Reynes <tremyfr@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>