This patch introduces the group structure. The elements of this
structure are the interrupt lines, their corresponding names,
the register memory map.
The elements for this group are factored out from the gfar_private
structure. The introduction of group structure will help in
providing support for newer versions of etsec.

Currently, the support is present only for single group and
single tx/rx queues.
Signed-off-by: NSandeep Gopalpet <Sandeep.Kumar@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces per tx and per rx queue structures.
Earlier the members of these structures were inside the
gfar_private structure.

Moving forward if we want to support multiple queues, we need
to refactor the gfar_private structure so that introduction of
multiple queues is easier.
Signed-off-by: NSandeep Gopalpet <Sandeep.Kumar@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some OF platform drivers are missing module device tables, so they won't
load automatically on boot. This patch fixes the issue by adding proper
MODULE_DEVICE_TABLE() macros to the drivers.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Thanks to various cleanups and refactorings this is now straightforward:
convert the gianfar driver to dev_pm_ops, plus add ->restore() callback
that will fully reinitialize MAC internal registers and BDs.

Note that I kept legacy suspend/resume callbacks so that this patch
doesn't depend on PowerPC changes (i.e. dev_pm_ops support for OF
platform drivers).
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After hibernation we want to just reinitialize BDs, no need to allocate
anything. So, factor out BDs initialization code from
gfar_alloc_skb_resourses().

Also, teach gfar_init_bds() to reuse already allocated RX SKBs, i.e.
just call gfar_init_rxbdp() if a SKB was already allocated and mapped.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We want to just reinitialize RX BDs after hibernation, no need to
map the skb->data again. So let's factor gfar_init_rxbdp() out of
gfar_new_rxbdp().
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For hibernation we want to call gfar_init_mac() without need to
free/allocate_skb_resources sequence, so save the DMA address into a
private struct, and move tbase/rbase initialization to gfar_init_mac().
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Two new functions implemented: gfar_alloc_skb_resources() and
gfar_init_mac(). We'll use gfar_init_mac() for restoring after
hibernation.

The patch just moves the code around, there should be no functional
changes.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

startup_gfar() sets the wrap bit for the last rxbd just after
gfar_new_rxbdp() call, which is issued for all rxbds. And
gfar_new_rxbdp() has the following check already:

	if (bdp == priv->rx_bd_base + priv->rx_ring_size - 1)
		lstatus |= BD_LFLAG(RXBD_WRAP);

So we don't need to set the bit again.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove dma_free_coherent() from stop_gfar() and gfar_start() calls,
place it into free_skb_resources(). That makes SKB resources management
more understandable, plus free_skb_resources() will be used as a cleanup
routine for gfar_alloc_skb_resources() that will be implemented soon.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're going to split the startup_gfar() into 3 separate functions,
so let's cleanup the code a little bit so that cosmetic changes
won't distract attention from logical ones.

- Remove needless casts (e.g. (struct sk_buff **)kmalloc());
- Turn 'unsigned long vaddr;' into 'void *vaddr', to avoid casting;
- Add new 'struct device *dev' variable as a shorthand for
  '&priv->ofdev->dev' that is used all over the place, also rename
  'struct net_device *dev' to 'struct net_device *ndev';
- Turn printk(KERN_ERR ...) to pr_err(...), which is shorter;
- Don't return bogus -1 (i.e. -EPERM) when request_irq() fails;
- Turn '&priv->regs->' to just '&regs->'.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reported by Michael Guntsche <mike@it-loops.com>

--------------------
Commit
38bddf04 gianfar: gfar_remove needs to call unregister_netdev()

breaks the build of the gianfar driver because "dev" is undefined in
this function. To quickly test rc9 I changed this to priv->ndev but I do
not know if this is the correct one.
--------------------
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch solves the problem that the Oops(BUG_ON) occurs by rmmod.

