is actually "active high". Thanks for Troy Kisky for pointing
that out.

Since the patch is in linux-next, this patch is incremental and doesn't
replace the original patch.
Signed-off-by: NBernhard Walle <bernhard@bwalle.de>
Acked-by: NFugang Duan <fugang.duan@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need that for a custom hardware that needs the reverse reset
sequence.
Signed-off-by: NBernhard Walle <bernhard@bwalle.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unmap initial buffer on error.
Don't free skb until it has been unmapped.
Move cbd_bufaddr assignment closer to the mapping function.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If you don't own it, you shouldn't write to it.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only the interrupt routine processes this condition.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need for complex macros every time we need to activate
a queue. Also, no need to call skb_get_queue_mapping when we already
know which queue it is using.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reduces code and gains speed.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When first initialized, cur_tx points to the 1st
entry in the queue, and dirty_tx points to the last.
At this point, fec_enet_get_free_txdesc_num will
return tx_ring_size -2. If tx_ring_size -2 entries
are now queued, then fec_enet_get_free_txdesc_num
should return 0, but it returns tx_ring_size instead.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On an overrun, the other flags are not
valid, so don't check them.

Also, don't pass bad frames up the stack.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Setting the FTRL register will stop the fec from
trying to use multiple receive buffers.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Arnd Bergmann points out, using CONFIG_ARCH_MXC and/or SOC_IMX28
is wrong if some other ARM platform uses this device - the operation
of the driver would depend on an unrelated ARM platform that might
or might not be set for multi-platform kernels.

Prior to my previous patch, any other platforms using it would have
been broken already due to having the cbd_datlen/cbd_sc fields in
the wrong order, but byte ordering correctly, so no such platforms
can exist and work today.

In any case, it seems likely that only Freescale SoCs use this part,
and those are little-endian on ARM, so CONFIG_ARM is safe for them.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver treats the device descriptors as CPU-endian, which appears
to be correct with the default endianness on both ARM (typically LE)
and PowerPC (typically BE) SoCs, indicating that the hardware block
is generated differently. Add endianness annotations and byteswaps as
necessary.

It's not clear that the ifdef there really is correct and shouldn't
just be #ifdef CONFIG_ARM, but I also can't test on anything but the
i.MX6 HummingBoard where this gets it working with a BE kernel.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than have drivers directly manipulate the mii_bus structure,
provide and API for registering and unregistering devices on an MDIO
bus, and performing lookups.
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>

Have mdio_alloc() create the array of interrupt numbers, and
initialize it to POLLING. This is what most MDIO drivers want, so
allowing code to be removed from the drivers.
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>

Many Ethernet drivers contain the same netdev_info() print statement
about the attached phy. Move it into the phy device code. Additionally
add a varargs function which can be used to append additional
information.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

in case of error no need to set num_tx and num_rx = 1, because in case of error
these variables will remain unchanged by of_property_read_u32 ie 1 only
Signed-off-by: NSaurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are in a context where we can sleep, and the FEC PHY reset gpio
may be on an I2C expander. Use the cansleep() variant when
setting the GPIO value.

Based on a patch from Russell King for pci-mvebu.c.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to have FEATURES_NEED_QUIESCE defined as we
can simply use NETIF_F_RXCSUM instead as done in other parts
of the driver.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There exist one issue by below case that case system hang:
ifconfig eth0 down
ifconfig eth0 hw ether 00:10:19:19:81:19

After eth0 down, all fec clocks are gated off. In the .fec_set_mac_address()
function, it will set new MAC address to registers, which causes system hang.

So it needs to add netif status check to avoid registers access when clocks are
gated off. Until eth0 up the new MAC address are wrote into related registers.

V2:
As Lucas Stach's suggestion, add a comment in the code to explain why it needed.

CC: Lucas Stach <l.stach@pengutronix.de>
CC: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If fec MDIO write method succeeds its return value comes from
call to pm_runtime_get_sync().
But pm_runtime_get_sync() can also return 1.

