Move the mapping of the head BD before the mapping of fragments.
The TOE (h/w offload) decision logic block can be also moved up
(as the TOE flag belongs to the head BD), resulting in more
localized code (TOE logic vs BD mapping code blocks).
Note that, for this h/w, the R (status) bit for the head BD of a S/G
frame needs to be written last for a reliable transmission.
For the fragmented skb case, a local variable is used to temporarily
store the status info of the first BD, replacing a BD status read.
A merge of 2 "if(do_tstamp)" blocks was also possible.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Not all devices attached to an MDIO bus are phys. So add an
mdio_device structure to represent the generic parts of an mdio
device, and place this structure into the phy_device.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After commit 15bf176d ("gianfar: Don't enable the Filer w/o the
Parser"), 'TSEC' model controllers (for example as seen on MPC8541E)
always have 8 bytes stripped from the front of received frames.
Only 'eTSEC' gianfar controllers have the RX Filer capability (amongst
other enhancements). Previously this was treated as always enabled
for both 'TSEC' and 'eTSEC' controllers.
In commit 15bf176d ("gianfar: Don't enable the Filer w/o the Parser")
a subtle change was made to the setting of 'uses_rxfcb' to effectively
always set it (since 'rx_filer_enable' was always true). This had the
side-effect of always stripping 8 bytes from the front of received frames
on 'TSEC' type controllers.

We now only enable the RX Filer capability on controller types that
support it, thereby avoiding the issue for 'TSEC' type controllers.
Reviewed-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: NMark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: NHamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This driver can be built on arm64 but relies on NO_IRQ to check the return
value of irq_of_parse_and_map() which fails to build on arm64 because the
architecture does not provide a NO_IRQ. Fix this to correctly check the
return value of irq_of_parse_and_map().

Even on ARM systems where the driver was previously used the check was
broken since on ARM NO_IRQ is -1 but irq_of_parse_and_map() returns 0 on
error.
Signed-off-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

use of_property_read_bool() for testing bool property
Signed-off-by: NSaurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

netif_tx_napi_add() is a variant of netif_napi_add()

It should be used by drivers that use a napi structure
to exclusively poll TX.

We do not want to add this kind of napi in napi_hash[] in following
patches, adding generic busy polling to all NAPI drivers.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Increased TX_TIMEOUT to 5HZ to accommodate worst case situation
for traffic and CPU intensive use cases
Signed-off-by: NPriyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: NAbhimanyu <abhimanyu@freescale.com>
Acked-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Rx BSY error interrupt indicates that a frame was
received and discarded due to lack of buffers, so it's
a rx ring overflow condition and has nothing to do with
with bad rx packets.  Use the right counter.

BSY conditions happen when the SoC is under performance
stress.  Doing *more* work in stress situations by trying
to schedule NAPI is not a good idea as the stressed system
becomes still more stressed.  The Rx interrupt is already
at work making sure the NAPI is scheduled.
So calling gfar_receive() here does not help.  This issue
was present since day 1.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Under one unusual circumstance it's possible to wrongly set
FILREN without enabling PRSDEP as well in the RCTRL register,
against the hardware specifications.  With the default config
this does not happen because the default Rx offloads (Rx csum
and Rx VLAN) properly enable PRSDEP.  But if anyone disables
all these offloads (via ethtool), we get a wrong configuration
were the Rx flow classification and hashing, and other Filer
based features (e.g. wake-on-filer interrupt) won't work.
This patch fixes the issue.
Also, account for Rx FCB insertion which happens every time
PRSDEP is set.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This enables eTSEC's filer (Rx parser) and the FGPI Rx
interrupt (Filer General Purpose Interrupt) as a wakeup
source event.

Upon entering suspend state, the eTSEC filer is given
a rule to match incoming L2 unicast packets.  A packet
matching the rule will be enqueued in the Rx ring and
a FGPI Rx interrupt will be asserted by the filer to
wakeup the system.  Other packet types will be dropped.
On resume the filer table is restored to the content
before entering suspend state.
The set of rules from gfar_filer_config_wol() could be
extended to implement other WoL capabilities as well.

