In order to stop the RX path accessing the RX ring while it's being
stopped or resized, we clear the interrupt mask (EESIPR) and then call
free_irq() or synchronise_irq().  This is insufficient because the
interrupt handler or NAPI poller may set EESIPR again after we clear
it.  Also, in sh_eth_set_ringparam() we currently don't disable NAPI
polling at all.

I could easily trigger a crash by running the loop:

   while ethtool -G eth0 rx 128 && ethtool -G eth0 rx 64; do echo -n .; done

and 'ping -f' toward the sh_eth port from another machine.

To fix this:
- Add a software flag (irq_enabled) to signal whether interrupts
  should be enabled
- In the interrupt handler, if the flag is clear then clear EESIPR
  and return
- In the NAPI poller, if the flag is clear then don't set EESIPR
- Set the flag before enabling interrupts in sh_eth_dev_init() and
  sh_eth_set_ringparam()
- Clear the flag and serialise with the interrupt and NAPI
  handlers before clearing EESIPR in sh_eth_close() and
  sh_eth_set_ringparam()

After this, I could run the loop for 100,000 iterations successfully.
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the device is down then no packet buffers should be allocated.
We also must not touch its registers as it may be powered off.
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We must only ever stop TX queues when they are full or the net device
is not 'ready' so far as the net core, and specifically the watchdog,
is concerned.  Otherwise, the watchdog may fire *immediately* if no
packets have been added to the queue in the last 5 seconds.

What's more, sh_eth_tx_timeout() will likely crash if called while
we're resizing the TX ring.

I could easily trigger this by running the loop:

   while ethtool -G eth0 rx 128 && ethtool -G eth0 rx 64; do echo -n .; done
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If an skb to be transmitted is shorter than the minimum Ethernet frame
length, we currently set the DMA descriptor length to the minimum but
do not add zero-padding.  This could result in leaking sensitive
data.  We also pass different lengths to dma_map_single() and
dma_unmap_single().

Use skb_padto() to pad properly, before calling dma_map_single().
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In Dual EMAC, the default VLANs are used to segregate Rx packets between
the ports, so adding the same default VLAN to the switch will affect the
normal packet transfers. So returning error on addition of dual EMAC
default VLANs.

Even if EMAC 0 default port VLAN is added to EMAC 1, it will lead to
break dual EMAC port separations.

Fixes: d9ba8f9e (driver: net: ethernet: cpsw: dual emac interface implementation)
Cc: <stable@vger.kernel.org> # v3.9+
Reported-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do not wait for channel command buffers in IPA commands.
The potential wait could be done while holding a spin lock and causes
in recent kernels such a bug if kernel lock debugging is enabled:

kernel: BUG: sleeping function called from invalid context at drivers/s390/net/qeth_core_main.c:
794
kernel: in_atomic(): 1, irqs_disabled(): 0, pid: 2031, name: NetworkManager
kernel: 2 locks held by NetworkManager/2031:
kernel:  #0:  (rtnl_mutex){+.+.+.}, at: [<00000000006e0d7a>] rtnetlink_rcv+0x32/0x50
kernel:  #1:  (_xmit_ETHER){+.....}, at: [<00000000006cfe90>] dev_set_rx_mode+0x30/0x50
kernel: CPU: 0 PID: 2031 Comm: NetworkManager Not tainted 3.18.0-rc5-next-20141124 #1
kernel:        00000000275fb1f0 00000000275fb280 0000000000000002 0000000000000000
               00000000275fb320 00000000275fb298 00000000275fb298 00000000007e326a
               0000000000000000 000000000099ce2c 00000000009b4988 000000000000000b
               00000000275fb2e0 00000000275fb280 0000000000000000 0000000000000000
               0000000000000000 00000000001129c8 00000000275fb280 00000000275fb2e0
kernel: Call Trace:
kernel: ([<00000000001128b0>] show_trace+0xf8/0x158)
kernel:  [<000000000011297a>] show_stack+0x6a/0xe8
kernel:  [<00000000007e995a>] dump_stack+0x82/0xb0
kernel:  [<000000000017d668>] ___might_sleep+0x170/0x228
kernel:  [<000003ff80026f0e>] qeth_wait_for_buffer+0x36/0xd0 [qeth]
kernel:  [<000003ff80026fe2>] qeth_get_ipacmd_buffer+0x3a/0xc0 [qeth]
kernel:  [<000003ff80105078>] qeth_l3_send_setdelmc+0x58/0xf8 [qeth_l3]
kernel:  [<000003ff8010b1fe>] qeth_l3_set_ip_addr_list+0x2c6/0x848 [qeth_l3]
kernel:  [<000003ff8010bbb4>] qeth_l3_set_multicast_list+0x434/0xc48 [qeth_l3]
kernel:  [<00000000006cfe9a>] dev_set_rx_mode+0x3a/0x50
kernel:  [<00000000006cff90>] __dev_open+0xe0/0x140
kernel:  [<00000000006d02a0>] __dev_change_flags+0xa0/0x178
kernel:  [<00000000006d03a8>] dev_change_flags+0x30/0x70
kernel:  [<00000000006e14ee>] do_setlink+0x346/0x9a0
...