In case of Micrel KSZ9031 PHY this value will then
be returned along the call chain of phy_write() ->
ksz9031_extended_write() -> ksz9031_center_flp_timing() ->
ksz9031_config_init() -> phy_init_hw() -> phy_attach_direct() ->
phy_connect_direct().

Then phy_connect() will cast it into a pointer using ERR_PTR(),
which then fec_enet_mii_probe() will try to dereference
resulting in an oops.

Fix it by normalizing return value of pm_runtime_get_sync()
to be zero if positive in MDIO write method.

Fixes: 8fff755e ("net: fec: Ensure clocks are enabled while using mdio bus")
Signed-off-by: NMaciej Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The patch just to re-submit the patch "db3421c1" because the
patch "4d494cdc" remove the change.

Clear any pending receive interrupt before we process a pending packet.
This helps to avoid any spurious interrupts being raised after we have
fully cleaned the receive ring, while still allowing an interrupt to be
raised if we receive another packet.

The position of this is critical: we must do this prior to reading the
next packet status to avoid potentially dropping an interrupt when a
packet is still pending.
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than re-initialising the entire completion on every mdio access,
use reinit_completion() which only resets the completion count.  This
avoids possible reinitialisation of the contained spinlock and waitqueue
while they may be in use (eg, mid-completion.)

Such an event could occur if there's a long delay in interrupt handling
causing the mdio accessor to time out, then a second access comes in
while the interrupt handler on a different CPU has called complete().
Another scenario where this has been observed is while locking has
been missing at the phy layer, allowing concurrent attempts to access
the MDIO bus.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to use the IS_ERR_VALUE() macro for checking
the return value from pm_runtime_* functions.

Just do a simple negative test instead.

The semantic patch that makes this change is available
in scripts/coccinelle/api/pm_runtime.cocci.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we transmit a fragmented skb, we may run into a race like the
following scenario (assume txq->cur_tx is next to txq->dirty_tx):
           cpu 0                                          cpu 1
  fec_enet_txq_submit_skb
    reserve a bdp for the first fragment
    fec_enet_txq_submit_frag_skb
       update the bdp for the other fragment
       update txq->cur_tx
                                                   fec_enet_tx_queue
                                                     bdp = fec_enet_get_nextdesc(txq->dirty_tx, fep, queue_id);
                                                     This bdp is the bdp reserved for the first segment. Given
                                                     that this bdp BD_ENET_TX_READY bit is not set and txq->cur_tx
                                                     is already pointed to a bdp beyond this one. We think this is a
                                                     completed bdp and try to reclaim it.
    update the bdp for the first segment
    update txq->cur_tx

So we shouldn't update the txq->cur_tx until all the update to the
bdps used for fragments are performed. Also add the corresponding
memory barrier to guarantee that the update to the bdps, dirty_tx and
cur_tx performed in the proper order.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The clocks are initially active and thus the device is marked active.
This still keeps the PM refcount at 0, the pm_runtime_put_autosuspend()
call at the end of probe then leaves us with an invalid refcount of -1,
which in turn leads to the device staying in suspended state even though
netdev open had been called.

Fix this by initializing the refcount to be coherent with the initial
device status.

Fixes:
8fff755e (net: fec: Ensure clocks are enabled while using mdio bus)
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Tested-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a switch is attached to the mdio bus, the mdio bus can be used
while the interface is not open. If the IPG clock is not enabled, MDIO
reads/writes will simply time out.

Add support for runtime PM to control this clock. Enable/disable this
clock using runtime PM, with open()/close() and mdio read()/write()
function triggering runtime PM operations. Since PM is optional, the
IPG clock is enabled at probe and is no longer modified by
fec_enet_clk_enable(), thus if PM is not enabled in the kernel, it is
guaranteed the clock is running when MDIO operations are performed.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Cc: tyler.baker@linaro.org
Cc: fabio.estevam@freescale.com
Cc: shawn.guo@linaro.org
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Tested-by: NTyler Baker <tyler.baker@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function frees resources and cancels delayed work item that
have been initialized in fec_ptp_init().