	# rmmod gianfar_driver
	------------[ cut here ]------------
	Kernel BUG at c01fec48 [verbose debug info unavailable]
	Oops: Exception in kernel mode, sig: 5 [#1]
	MPC837x MDS
	Modules linked in: gianfar_driver(-) usb_storage scsi_wait_scan
	NIP: c01fec48 LR: c01febf4 CTR: c01feba8
	REGS: dec5bd60 TRAP: 0700   Tainted: G        W   (2.6.31-rc2)
	MSR: 00029032 <EE,ME,CE,IR,DR>  CR: 22000424  XER: 20000000
	TASK = dec4cac0[1135] 'rmmod' THREAD: dec5a000
	GPR00: 00000002 dec5be10 dec4cac0 dfba1820 c035d444 c035d478 ffffffff 00000000
	GPR08: 0000002b 00000001 dfba193c 00000001 22000424 10019b34 1ffcb000 00000000
	GPR16: 10012008 00000000 bf82ebe0 100017ec bf82ebec bf82ebe8 bf82ebd0 00000880
	GPR24: 00000000 bf82ebf0 c03532f0 c03532e4 c036b594 dfba183c dfba1800 dfba1820
	NIP [c01fec48] free_netdev+0xa0/0xb8
	LR [c01febf4] free_netdev+0x4c/0xb8
	Call Trace:
	[dec5be10] [c01febf4] free_netdev+0x4c/0xb8 (unreliable)
	[dec5be30] [e105f290] gfar_remove+0x50/0x68 [gianfar_driver]
	[dec5be40] [c01ec534] of_platform_device_remove+0x30/0x44
	[dec5be50] [c0181760] __device_release_driver+0x68/0xc8
	[dec5be60] [c0181868] driver_detach+0xa8/0xac
	[dec5be80] [c0180814] bus_remove_driver+0x9c/0xd8
	[dec5bea0] [c0181efc] driver_unregister+0x60/0x98
	[dec5beb0] [c01ec650] of_unregister_driver+0x14/0x24
	[dec5bec0] [e10631bc] gfar_exit+0x18/0x4bc [gianfar_driver]
	[dec5bed0] [c0047584] sys_delete_module+0x16c/0x228
	[dec5bf40] [c00116bc] ret_from_syscall+0x0/0x38
	--- Exception: c01 at 0xff3669c
	    LR = 0x10000f34
	Instruction dump:
	409e0024 a07e00c0 7c63f050 4be74429 80010024 bba10014 38210020 7c0803a6
	4e800020 68000003 3160ffff 7d2b0110 <0f090000> 38000004 387e01f0 901e01d4
	---[ end trace 8c595bcd37230a0f ]---
	 localhost kernel: ------------[ cut here ]------------

Signed-off-by: Toru UCHIYAMA uchiyama.toru@jp.fujitsu.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If vlan has been enabled. ifdown followed by ifup will lost hardware
related state.

Also remove duplicated operation in gfar_vlan_rx_register().
Signed-off-by: NYong Zhang <yong.zhang0@gmail.com>
Acked-by: NDai Haruki <dai.haruki@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit fe192a49 ("Rework gianfar
driver to use of_mdio infrastructure") the fixed-link support is
broken, the driver oopses at init_phy():

  Unable to handle kernel paging request for data at address 0x000000e4
  Faulting instruction address: 0xc01cf298
  Oops: Kernel access of bad area, sig: 11 [#1]
  [...]
  NIP [c01cf298] init_phy+0x80/0xdc
  LR [c01cf250] init_phy+0x38/0xdc
  Call Trace:
  [cf81fe80] [c01d1cf8] gfar_enet_open+0x6c/0x19c
  [cf81fea0] [c024494c] dev_open+0xfc/0x134
  [cf81fec0] [c0242edc] dev_change_flags+0x84/0x1ac
  [cf81fee0] [c0399ee0] ic_open_devs+0x168/0x2d8
  [cf81ff20] [c039b2e8] ip_auto_config+0x90/0x2a4
  [cf81ff60] [c0003884] do_one_initcall+0x34/0x1a8

This patch fixes the oops, and removes phy_node checks, and adds a call
to of_phy_connect_fixed_link() if a phy isn't attached..

Also, remove an old fixed-link code that we don't use any longer.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The use of it was converted to %pM, but the variable
stuck -- remove it now to not cause spurious warnings.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

alloc_etherdev() used to install default implementations of these
operations, but they must now be explicitly installed in struct
net_device_ops.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 0fd56bb5 ("gianfar:
Add support for skb recycling"), gianfar puts skbuffs that are in
the rx ring back onto the recycle list as-is in case there was a
receive error, but this breaks the following invariant: that all
skbuffs on the recycle list have skb->data = skb->head + NET_SKB_PAD.