The device driver has plenty of command buffers available
per channel for channel command communication.
In the extremely rare case when there is no command buffer
available, return a NULL pointer and issue a warning
in the kernel log. The caller handles the case when
a NULL pointer is encountered and returns an error.

In the case the wait for command buffer is possible
(because no lock is held as in the OSN case), still wait
until a channel command buffer is available.
Signed-off-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Reviewed-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the functions that are registering and unregistering MAC
addresses in the qeth-handled hardware, remove callback functions
that are unnesessary, as only the return code is analyzed.
Translate hardware response codes to semi-standard 'errno'-like
codes for readability.

Add kernel-doc description to the internal API function
qeth_send_control_data().
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Reviewed-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ip6_route_output() always returns a valid dst pointer unlike in IPv4
case. So the validation has to be different from the IPv4 path. Correcting
that error in this patch.

This was picked up by a static checker with a following warning -

   drivers/net/ipvlan/ipvlan_core.c:380 ipvlan_process_v6_outbound()
        warn: 'dst' isn't an ERR_PTR
Signed-off-by: NMahesh Bandewar <maheshb@google.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NAPI poll logic now enforces that a poller returns exactly the budget
when it wants to be called again.

If a driver limits TX completion, it has to return budget as well when
the limit is hit, not the number of received packets.
Reported-and-tested-by: NMike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Fixes: d75b1ade ("net: less interrupt masking in NAPI")
Cc: Manish Chopra <manish.chopra@qlogic.com>
Acked-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the commit d75b1ade ("net: less interrupt masking in NAPI") napi repoll
is done only when work_done == budget. When we are in busy_poll we return 0 in
napi_poll. We should return budget.
Signed-off-by: NGovindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Updated hardware documention shows the Rx flow control settings were
moved from the Rx queue operation mode register to a new Rx queue flow
control register.  The old flow control settings are now reserved areas
of the Rx queue operation mode register. Update the code to use the new
register.
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Put controller into init mode in network stop to end pending transmissions. The
issue is observed in cases when transmitted frame is not acked.
Signed-off-by: NViktor Babrian <babrian.viktor@renyi.mta.hu>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

"sp->desc[i]" has 25 characters.  "dev->name" has 15 characters.  If we
used all 15 characters then the sprintf() would overflow.

I changed the "sprintf(sp->name, "%s Neterion %s"" to snprintf(), as
well, even though it can't overflow just to be consistent.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Read OCP register 0xa43a~0xa43b would clear some flags which the hw
would use, and it may let the device lost. However, the unit of
reading is 4 bytes. That is, it would read 0xa438~0xa43b when calling
sram_read() to read OCP_SRAM_DATA.
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For ocp_write_word() and ocp_write_byte(), there is a generic_ocp_read()
which is used to read the whole 4 byte data, keep the unchanged bytes,
and modify the expected bytes. However, the "byen" could be used to
determine which bytes of the 4 bytes to write, so the action could be
removed.
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IRQs should only get activated when there is nothing to poll in the
queue any more and to after every poll.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

napi should get registered before the netdev and not after.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver connects and disconnects the PHY device whenever the
net device is brought up and down.  The ethtool get_settings,
set_settings and nway_reset operations will dereference a null
or dangling pointer if called while it is down.

I think it would be preferable to keep the PHY connected, but there
may be good reasons not to.

