We currently parse the SFP EEPROM to a bitmap of ethtool link modes,
and then attempt to convert the link modes to a PHY interface mode.
While this works at present, there are cases where this is sub-optimal.
For example, where a module can operate with several different PHY
interface modes.
To start addressing this, arrange for the SFP EEPROM parsing to also
provide a bitmap of the possible PHY interface modes.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a quirk for the HALNy HL-GSFP module, which appears to have an
inverted RX_LOS signal, and maybe uses TX_FAULT as a serial port
transmit pin. Rather than use these hardware signals, switch to
using software polling for these status signals.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move this module over to the new fixup mechanism.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a new fixup mechanism to the SFP quirks, and use it for this
module.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We need to handle more quirks than just those which affect the link
modes of the module. Move the quirk lookup into sfp.c, and pass the
quirk to sfp-bus.c
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Re-implement the decision making for soft state polling. Instead of
generating the soft state mask in sfp_soft_start_poll() by looking at
which GPIOs are available, record their availability in
sfp_sm_mod_probe() in sfp->state_hw_mask.
This will then allow us to clear bits in sfp->state_hw_mask in module
specific quirks when the hardware signals should not be used, thereby
allowing us to switch to using the software state polling.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c
9c5de246c1 ("net: sparx5: mdb add/del handle non-sparx5 devices")
fbb89d02e3 ("net: sparx5: Allow mdb entries to both CPU and ports")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sfp_probe() allocates a memory chunk from sfp with sfp_alloc(). When
devm_add_action() fails, sfp is not freed, which leads to a memory leak.
We should use devm_add_action_or_reset() instead of devm_add_action().
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20220629075550.2152003-1-niejianglei2021@163.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Instead of open-coding the bad characters replacement in the hwmon name,
use the new hwmon_sanitize_name().
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As noted elsewhere, various GPON SFP modules exhibit non-standard
TX-fault behaviour. In the tested case, the Huawei MA5671A, when used
in combination with a Marvell mv88e6085 switch, was found to
persistently assert TX-fault, resulting in the module being disabled.
This patch adds a quirk to ignore the SFP_F_TX_FAULT state, allowing the
module to function.
Change from v1: removal of erroneous return statment (Andrew Lunn)
Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220502223315.1973376-1-mnhagan88@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Convert sfp to use %pe for printing error codes, which can print them
as errno symbols rather than numbers.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/E1nOyEN-00BuuE-OB@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 7cfa9c92d0 ("net: sfp: avoid power switch on address-change
modules") unintetionally changed the semantics for high power modules
without the digital diagnostics monitoring. We repeatedly attempt to
read the power status from the non-existing 0xa2 address in a futile
hope this failure is temporary:
[ 8.856051] sfp sfp-eth3: module NTT 0000000000000000 rev 0000 sn 0000000000000000 dc 160408
[ 8.865843] mvpp2 f4000000.ethernet eth3: switched to inband/1000base-x link mode
[ 8.873469] sfp sfp-eth3: Failed to read EEPROM: -5
[ 8.983251] sfp sfp-eth3: Failed to read EEPROM: -5
[ 9.103250] sfp sfp-eth3: Failed to read EEPROM: -5
We previosuly assumed such modules were powered up in the correct mode,
continuing without further configuration as long as the required power
class was supported by the host.
Restore this behaviour, while preserving the intent of subsequent
patches to avoid the "Address Change Sequence not supported" warning
if we are not going to be accessing the DDM address.
Fixes: 7cfa9c92d0 ("net: sfp: avoid power switch on address-change modules")
Reported-by: 照山周一郎 <teruyama@springboard-inc.jp>
Tested-by: 照山周一郎 <teruyama@springboard-inc.jp>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The string should be "tx_disable" to match the state enum.
Fixes: 4005a7cb4f ("net: phy: sftp: print debug message with text, not numbers")
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are some repeated words in some comments, they should be deleted.
Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The new netlink API for reading SFP data requires a new op to be
implemented. The idea of the new netlink SFP code is that userspace is
responsible to parsing the EEPROM data and requesting pages, rather
than have the kernel decide what pages are interesting and returning
them. This allows greater flexibility for newer formats.
Currently the generic SFP code only supports simple SFPs. Allow i2c
address 0x50 and 0x51 to be accessed with page and bank must always be
0. This interface will later be extended when for example QSFP support
is added.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vladyslav Tarasiuk <vladyslavt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Ubiquiti U-Fiber Instant SFP GPON module has nonsensical information
stored in its EEPROM. It claims to support all transceiver types including
10G Ethernet. Clear all claimed modes and set only 1000baseX_Full, which is
the only one supported.
This module has also phys_id set to SFF, and the SFP subsystem currently
does not allow to use SFP modules detected as SFFs. Add exception for this
module so it can be detected as supported.
This change finally allows to detect and use SFP GPON module Ubiquiti
U-Fiber Instant on Linux system.
EEPROM content of this SFP module is (where XX is serial number):
00: 02 04 0b ff ff ff ff ff ff ff ff 03 0c 00 14 c8 ???........??.??
10: 00 00 00 00 55 42 4e 54 20 20 20 20 20 20 20 20 ....UBNT
20: 20 20 20 20 00 18 e8 29 55 46 2d 49 4e 53 54 41 .??)UF-INSTA
30: 4e 54 20 20 20 20 20 20 34 20 20 20 05 1e 00 36 NT 4 ??.6
40: 00 06 00 00 55 42 4e 54 XX XX XX XX XX XX XX XX .?..UBNTXXXXXXXX
50: 20 20 20 20 31 34 30 31 32 33 20 20 60 80 02 41 140123 `??A
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The workaround for VSOL V2801F brand based GPON SFP modules added in commit
0d035bed2a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0
workaround") works only for IDs added explicitly to the list. Since there
are rebranded modules where OEM vendors put different strings into the
vendor name field, we cannot base workaround on IDs only.
Moreover the issue which the above mentioned commit tried to work around is
generic not only to VSOL based modules, but rather to all GPON modules
based on Realtek RTL8672 and RTL9601C chips.
These include at least the following GPON modules:
* V-SOL V2801F
* C-Data FD511GX-RM0
* OPTON GP801R
* BAUDCOM BD-1234-SFM
* CPGOS03-0490 v2.0
* Ubiquiti U-Fiber Instant
* EXOT EGS1
These Realtek chips have broken EEPROM emulator which for N-byte read
operation returns just the first byte of EEPROM data, followed by N-1
zeros.
Introduce a new function, sfp_id_needs_byte_io(), which detects SFP modules
with broken EEPROM emulator based on N-1 zeros and switch to 1 byte EEPROM
reading operation.
Function sfp_i2c_read() now always uses single byte reading when it is
required and when function sfp_hwmon_probe() detects single byte access,
it disables registration of hwmon device, because in this case we cannot
reliably and atomically read 2 bytes as is required by the standard for
retrieving values from diagnostic area.
(These Realtek chips are broken in a way that violates SFP standards for
diagnostic interface. Kernel in this case simply cannot do anything less
of skipping registration of the hwmon interface.)
This patch fixes reading of EEPROM content from SFP modules based on
Realtek RTL8672 and RTL9601C chips. Diagnostic interface of EEPROM stays
broken and cannot be fixed.
Fixes: 0d035bed2a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround")
Co-developed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add debugfs support to SFP so that the internal state of the SFP state
machines and hardware signal state can be viewed from userspace, rather
than having to compile a debug kernel to view state transitions in the
kernel log. The 'state' output looks like:
Module state: empty
Module probe attempts: 0 0
Device state: up
Main state: down
Fault recovery remaining retries: 5
PHY probe remaining retries: 12
moddef0: 0
rx_los: 1
tx_fault: 1
tx_disable: 1
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1kyYRe-0004kN-3F@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The SFP MSA defines two option bits in byte 65 to indicate how the
Rx_LOS signal on SFP pin 8 behaves:
bit 2 - Loss of Signal implemented, signal inverted from standard
definition in SFP MSA (often called "Signal Detect").
bit 1 - Loss of Signal implemented, signal as defined in SFP MSA
(often called "Rx_LOS").