The RXBUF_ALIGNMENT realignment done in gfar_new_skb() will be done
twice on skbuffs recycled in this way, causing there not to be enough
room in the skb anymore to receive a full packet, eventually leading
to an skb_over_panic from gfar_clean_rx_ring() -> skb_put().

Resetting the skb->data pointer to skb->head + NET_SKB_PAD before
putting the skb back onto the recycle list restores the mentioned
invariant, and should fix this issue.
Reported-by: NMichael Guntsche <mike@it-loops.com>
Tested-by: NMichael Guntsche <mike@it-loops.com>
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

cacheable_memzero() is completely overkill for the clearing out the FCB
block which is only 8-bytes.  The compiler should easily optimize this
with memset.  Additionally, cacheable_memzero() only exists on ppc32 and
thus breaks builds of gianfar on ppc64.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch simplifies the driver by making use of more common code.

Tested on Freescale MPC8349emitxgp eval board
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After a transmit timed out, the reset task will be called, which will free the
allocated resources(stop_gfar). If gfar_poll will be called before the
resources get allocated again gfar_clean_tx_ring will call
dev_kfree_skb_any(NULL).

Example crash:

ops: Kernel access of bad area, sig: 11 [#1]
PREEMPT RSBBA100
Modules linked in:
NIP: c01a10c4 LR: c013b254 CTR: c013c038
REGS: c02e7d20 TRAP: 0300   Not tainted  (2.6.27.20)
MSR: 00001032 <ME,IR,DR>  CR: 24000082  XER: 20000000
DAR: 000000a0, DSISR: 20000000
TASK = c02ce578[0] 'swapper' THREAD: c02e6000
GPR00: 000000a0 c02e7dd0 c02ce578 00000000 00000040 00000001 c02ec1c0 
00001032
GPR08: c080d1e0 df9ea800 00000000 00000000 24000082 ffffffff 0404f000 
00000000
GPR16: ffffffbf ffffffff ffffffff ffdff7ff ffffffff c02d0fd4 00100100 
00200200
GPR24: c031220c 00000001 00000001 00000000 00000000 df849800 ff109000 
df849b80
NIP [c01a10c4] dev_kfree_skb_irq+0x18/0x70
LR [c013b254] gfar_clean_tx_ring+0x70/0x11c
Call Trace:
[c02e7dd0] [c003e978] update_wall_time+0x730/0x744 (unreliable)
[c02e7df0] [c013b254] gfar_clean_tx_ring+0x70/0x11c
[c02e7e10] [c013c07c] gfar_poll+0x44/0x150
[c02e7e30] [c01a064c] net_rx_action+0xa8/0x19c
[c02e7e70] [c00251d4] __do_softirq+0x64/0xc0
[c02e7e90] [c0006384] do_softirq+0x40/0x58
[c02e7ea0] [c00250a8] irq_exit+0x40/0x9c
[c02e7eb0] [c000642c] do_IRQ+0x90/0xac
[c02e7ec0] [c0010ab4] ret_from_except+0x0/0x14
--- Exception: 501 at cpu_idle+0x9c/0xf8
    LR = cpu_idle+0x9c/0xf8
[c02e7f80] [c0009820] cpu_idle+0x58/0xf8 (unreliable)
[c02e7fa0] [c01fb8c8] __got2_end+0x7c/0x90
[c02e7fc0] [c026c794] start_kernel+0x2c0/0x2d4
[c02e7ff0] [00003438] 0x3438
Instruction dump:
7fa00124 80010024 bba10014 38210020 7c0803a6 4e800020 9421ffe0 7c0802a6
7c6b1b78 90010024 380300a0 bfa10014 <7d200028> 3129ffff 7d20012d 40a2fff4
Kernel panic - not syncing: Fatal exception in interrupt