The "fsl,wake-on-filer" DT binding enables this capability
on certain platforms that feature the necessary power
management infrastructure, targeting mainly printing and
imaging applications.
(refer to Power Management section of the SoC Ref Man)

Cc: Li Yang <leoli@freescale.com>
Cc: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a phy_device_remove() function to complement phy_device_register(),
which undoes the effects of phy_device_register() by removing the phy
device from visibility, but not freeing it.

This allows these details to be moved out of the mdio bus code into
the phy code where this action belongs.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_phy_find_device() increments the phy struct device refcount, which
we need to properly balance.  Add code to network drivers using this
function to ensure that the struct device refcount is correctly
balanced.

For xgene, looking back in the history, we should be able to use
of_phy_connect() with a zero flags argument for the DT case as this is
how the driver used to operate prior to de7b5b3d ("net: eth: xgene:
change APM X-Gene SoC platform ethernet to support ACPI").

This leaves the Cavium Thunder BGX unfixed; fixing this driver is a
complicated task, one which the maintainers need to be involved with.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The device is set as wakeup capable using proper wakeup API but the
driver misuses IRQF_NO_SUSPEND to set the interrupt as wakeup source
which is incorrect.

This patch removes the use of IRQF_NO_SUSPEND flags replacing it with
enable_irq_wake instead.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Claudiu Manoil <claudiu.manoil@freescale.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: netdev@vger.kernel.org
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are some MAC registers that need to be kept in sync
with the link state parameters, see adjust_link().
However, after a MAC soft reset default values for
these registers are assumed.  In some cases (excepting
if down/ if up for example) adjust_link() does not see
that these values were reset to default because the
priv->old* link parameters were left unchanged.
So, reset the priv->old* link params as well during a
MAC reset to let adjust_link() restore the MAC link
settings to the actual link state values.

Fixes following case, for example:
Setting link to 100M, changing MTU (implies MAC reset),
link state remains unchanged to 100M but MAC registers
were reset to default (1G) breaking the connectivity w/
the PHY.  Closing and re-opening the interface would
restore the MAC link parameters to the correct values.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The wol_en flag is 0 by default anyway, and we have the
following inconsistency: a MAGIC packet wol capable eth
interface is registered as a wake-up source but unable
to wake-up the system as wol_en is 0 (wake-on flag set to 'd').
Calling set_wakeup_enable() at netdev open is just redundant
because wol_en is 0 by default.
Let only ethtool call set_wakeup_enable() for now.

The bflock is obviously obsoleted, its utility has been corroded
over time.  The bitfield flags used today in gianfar are accessed
only on the init/ config path, with no real possibility of
concurrency - nothing that would justify smth. like bflock.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we disable NAPI in the first place we can mask the device's
interrupts (and halt it) without fearing that imask may be
concurrently accessed from interrupt context, so there's
no need to do local_irq_save() around gfar_halt_nodisable().
lock_rx_qs()/unlock_tx_qs() are just obsoleted and potentially
buggy routines.  The txlock is currently used in the driver only
to manage TX congestion, it has nothing to do with halting the
device.  With these changes, the TX processing is stopped before
gfar_halt().

Compact gfar_halt() is used instead of gfar_halt_nodisable(),
as it disables Rx/TX DMA h/w blocks and the Rx/TX h/w queues.
gfar_start() re-enables all these blocks on resume.  Enabling
the magic-packet mode remains the same, note that the RX block
is re-enabled just before entering sleep mode.

Add IRQF_NO_SUSPEND flag for the error interrupt line, to signal
that the interrupt line must remain active during sleep in order
to wake the system by magic packet (MAG) reception interrupt.
(On some systems the MAG interrupt did trigger w/o this flag
as well, but on others it didn't.)