Clearly, setting both bits results in a meaningless situation: it would
mean that LOS is implemented in both the normal sense (1 = signal loss)
and inverted sense (0 = signal loss).
Unfortunately, there are modules out there which set both bits, which
will be initially interpret as "inverted" sense, and then, if the LOS
signal changes state, we will toggle between LINK_UP and WAIT_LOS
states.
Change our LOS handling to give well defined behaviour: only interpret
these bits as meaningful if exactly one is set, otherwise treat it as
if LOS is not implemented.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/E1kyYQa-0004iR-CU@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a workaround for the detection of VSOL V2801F / CarlitoxxPro
CPGOS03-0490 v2.0 GPON module which CarlitoxxPro states needs single
byte I2C reads to the EEPROM.
Pali Rohár reports that he also has a CarlitoxxPro-based V2801F module,
which reports a manufacturer of "OEM". This manufacturer can't be
matched as it appears in many different modules, so also match the part
number too.
Reported-by: Thomas Schreiber <tschreibe@gmail.com>
Reported-by: Pali Rohár <pali@kernel.org>
Tested-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
gpiod_to_irq() never return 0, but returns negative in
case of error, check it and set gpio_irq to 0.
Fixes: 7397005545 ("sfp: add SFP module support")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201031031053.25264-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.
Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In preparation for moving all MDIO drivers into drivers/net/mdio, move
the mdio-i2c header file into include/linux/mdio so it can be used by
both the MDIO driver and the SFP code which instantiates I2C MDIO
busses.
v2:
Add include/linux/mdio
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some Cotsworks SFF have invalid data in the first few bytes of the
module EEPROM. This results in these modules not being detected as
valid modules.
Address this by poking the correct EEPROM values into the module
EEPROM when the model/PN match and the existing module EEPROM contents
are not correct.
Signed-off-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Dynamically generate a unique GPIO interrupt name, based on the
device name and the GPIO name. For example:
103: 0 sx1503q 12 Edge sff2-los
104: 0 sx1503q 13 Edge sff2-tx-fault
The sffX indicates the SFP the los and tx-fault are associated with.
v3:
- reverse Christmas tree new variable
- fix spaces vs tabs
v2:
- added net-next to PATCH part of subject line
- switched to devm_kasprintf()
Signed-off-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Report a rate-limited error if we fail to read the SFP soft status,
and preserve the current status in that case. This avoids I2C bus
errors from triggering a link flap.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some 1000BASE-T PHY modules take a while for the PHY to wake up.
Retry the probe a number of times before deciding that the module has
no PHY.
Tested with:
Sourcephotonics SPGBTXCNFC - PHY takes less than 50ms to respond.
Champion One 1000SFPT - PHY takes about 200ms to respond.
Mikrotik S-RJ01 - no PHY
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename sm_retries as sm_fault_retries, as this is what this member is
tracking.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some SFP+ modules have a Clause 45 PHY onboard, which is accessible via
the normal I2C address. Detect 10G BASE-T PHYs which may have an
accessible PHY and probe for it.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move phy_start() and phy_stop() into the module_start and module_stop
notifications in phylink, rather than having them in the SFP code.
This gives phylink responsibility for controlling the PHY, rather
than having SFP start and stop the PHY state machine.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
When dealing with some copper modules, we can't positively know the
module capabilities are until we have probed the PHY. Without the full
capabilities, we may end up failing a module that we could otherwise
drive with a restricted set of capabilities.
An example of this would be a module with a NBASE-T PHY plugged into
a host that supports phy interface modes 2500BASE-X and SGMII. The
PHY supports 10GBASE-R, 5000BASE-X, 2500BASE-X, SGMII interface modes,
which means a subset of the capabilities are compatible with the host.