Use this to do proper error handling if something goes wrong in
probe function after fec_ptp_init has been called.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So it gets freed when the device is going away.
This fixes a DMA memory leak on driver probe() fail and driver
remove().
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 6c3e921b.

commit 6c3e921b ("net: fec: Ensure clocks are enabled while using mdio
 bus") prevents the kernel to boot on mx6 boards, so let's revert it.
Reported-by: NTyler Baker <tyler.baker@linaro.org>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a switch is attached to the mdio bus, the mdio bus can be used
while the interface is not open. If the IPG clock is not enabled, MDIO
reads/writes will simply time out.

Add support for runtime PM to control this clock. Enable/disable this
clock using runtime PM, with open()/close() and mdio read()/write()
function triggering runtime PM operations. Since PM is optional, the
IPG clock is enabled at probe and is no longer modified by
fec_enet_clk_enable(), thus if PM is not enabled in the kernel, it is
guaranteed the clock is running when MDIO operations are performed.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Not all silicon implementations of the Freescale FEC hardware module
have the RACC (Receive Accelerator Function) register, so we should not
be trying to access it on those that don't. Currently none of the ColdFire
based parts with a FEC have it.

Support for RACC was introduced by commit 4c09eed9 ("net: fec: Enable imx6
enet checksum acceleration"). A fix was introduced in commit d1391930
("net: fec: Fix build for MCF5272") that disables its use on the ColdFire
M5272 part, but it doesn't fix the general case of other ColdFire parts.

To fix we create a quirk flag, FEC_QUIRK_HAS_RACC, and check it before
working with the RACC register.
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Below case causes mii bus probe failed:
ifconfig eth0 down -> suspend/resume with Mega/fax mix off -> ifconfig eth0 up

In i.MX6SX/i.MX7D chip, Mega/fast mix off feature is supported that means most of
SOC power will be off including ENET MAC for power saving. Once ENET MAC power
off, all initialized MAC registers reset to default, so in the case, it must
init MAC prior to mii bus probe.
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This enables the ethtool's "-d" and "--register-dump"
options for fec devices.
Signed-off-by: NPhilippe Reynes <tremyfr@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RGMII-ID uses an internal delay within the transmitter or receiver. This
feature is phy specific. The rest of the communication is normal RGMII.

So the fec driver has to check for all RGMII modes, not only
'PHY_INTERFACE_MODE_RGMII'.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The FEC modules used on i.MX28 and newer have a register to tune the MDIO
output hold time that should be at least 10 ns. Up to now this value was not
explicitly set and so resulted in less hold time if the fec clock was
faster than 100 MHz.

This was noticed on an i.MX28 machine that uses an input clock of ~150
Mhz which resulted in unreliable communication with a Marvell switch.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 2b995f63.

Панов Андрей reported the following regression:

"Commit 2b995f63 in 4.0.0-rc3 introduces a
nasty bug in transmit, corrupting packets.

To reproduce:

$ dd if=/dev/zero of=zeros bs=1M count=20
$ md5sum -b zeros
8f4e33f3dc3e414ff94e5fb6905cba8c *zeros

This checksum is correct.

Copy file "zeros" to another host with NFS, and it gets corrupted, checksum is
changed.
File should be big, small amounts of transmit isn't affected.

I use an i.MX6 Quad board.

If this commit is reverted, all works fine."
Reported-by: NПанов Андрей <rockford@yandex.ru>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current driver support receive VLAN CTAG HW acceleration feature
(NETIF_F_HW_VLAN_CTAG_RX) through software simulation. There calls the
api .skb_copy_to_linear_data_offset() to skip the VLAN tag, but there
have overlap between the two memory data point range. The patch just fix
the issue.