Without these fixes, when suspended during fair Tx traffic the
interface occasionally failed to be woken up by magic packet.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CC      drivers/net/ethernet/freescale/gianfar.o
drivers/net/ethernet/freescale/gianfar.c:568:13: warning: 'lock_tx_qs'
defined but not used [-Wunused-function]
 static void lock_tx_qs(struct gfar_private *priv)
             ^
drivers/net/ethernet/freescale/gianfar.c:576:13: warning: 'unlock_tx_qs'
defined but not used [-Wunused-function]
 static void unlock_tx_qs(struct gfar_private *priv)
             ^
Reported-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of defconfig consolidation using fragments, we'd like to be
able to have the same drivers enabled on 32-bit and 64-bit.  Gianfar
happens to only exist on 32-bit systems, and when building the
resulting 64-bit kernel warnings were produced.

A couple of the warnings are trivial, but the rfbptr code has deeper
issues.  It uses the virtual address as the DMA address, which again,
happens to work in the environments where this driver is currently
used, but is not the right thing to do.

Fixes: 45b679c9 ("gianfar: Implement PAUSE frame generation
support")
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The eTSEC h/w is capable of scatter/gather on the receive side
too if MAXFRM > MRBLR, when the allowed maximum Rx frame size
is set to be greater than the maximum Rx buffer size (MRBLR).
It's about time the driver makes use of this h/w capability,
by supporting fixed buffer sizes and Rx S/G.

The buffer size given to eTSEC for reception is fixed to
1536B (must be multiple of 64), which is the same default
buffer size as before, used to accommodate standard MTU
(1500B) size frames.  As before, eTSEC can receive frames of
up to 9600B.  Individual Rx buffers are mapped to page halves
(page size for eTSEC systems is 4KB).  The skb is built around
the first buffer of a frame (using build_skb()).  In case the
frame spans multiple buffers, the trailing buffers are added
as Rx fragments to the skb.  The last buffer in frame is marked
by the L status flag.  A mechanism is in place to reuse the pages
owned by the driver (for Rx) for subsequent receptions.

Supporting fixed size buffers allows the implementation of Rx S/G,
which in turn removes the memory pressure issues the driver had
before when MTU was set for jumbo frame reception.
Also, in most cases, the Rx path becomes faster due to Rx page
reusal, since the overhead of allocating new rx buffers is removed
from the fast path.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use "ndev" instead of "dev", as the rx queue back pointer
to a net_device struct, to avoid name clashing with a
"struct device" reference.  This prepares the addition of a
"struct device" back pointer to the rx queue structure.

Remove duplicated rxq registration in the process.
Move napi_gro_receive() outside gfar_process_frame().
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are several (long standing) problems about how the status
field of the rx buffer descriptor (rxbd) is currently handled on
the error path:
- too many unnecessary 16bit reads of the two halves of the rxbd
status field (32bit), also resulting in overuse of endianness
convesion macros;
- "bdp->status = RXBD_LARGE" makes no sense, since the "large"
flag is read only (only eTSEC can write it), and trying to clear
the other status bits is also error prone in this context
(most of the rx status bits are read only anyway).

This is fixed with a single 32bit read of the "status" field,
and then the appropriate 16bit shifting is applied to access
the various status bits or the rx frame length. Also corrected
the use of the RXBD_LARGE flag.

Additional fix:
"rx_over_errors" stat is incremented instead of "rx_crc_errors"
in case of RXBD_OVERRUN occurrence.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a more common consumer/ producer index design to improve
rx buffer allocation.  Instead of allocating a single new buffer
(skb) on each iteration, bundle the allocation of several rx
buffers at a time.  This also opens the path for further memory
optimizations.

Remove useless check of rxq->rfbptr, since this patch touches
rx pause frame handling code as well.  rxq->rfbptr is always
initialized as part of Rx BD ring init.
Remove redundant (and misleading) 'amount_pull' parameter.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use device flag IFF_LIVE_ADDR_CHANGE to signal that
the device supports changing the hardware address when
the device is running.
This allows eth_mac_addr() to change the mac address
also when the network device's interface is open.
This capability is required by certain applications,
like bonding mode 6 (Adaptive Load Balancing).
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Handle TxFIFO underrun exceptions outside the fast path.
A controller reset is more reliable in this exceptional
case, as opposed to re-enabling on-the-fly the Tx DMA.