However, reading the module EEPROM leads us to believe that the module
only supports ethtool link mode 10GBASE-T, which is incompatible with
the host - and thus results in the module being rejected.
This patch adds an extra notification which are triggered after the
SFP module's PHY probe, and a corresponding notification just before
the PHY is removed.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
SFF-8024 is used to define various constants re-used in several SFF
SFP-related specifications. Split these constants from the enum, and
rename them to indicate that they're defined by SFF-8024.
Add and use updated SFF-8024 extended compliance code definitions for
10GBASE-T, 5GBASE-T and 2.5GBASE-T modules.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 100BASE-FX and 100BASE-LX support assumes a PHY is present; this
is probably an incorrect assumption. In any case, sfp_parse_support()
will fail such a module. Let's stop pretending we support these
modules.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Nokia GPON module can hold tx-fault active while it is initialising
which can take up to 60s. Avoid this causing the module to be declared
faulty after the SFP MSA defined non-cooled module timeout.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The referenced commit below allowed more than one hwmon device to be
created per SFP, which is definitely not what we want. Avoid this by
only creating the hwmon device just as we transition to WAITDEV state.
Fixes: 139d3a212a ("net: sfp: allow modules with slow diagnostics to probe")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
When unbinding, we don't correctly tear down the module state, leaving
(for example) the hwmon registration behind. Ensure everything is
properly removed by sending a remove event at unbind.
Fixes: 6b0da5c9c1 ("net: sfp: track upstream's attachment state in state machine")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for the soft status and control register, which allows
TX_FAULT and RX_LOS to be monitored and TX_DISABLE to be set. We
make use of this when the board does not support GPIOs for these
signals.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a spelling mistake in a dev_warn message. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a module is inserted, we attempt to read read the ID from address
0x50. Once we are able to read the ID, we immediately attempt to
initialise the hwmon support by reading from address 0x51. If this
fails, then we fall into error state, and assume that the module is
not usable.
Modules such as the ALCATELLUCENT 3FE46541AA use a real EEPROM for
I2C address 0x50, which responds immediately. However, address 0x51
is an emulated, which only becomes available once the on-board firmware
has booted. This prompts us to fall into the error state.
Since the module may be usable without diagnostics, arrange for the
hwmon probe independent of the rest of the SFP itself, retrying every
5s for up to about 60s for the monitoring to become available, and
print an error message if it doesn't become available.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some GPON modules (e.g. Huawei MA5671A) take a significant amount of
time to start responding on the I2C bus, contary to the SFF
specifications.
Work around this by implementing a two-level timeout strategy, where
we initially quickly retry for the module, and then use a slower retry
after we exceed a maximum number of quick attempts.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the module insertion reporting out of the probe handling, but
after we have detected that the upstream has attached (since that is
whom we are reporting insertion to.)
Only report module removal if we had previously reported a module
insertion.
This gives cleaner semantics, and means we can probe the module before
we have an upstream attached.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Switch the power mode switching from the probe, so that we don't
repeatedly re-probe the SFP device if there is a problem accessing
the registers at I2C address 0x51.
In splitting this out, we can also fix a bug where we leave the module
in high-power mode when the upstream device is detached but the module
is still inserted.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Track the upstream's attachment state in the state machine rather than
maintaining a boolean, which ensures that we have a strict order of
ATTACH followed by an UP event - we can never believe that a newly
attached upstream will be anything but down.
Rearrange the order of state machines so we run the module state
machine after the upstream device's state machine, so the module state
machine can check the current state of the device and take action to
e.g. reset back to empty state when the upstream is detached.
This is to allow the module detection to run independently of the
network device becoming available.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
TX_FAULT should be deasserted to indicate that the module has completed
its initialisation. This may include the on-board PHY, so wait until
the module has deasserted TX_FAULT before probing the PHY.
This means that we need an extra state to handle a TX_FAULT that
remains set for longer than t_init, since using the existing handling
state would bypass the PHY probe.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the next state to sfp_sm_fault() so that it can branch to other
states. This will be necessary to improve the initialisation path.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