This Patch calls netif_stop_queue before calling stop_gfar.
Signed-off-by: NMarkus Brunner <super.firetwister@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can't put 'mdio' until after we've used it in the
fsl_pq_mdio_bus_name() call.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Noticed by Li Yang.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code that was added to increase headroom was wrong.
It doesn't handle the case where gfar_add_fcb() changes the skb.
Better to do check at start of transmit (outside of lock), where
error handling is better anyway.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Gianfar uses a hardware header FCB for offloading.  However when used
with bridging or IP forwarding, TX skb might not have enough headroom
for the FCB.  Reallocate skb for such cases.
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 4826857f ("gianfar: pass the
proper dev to DMA ops") introduced this build breakage:

  CC      drivers/net/gianfar.o
drivers/net/gianfar.c: In function 'gfar_suspend':
drivers/net/gianfar.c:552: error: 'struct gfar_private' has no member named 'dev'
drivers/net/gianfar.c: In function 'gfar_resume':
drivers/net/gianfar.c:601: error: 'struct gfar_private' has no member named 'dev'
make[2]: *** [drivers/net/gianfar.o] Error 1

Fix this by converting suspend and resume routines to use
gfar_private->ndev.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to be passing the of_platform device struct into the DMA ops as
its the one that has the archdata setup to know which low-level DMA ops we
should be using (not the net_device one).  This isn't an issue until we
expect the archdata to be setup correctly.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes a wrong check on num_txbdfree. It could lead to
num_txbdfree become nagative.  Result was that the gianfar stops
sending data.

Changes from first version :
- removed a space between parens (David Millers comment)
- full email address in signed off line
Signed-off-by: NRini van Zetten <rini@arvoo.nl>
Acked-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ira Snyder found that commit 8c7396ae
"gianfar: Merge Tx and Rx interrupt for scheduling clean up ring" can
cause hangs. It's because there was removed clearing of interrupts in
gfar_schedule_cleanup() (which is called by an interrupt handler) in
case when netif scheduling has been disabled. This patch brings back
this action and a comment.
Reported-by: NIra Snyder <iws@ovro.caltech.edu>
Reported-by: NPeter Korsgaard <jacmet@sunsite.dk>
Bisected-by: NIra Snyder <iws@ovro.caltech.edu>
Tested-by: NPeter Korsgaard <jacmet@sunsite.dk>
Tested-by: NIra Snyder <iws@ovro.caltech.edu>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Stashing is only supported on the 85xx (e500-based) SoCs.  The 83xx and 86xx
chips don't have a proper cache for this.  U-Boot has been updated to add
stashing properties to the device tree nodes of gianfar devices on 85xx.  So
now we modify Linux to keep stashing off unless those properties are there.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The MDIO bus drivers for the UCC and gianfar ethernet controllers are
essentially the same.  There's no reason to duplicate that much code.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SOFT_RESET must be asserted for at least 3 TX clocks in order for it to work
properly.  The syncs in the gfar_write() commands have been hiding this, but
we need to guarantee it.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes following sparse warnings:

  CHECK   gianfar_ethtool.c
gianfar_ethtool.c:610:26: warning: symbol 'gfar_ethtool_ops' was not declared. Should it be static?
  CHECK   gianfar_mii.c
gianfar_mii.c:108:35: warning: cast adds address space to expression (<asn:2>)
gianfar_mii.c:119:35: warning: cast adds address space to expression (<asn:2>)
gianfar_mii.c:128:35: warning: cast adds address space to expression (<asn:2>)
gianfar_mii.c:272:5: warning: cast removes address space of expression
gianfar_mii.c:271:15: warning: cast adds address space to expression (<asn:2>)
gianfar_mii.c:340:11: warning: cast adds address space to expression (<asn:2>)
  CHECK   gianfar_sysfs.c
gianfar_sysfs.c:84:1: warning: symbol 'dev_attr_bd_stash' was not declared. Should it be static?
gianfar_sysfs.c:133:1: warning: symbol 'dev_attr_rx_stash_size' was not declared. Should it be static?
gianfar_sysfs.c:175:1: warning: symbol 'dev_attr_rx_stash_index' was not declared. Should it be static?
gianfar_sysfs.c:213:1: warning: symbol 'dev_attr_fifo_threshold' was not declared. Should it be static?
gianfar_sysfs.c:250:1: warning: symbol 'dev_attr_fifo_starve' was not declared. Should it be static?
gianfar_sysfs.c:287:1: warning: symbol 'dev_attr_fifo_starve_off' was not declared. Should it be static?
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements wakeup management for the gianfar driver.