As the controller reset is handled outside the fast path
by the reset_gfar() workqueue handler, the locking
scheme on the Tx path is significantly simplified.
Because the Tx processing (xmit queues and tx napi) is
disabled during controller reset, tstat access from xmit
does not require locking.  So the scope of the txlock on
the processing path is now reduced to num_txbdfree, which
is shared only between process context (xmit) and softirq
(clean_tx_ring).  As a result, the txlock must not guard
against interrupt context, and the spin_lock_irqsave()
from xmit can be replaced by spin_lock_bh().  Likewise,
the locking has been downgraded for clean_tx_ring().
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use of_property_read*() to get arch endian consistent
property values. Do some refactoring in the process.
Signed-off-by: NJingchang Lu <jingchang.lu@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use conversion macros to correctly access the BE
fields of the Rx and Tx Frame Control Block on LE CPUs.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use conversion macros to correctly access the BE
fields of the Rx and Tx Buffer Descriptors on LE CPUs.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

eTSEC of-nodes may have children which are not queue-group nodes. For
example new-style fixed-phy declarations. These where incorrectly
assumed to be additional queue-groups.

Change the search to filter out any nodes which are not queue-groups,
or have been disabled.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 6ce29b0e ("gianfar: Avoid unnecessary reg accesses in adjust_link()")
eliminates unnecessary calls to adjust_link for phy devices which don't support
interrupts and need polling. As part of that work, the 'new_state' local flag,
which was used to reduce logging noise on the console, was eliminated.

Unfortunately, that means that a 'Link is Down' log message will now be
issued continuously if a link is configured as UP, the link state is down,
and the associated phy requires polling. This occurs because priv->oldduplex
is -1 in this case, which always differs from phydev->duplex. In addition,
phydev->speed may also differ from priv->oldspeed.  gfar_update_link_state()
is therefore called each time a phy is polled, even if the link state did not
change.

Cc: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit cd1e6504 ("of/device: Don't register disabled
devices"), the disabled device will not be registered at all. So we
don't need to do the check again in the platform device driver.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The same macros are used for rx as well. So rename it.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the following spare warning:
drivers/net/ethernet/freescale/gianfar.c:3521:60: warning: incorrect type in argument 1 (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:3521:60:    expected unsigned int [noderef] <asn:2>*addr
drivers/net/ethernet/freescale/gianfar.c:3521:60:    got unsigned int [usertype] *rfbptr
drivers/net/ethernet/freescale/gianfar.c:205:16: warning: incorrect type in assignment (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:205:16:    expected unsigned int [usertype] *rfbptr
drivers/net/ethernet/freescale/gianfar.c:205:16:    got unsigned int [noderef] <asn:2>*<noident>
drivers/net/ethernet/freescale/gianfar.c:2918:44: warning: incorrect type in argument 1 (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:2918:44:    expected unsigned int [noderef] <asn:2>*addr
drivers/net/ethernet/freescale/gianfar.c:2918:44:    got unsigned int [usertype] *rfbptr
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to use dma_mapping_error() to check the dma address returned
by dma_map_single/page(). Otherwise we would get warning like this:
  WARNING: at lib/dma-debug.c:1140
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.0-rc2-next-20141029 #196
  task: c0834300 ti: effe6000 task.ti: c0874000
  NIP: c02b2c98 LR: c02b2c98 CTR: c030abc4
  REGS: effe7d70 TRAP: 0700   Not tainted  (3.18.0-rc2-next-20141029)
  MSR: 00021000 <CE,ME>  CR: 22044022  XER: 20000000