V2:
Michael Grzeschik suggest to use memmove() instead of skb_copy_to_linear_data_offset().
Reported-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Fixes: 1b7bde6d ("net: fec: implement rx_copybreak to improve rx performance")
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the driver is removed (e.g. using unbind through sysfs), the
clocks get disabled twice, once on fec_enet_close and once on
fec_drv_remove. Since the clocks are enabled only once, this leads
to a warning:

WARNING: CPU: 0 PID: 402 at drivers/clk/clk.c:992 clk_core_disable+0x64/0x68()

Remove the call to fec_enet_clk_enable in fec_drv_remove to balance
the clock enable/disable calls again. This has been introduce by
e8fcfcd5 ("net: fec: optimize the clock management to save power").
Signed-off-by: NStefan Agner <stefan@agner.ch>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When do suspend/resume stress test, some log shows "rcv is not +last".
The issue is that enet suspend will disable phy clock, phy link down,
after resume back, enet MAC redo initial and ready to tx/rx packet,
but phy still is not ready which is doing auto-negotiation. When phy
link is not up, don't schdule napi soft irq.

[Peter]
It has fixed kernel panic after long time suspend/resume test
with nfs rootfs.

[ 8864.429458] fec 2188000.ethernet eth0: rcv is not +last
[ 8864.434799] fec 2188000.ethernet eth0: rcv is not +last
[ 8864.440088] fec 2188000.ethernet eth0: rcv is not +last
[ 8864.445424] fec 2188000.ethernet eth0: rcv is not +last
[ 8864.450782] fec 2188000.ethernet eth0: rcv is not +last
[ 8864.456111] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 8864.464225] pgd = 80004000
[ 8864.466997] [00000000] *pgd=00000000
[ 8864.470627] Internal error: Oops: 17 [#1] SMP ARM
[ 8864.475353] Modules linked in: evbug
[ 8864.479006] CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.0.0-rc1-00044-g7a2a1d2 #234
[ 8864.486854] Hardware name: Freescale i.MX6 SoloX (Device Tree)
[ 8864.492709] task: be069380 ti: be07a000 task.ti: be07a000
[ 8864.498137] PC is at memcpy+0x80/0x330
[ 8864.501919] LR is at gro_pull_from_frag0+0x34/0xa8
[ 8864.506735] pc : [<802bb080>]    lr : [<8057c204>]    psr: 00000113
[ 8864.506735] sp : be07bbd4  ip : 00000010  fp : be07bc0c
[ 8864.518235] r10: 0000000e  r9 : 00000000  r8 : 809c7754
[ 8864.523479] r7 : 809c7754  r6 : bb43c040  r5 : bd280cc0  r4 : 00000012
[ 8864.530025] r3 : 00000804  r2 : fffffff2  r1 : 00000000  r0 : bb43b83c
[ 8864.536575] Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[ 8864.543904] Control: 10c5387d  Table: bd14c04a  DAC: 00000015
[ 8864.549669] Process ksoftirqd/0 (pid: 3, stack limit = 0xbe07a210)
[ 8864.555869] Stack: (0xbe07bbd4 to 0xbe07c000)
[ 8864.560250] bbc0:                                              bd280cc0 bb43c040 809c7754
[ 8864.568455] bbe0: 809c7754 bb43b83c 00000012 8057c204 00000000 bd280cc0 bd8a0718 00000003
[ 8864.576658] bc00: be07bc5c be07bc10 8057ebf0 8057c1dc 00000000 00000000 8057ecc4 bef59760
[ 8864.584863] bc20: 00000002 bd8a0000 be07bc64 809c7754 00000000 bd8a0718 bd280cc0 bd8a0000