The driver should set wakeup enable if WOL is enabled, so that
phylib won't power off an attached PHY.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 77ecaf2d ("gianfar: Fix VLAN
HW feature related frame/buffer size calculation") wrongly removed
priv->vlgrp assignment, and now priv->vlgrp is always NULL.

This patch fixes the issue, plus fixes following sparse warning
introduced by the same commit:
gianfar.c:1406:13: warning: context imbalance in 'gfar_vlan_rx_register' - wrong count at exit

gfar_vlan_rx_register() checks for "if (old_grp == grp)" and tries
to return w/o dropping the lock.

According to net/8021q/vlan.c VLAN core issues rx_register() callback:
1. In register_vlan_dev() only on a newly created group;
2. In unregister_vlan_dev() only if the group becomes empty.

Thus the check in the gianfar driver isn't needed.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Following the removal of the unused struct net_device * parameter from
the NAPI functions named *netif_rx_* in commit 908a7a16, they are
exactly equivalent to the corresponding *napi_* functions and are
therefore redundant.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes following bug:

BUG: soft lockup - CPU#0 stuck for 61s! [S03mountvirtfs-:922]
Modules linked in:
NIP: c006505c LR: c00675f0 CTR: c0020438
REGS: c7a1db90 TRAP: 0901   Not tainted  (2.6.28-rc8-01311-g8c7396ae)
MSR: 00009032 <EE,ME,IR,DR>  CR: 28248442  XER: 20000000
TASK = c7a288a0[922] 'S03mountvirtfs-' THREAD: c7a1c000
GPR00: 00009032 c7a1dc40 c7a288a0 00000024 c79a1840 00000000 00000300 00000020
GPR08: c035f97c 00000000 00004008 c04d5210 00000000
NIP [c006505c] handle_IRQ_event+0x34/0xb0
LR [c00675f0] handle_level_irq+0xa8/0x144
Call Trace:
[c7a1dc40] [c00204d8] ipic_mask_irq+0xa0/0xb4 (unreliable)
[c7a1dc60] [c00675f0] handle_level_irq+0xa8/0x144
[c7a1dc80] [c00067f8] do_IRQ+0x78/0x108
[c7a1dc90] [c0014d7c] ret_from_except+0x0/0x14
--- Exception: 501 at gfar_schedule_cleanup+0x54/0x7c
    LR = gfar_transmit+0x14/0x28
[c7a1dd50] [c0352a3c] _spin_unlock_irqrestore+0x18/0x30 (unreliable)
[c7a1dd60] [c01f49a8] gfar_transmit+0x14/0x28
[c7a1dd70] [c0065084] handle_IRQ_event+0x5c/0xb0
[c7a1dd90] [c00675f0] handle_level_irq+0xa8/0x144
[c7a1ddb0] [c00067f8] do_IRQ+0x78/0x108
[c7a1ddc0] [c0014d7c] ret_from_except+0x0/0x14
--- Exception: 501 at up_read+0x10/0x48
    LR = do_page_fault+0x2b0/0x3e0
[c7a1de80] [c7a177e8] 0xc7a177e8 (unreliable)
[c7a1de90] [c0017964] do_page_fault+0x2b0/0x3e0
[c7a1df40] [c0014b14] handle_page_fault+0xc/0x80
--- Exception: 301 at 0xfe98b7c
    LR = 0xfe989c0
Instruction dump:
7c0802a6 bf810010 7c9f2378 7c7c1b78 90010024 80040004 70090020 40820010
7c0000a6 60008000 7c000124 3bc00000 <3ba00000> 48000010 83ff0014 2f9f0000


The bug introduced by commit 8c7396ae
("gianfar: Merge Tx and Rx interrupt for scheduling clean up ring").

The commit merged TX and RX interrupt code into a single routine that
schedules NAPI, but no locks were introduced. This causes irq races, so
when irqs are enabled and netif_rx_schedule_prep() returns 0, nobody
disable the interrupts again. This leads to interrupt storm and finally
to the lockup.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>