As an immediate fix for this bug:
- Set the phydev pointer to NULL after disconnecting the PHY
- Change those three operations to return -ENODEV while the PHY is
  not connected
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently net_device_ops::set_rx_mode is only implemented for
chips with a TSU (multiple address table).  However we do need
to turn the PRM (promiscuous) flag on and off for other chips.

- Remove the unlikely() from the TSU functions that we may safely
  call for chips without a TSU
- Make setting of the MCT flag conditional on the tsu capability flag
- Rename sh_eth_set_multicast_list() to sh_eth_set_rx_mode() and plumb
  it into both net_device_ops structures
- Remove the previously-unreachable branch in sh_eth_rx_mode() that
  would otherwise reset the flags to defaults for non-TSU chips
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To fix invalid hardware accesses, the commit 872b5d81 ("ath9k: do not
access hardware on IRQs during reset") made the irq handler ignore interrupts
emitted after queueing a hardware reset (which disables the IRQ). This left a
small time window for the IRQ to get re-enabled by the tasklet, which caused
IRQ storms.  Instead of returning IRQ_NONE when ATH_OP_HW_RESET is set, disable
the IRQ entirely for the duration of the reset.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

Timur reports that this code crashes if nfunctions is 0. Fix the
loop iteration to only consider valid elements of the functions
array.
Reported-by: NTimur Tabi <timur@codeaurora.org>
Cc: Pramod Gurav <pramod.gurav@smartplayin.com>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: Ivan T. Ivanov <iivanov@mm-sol.com>
Cc: Andy Gross <agross@codeaurora.org>
Fixes: 32745581 "pinctrl: qcom: Add support for reset for apq8064"
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When we have an active scheduled scan, and the RFKILL
interrupt kicks in, the stack will cancel the scheduled
scan as part of the down flow. But cancelling scheduled
scan usually implies sending a command to the firwmare
which has been killed as part of the RFKILL interrupt
handling.
Because of that, we returned an error to mac80211 when
it asked to stop the scheduled scan and didn't notify the
end of the scheduled scan. Besides a fat warning, this led
to a situation in which cfg80211 would refuse any new scan
request.

To disentangle this, fake that the scheduled scan has been
stopped without sending the command to the firwmare, return
0 after having properly let cfg80211 know that the scan
has been cancelled.

This is basically the same as:
commit 9b520d84
Author: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Date:   Tue Nov 4 15:54:11 2014 +0200

    iwlwifi: mvm: abort scan upon RFKILL

    This code existed but not for all the different FW APIs
    we support.
    Fix this.

but for the scheduled scan case.

Link: http://permalink.gmane.org/gmane.linux.kernel.wireless.general/133232Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.
Signed-off-by: NStanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

This reverts commit da788acb.

That commit tried to fix the section mismatch warning by moving the
ppc_corenet_clk_driver struct to init section. This is definitely wrong
because the kernel would free the memories occupied by this struct
after boot while this driver is still registered in the driver core.
The kernel would panic when accessing this driver struct.

Cc: stable@vger.kernel.org # 3.17
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Acked-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Lockdep reported a possible deadlock between the cpuclk lock and for example
the i2c driver.

       CPU0                    CPU1
       ----                    ----
  lock(clk_lock);
                               local_irq_disable();
                               lock(&(&i2c->lock)->rlock);
                               lock(clk_lock);
  <Interrupt>
    lock(&(&i2c->lock)->rlock);

 *** DEADLOCK ***

The generic clock-types of the core ccf already use spin_lock_irqsave when
touching clock registers, so do the same for the cpuclk.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed initialization of "flags"]

Call spin_lock_init() before the spinlocks are used, both in early init
and probe functions preventing a lockdep splat.

I have been observing lockdep complaining [1] during boot on my a80 optimus [2]
when CONFIG_PROVE_LOCKING has been enabled. This patch resolves the splat,
and has been tested on a few other sunxi platforms without issue.