  GPR00: c02b2c98 effe7e20 c0834300 00000098 00021000 00000000 c030b898 00000003
  GPR08: 00000001 00000000 00000001 749eec9d 22044022 1001abe0 00000020 ef278678
  GPR16: ef278670 ef278668 ef278660 070a8040 c087f99c c08cdc60 00029000 c0840d44
  GPR24: c08be6e8 c0840000 effe7e78 ef041340 00000600 ef114e10 00000000 c08be6e0
  NIP [c02b2c98] check_unmap+0x51c/0x9e4
  LR [c02b2c98] check_unmap+0x51c/0x9e4
  Call Trace:
  [effe7e20] [c02b2c98] check_unmap+0x51c/0x9e4 (unreliable)
  [effe7e70] [c02b31d8] debug_dma_unmap_page+0x78/0x8c
  [effe7ed0] [c03d1640] gfar_clean_rx_ring+0x208/0x488
  [effe7f40] [c03d1a9c] gfar_poll_rx_sq+0x3c/0xa8
  [effe7f60] [c04f8714] net_rx_action+0xc0/0x178
  [effe7f90] [c00435a0] __do_softirq+0x100/0x1fc
  [effe7fe0] [c0043958] irq_exit+0xa4/0xc8
  [effe7ff0] [c000d14c] call_do_irq+0x24/0x3c
  [c0875e90] [c00048a0] do_IRQ+0x8c/0xf8
  [c0875eb0] [c000ed10] ret_from_except+0x0/0x18

For TX, we need to unmap the pages which has already been mapped and
free the skb before return.

For RX, move the dma mapping and error check to gfar_new_skb(). We
would reuse the original skb in the rx ring when either allocating
skb failure or dma mapping error.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Reviewed-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The hardware can automatically generate pause frames when the number
of free buffers drops under a certain threshold, but in order to do this,
the address of the last free buffer needs to be written to a specific
register for each RX queue.

This has to be done in 'gfar_clean_rx_ring' which is called for each
RX queue. In order not to impact performance, by adding a register write
for each incoming packet, this operation is done only when the PAUSE frame
transmission is enabled.

Whenever the link is readjusted, this capability is turned on or off.
Signed-off-by: NMatei Pavaluca <matei.pavaluca@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Local flow control options needed in order to resolve the negotiation
are incorrectly calculated.

Previously 'mii_advertise_flowctrl' was called to determine the local advertising
options, but these were determined based on FLOW_CTRL_RX/TX flags which are
never set through ethtool.
The patch simply translates from ethtool flow options to mii flow options.
Signed-off-by: NPavaluca Matei <matei.pavaluca@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The phy device supports 802.3x flow control, but the specific flags are not set
in the phy initialisation code. Flow control flags need to be added to the
supported capabilities of the phydev by the driver.

This is needed in order for ethtool to work ('ethtool -A' code checks for these
flags)
Signed-off-by: NPavaluca Matei <matei.pavaluca@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

For each Rx frame the eTSEC writes its FCS (Frame Check Sequence)
to the Rx buffer.

The eTSEC h/w manual states in the "Receive Buffer Descriptor Field
Descriptions" table:
"Data length is the number of octets written by the eTSEC into this BD's
data buffer if L is cleared (the value is equal to MRBLR), or, if L is
set, the length of the frame including *CRC*, FCB (if RCTRL[PRSDEP > 00),
preamble (if MACCFG2[PreAmRxEn]=1), time stamp (if RCTRL[TS] = 1) and
any padding (RCTRL[PAL])."

Though the FCS bytes are removed by the driver before passing the skb
to the net stack, the Rx buffer size computation does not currently
take into account the FCS bytes (4 bytes).
Because the Rx buffer size is multiple of 512 bytes, leaving out the
FCS is not a problem for the default MTU of 1500, as the Rx buffer size
is 1536 in this case.  However, for custom MTUs, where the difference
between the MTU size and the Rx buffer size is less, this can be a
problem as the computed Rx buffer size won't be enough to accomodate
the FCS for a received frame that is big enough (close to MTU size).
In such case the received frame is considered to be incomplete (L flag
not set in the RxBD status) and silently dropped.

Note that the driver does not currently support S/G on Rx, so it has to
compute its Rx buffer size based on the MTU of the device.
Reported-by: NKristian Otnes <kotnes@cisco.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>