[ 8864.593066] bc40: 00000000 0000001c 00000000 bd8a0000 be07bc74 be07bc60 8057f148 8057eb90
[ 8864.601268] bc60: bf0810a0 00000000 be07bcf4 be07bc78 8044e7b4 8057f12c 00000000 8007df6c
[ 8864.609470] bc80: bd8a0718 00000040 00000000 bd280a80 00000002 00000019 bd8a0600 bd8a1214
[ 8864.617672] bca0: bd8a0690 bf0810a0 00000000 00000000 bd8a1000 00000000 00000027 bd280cc0
[ 8864.625874] bcc0: 80062708 800625cc 000943db bd8a0718 00000001 000d1166 00000040 be7c1ec0
[ 8864.634077] bce0: 0000012c be07bd00 be07bd3c be07bcf8 8057fc98 8044e3ac 809c2ec0 3ddff000
[ 8864.642280] bd00: be07bd00 be07bd00 be07bd08 be07bd08 00000000 00000020 809c608c 00000003
[ 8864.650481] bd20: 809c6080 40000001 809c6088 00200100 be07bd84 be07bd40 8002e690 8057fac8
[ 8864.658684] bd40: be07bd64 be07bd50 00000001 04208040 000d1165 0000000a be07bd84 809c0d7c
[ 8864.666885] bd60: 00000000 809c6af8 00000000 00000001 be008000 00000000 be07bd9c be07bd88
[ 8864.675087] bd80: 8002eb64 8002e564 00000125 809c0d7c be07bdc4 be07bda0 8006f100 8002eaac
[ 8864.683291] bda0: c080e10c be07bde8 809c6c6c c080e100 00000002 00000000 be07bde4 be07bdc8
[ 8864.691492] bdc0: 800087a0 8006f098 806f2934 20000013 ffffffff be07be1c be07be44 be07bde8
[ 8864.699695] bde0: 800133a4 80008784 00000001 00000001 00000000 00000000 be7c1680 00000000
[ 8864.707896] be00: be0cfe00 bd93eb40 00000002 00000000 00000000 be07be44 be07be00 be07be30
[ 8864.716098] be20: 8006278c 806f2934 20000013 ffffffff be069380 be7c1680 be07be7c be07be48
[ 8864.724300] be40: 80049cfc 806f2910 00000001 00000000 80049cb4 00000000 be07be7c be7c1680
[ 8864.732502] be60: be3289c0 be069380 bd23b600 be0cfe00 be07bebc be07be80 806ed614 80049c68
[ 8864.740706] be80: be07a000 0000020a 809c608c 00000003 00000001 8002e858 be07a000 be035740
[ 8864.748907] bea0: 00000000 00000001 809d4598 00000000 be07bed4 be07bec0 806edd0c 806ed440
[ 8864.757110] bec0: be07a000 be07a000 be07bee4 be07bed8 806edd68 806edcf0 be07bef4 be07bee8
[ 8864.765311] bee0: 8002e860 806edd34 be07bf24 be07bef8 800494b0 8002e828 be069380 00000000
[ 8864.773512] bf00: be035780 be035740 8004938c 00000000 00000000 00000000 be07bfac be07bf28
[ 8864.781715] bf20: 80045928 80049398 be07bf44 00000001 00000000 be035740 00000000 00030003
[ 8864.789917] bf40: dead4ead ffffffff ffffffff 80a2716c 80b59b00 00000000 8088c954 be07bf5c
[ 8864.798120] bf60: be07bf5c 00000000 00000000 dead4ead ffffffff ffffffff 80a2716c 00000000
[ 8864.806320] bf80: 00000000 8088c954 be07bf88 be07bf88 be035780 8004584c 00000000 00000000
[ 8864.814523] bfa0: 00000000 be07bfb0 8000ed10 80045858 00000000 00000000 00000000 00000000
[ 8864.822723] bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 8864.830925] bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 5ffbb5f7 f9fcf5e7
[ 8864.839115] Backtrace:
[ 8864.841631] [<8057c1d0>] (gro_pull_from_frag0) from [<8057ebf0>] (dev_gro_receive+0x6c/0x3f8)
[ 8864.850173]  r6:00000003 r5:bd8a0718 r4:bd280cc0 r3:00000000
[ 8864.855958] [<8057eb84>] (dev_gro_receive) from [<8057f148>] (napi_gro_receive+0x28/0xac)
[ 8864.864152]  r10:bd8a0000 r9:00000000 r8:0000001c r7:00000000 r6:bd8a0000 r5:bd280cc0
[ 8864.872115]  r4:bd8a0718
[ 8864.874713] [<8057f120>] (napi_gro_receive) from [<8044e7b4>] (fec_enet_rx_napi+0x414/0xc74)
[ 8864.883167]  r5:00000000 r4:bf0810a0
[ 8864.886823] [<8044e3a0>] (fec_enet_rx_napi) from [<8057fc98>] (net_rx_action+0x1dc/0x2ec)
[ 8864.895016]  r10:be07bd00 r9:0000012c r8:be7c1ec0 r7:00000040 r6:000d1166 r5:00000001
[ 8864.902982]  r4:bd8a0718
[ 8864.905570] [<8057fabc>] (net_rx_action) from [<8002e690>] (__do_softirq+0x138/0x2c4)
[ 8864.913417]  r10:00200100 r9:809c6088 r8:40000001 r7:809c6080 r6:00000003 r5:809c608c
[ 8864.921382]  r4:00000020
[ 8864.923966] [<8002e558>] (__do_softirq) from [<8002eb64>] (irq_exit+0xc4/0x138)
[ 8864.931289]  r10:00000000 r9:be008000 r8:00000001 r7:00000000 r6:809c6af8 r5:00000000
[ 8864.939252]  r4:809c0d7c
[ 8864.941841] [<8002eaa0>] (irq_exit) from [<8006f100>] (__handle_domain_irq+0x74/0xe8)
[ 8864.949688]  r4:809c0d7c r3:00000125
[ 8864.953342] [<8006f08c>] (__handle_domain_irq) from [<800087a0>] (gic_handle_irq+0x28/0x68)
[ 8864.961707]  r9:00000000 r8:00000002 r7:c080e100 r6:809c6c6c r5:be07bde8 r4:c080e10c
[ 8864.969597] [<80008778>] (gic_handle_irq) from [<800133a4>] (__irq_svc+0x44/0x5c)
[ 8864.977097] Exception stack(0xbe07bde8 to 0xbe07be30)
[ 8864.982173] bde0:                   00000001 00000001 00000000 00000000 be7c1680 00000000
[ 8864.990377] be00: be0cfe00 bd93eb40 00000002 00000000 00000000 be07be44 be07be00 be07be30
[ 8864.998573] be20: 8006278c 806f2934 20000013 ffffffff
[ 8865.003638]  r7:be07be1c r6:ffffffff r5:20000013 r4:806f2934
[ 8865.009447] [<806f2904>] (_raw_spin_unlock_irq) from [<80049cfc>] (finish_task_switch+0xa0/0x160)
[ 8865.018334]  r4:be7c1680 r3:be069380
[ 8865.021993] [<80049c5c>] (finish_task_switch) from [<806ed614>] (__schedule+0x1e0/0x5dc)
[ 8865.030098]  r8:be0cfe00 r7:bd23b600 r6:be069380 r5:be3289c0 r4:be7c1680
[ 8865.036942] [<806ed434>] (__schedule) from [<806edd0c>] (preempt_schedule_common+0x28/0x44)
[ 8865.045307]  r9:00000000 r8:809d4598 r7:00000001 r6:00000000 r5:be035740 r4:be07a000
[ 8865.053197] [<806edce4>] (preempt_schedule_common) from [<806edd68>] (_cond_resched+0x40/0x48)
[ 8865.061822]  r4:be07a000 r3:be07a000
[ 8865.065472] [<806edd28>] (_cond_resched) from [<8002e860>] (run_ksoftirqd+0x44/0x64)
[ 8865.073252] [<8002e81c>] (run_ksoftirqd) from [<800494b0>] (smpboot_thread_fn+0x124/0x190)
[ 8865.081550] [<8004938c>] (smpboot_thread_fn) from [<80045928>] (kthread+0xdc/0xf8)
[ 8865.089133]  r10:00000000 r9:00000000 r8:00000000 r7:8004938c r6:be035740 r5:be035780
[ 8865.097097]  r4:00000000 r3:be069380
[ 8865.100752] [<8004584c>] (kthread) from [<8000ed10>] (ret_from_fork+0x14/0x24)
[ 8865.107990]  r7:00000000 r6:00000000 r5:8004584c r4:be035780
[ 8865.113767] Code: e320f000 e4913004 e4914004 e4915004 (e4916004)
[ 8865.120006] ---[ end trace b0a4c6bd499288ca ]---
[ 8865.124697] Kernel panic - not syncing: Fatal exception in interrupt
[ 8865.131084] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Cc: [v3.19+] stable@vger.kernel.org
Tested-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>