[1] http://storage.kernelci.org/next/next-20150107/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-tbaker/boot-sun9i-a80-optimus.html
[2] http://kernelci.org/boot/?a80-optimusSigned-off-by: NTyler Baker <tyler.baker@linaro.org>
Cc: <stable@vger.kernel.org>
Acked-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

The arm-cci driver completes the probe sequence even if the cci node is
marked as disabled. Add a check in the driver to honour the cci status
in the device tree.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

On dm816x we have two emac controllers with separate memory
areas.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some devices like dm816x have the MDIO registers within the first EMAC
instance address space. Let's fix the issue by allowing to pass an
optional second IO range for the EMAC control register area.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Looks like the phy_id is never set up beyond getting the phandle.
Note that we can remove the ifdef for phy_node as there is a stub
for of_phy_connec() if CONFIG_OF is not set.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We only use clk_get() to get the frequency, the rest is done by
the runtime PM calls. Let's free the clock too.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 3ba97381 ("net: ethernet: davinci_emac: add pm_runtime support")
added support for runtime PM, but it causes issues on omap3 related devices
that actually gate the clocks:

Unhandled fault: external abort on non-linefetch (0x1008)
...
[<c04160f0>] (emac_dev_getnetstats) from [<c04d6a3c>] (dev_get_stats+0x78/0xc8)
[<c04d6a3c>] (dev_get_stats) from [<c04e9ccc>] (rtnl_fill_ifinfo+0x3b8/0x938)
[<c04e9ccc>] (rtnl_fill_ifinfo) from [<c04eade4>] (rtmsg_ifinfo+0x68/0xd8)
[<c04eade4>] (rtmsg_ifinfo) from [<c04dd35c>] (register_netdevice+0x3a0/0x4ec)
[<c04dd35c>] (register_netdevice) from [<c04dd4bc>] (register_netdev+0x14/0x24)
[<c04dd4bc>] (register_netdev) from [<c041755c>] (davinci_emac_probe+0x408/0x5c8)
[<c041755c>] (davinci_emac_probe) from [<c0396d78>] (platform_drv_probe+0x48/0xa4)

Let's fix it by moving the pm_runtime_get() call earlier, and also add it to
the emac_dev_getnetstats(). Also note that we want to use pm_runtime_get_sync()
as we don't want to have deferred_resume happen. And let's also check the
return value for pm_runtime_get_sync() as noted by Felipe Balbi <balbi@ti.com>.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On davinci_emac, we have pulse interrupts. This means that we need to
clear the EOI bits when disabling interrupts as otherwise the interrupts
keep happening. And we also need to not clear the EOI bits again when
enabling the interrupts as otherwise we will get tons of:

unexpected IRQ trap at vector 00

These errors almost certainly mean that the omap-intc.c is signaling
a spurious interrupt with the reserved irq 127 as we've seen earlier
on omap3.

Let's fix the issue by clearing the EOI bits when disabling the
interrupts. Let's also keep the comment for "Rx Threshold and Misc
interrupts are not enabled" for both enable and disable so people
are aware of this when potentially adding more support.

Note that eventually we should handle the RX and TX interrupts
separately like cpsw is now doing. However, so far I have not seen
any issues with this based on my testing, so it seems to behave a
little different compared to the cpsw that had a similar issue.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Except for VXLAN steering rules, all offloads should work as they were
under plain DMFS mode. Fix that by enabling all the offloads under
DMFS-A0 mode, except for VXLAN steering rules.

Fixes: d57febe1 "net/mlx4: Add A0 hybrid steering"
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes double kfree() calls at init_rx_ring() because
it causes static checker warning.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NByungho An <bh74.an@samsung.com>
Signed-off-by: NKukjin Kim <kgene@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the MAC address is provided in the device tree file, the
condition is true and kernel crashes due to NULL dereference.
Signed-off-by: NGirish K.S <ks.giri@samsung.com>
Signed-off-by: NByungho An <bh74.an@samsung.com>
Signed-off-by: NKukjin Kim <kgene@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit b284fbe3 ("sh_eth: Fix access to TRSCER register") wanted
to add a .trscer_err_mask value to the R-Car Gen2 family-specific data
structure (r8a779x_data), but it was accidentally added to the
SH7724-specific data structure (sh7724_data).

Presumably this happened due to a patch conflict with commit
d407bc02 ("sh-eth: Set fdr_value of R-Car SoCs"), which added
another field at the same position.

Move the field setting to fix this.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Fixes: b284fbe3 ("sh_eth: Fix access to TRSCER register")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

while adding vlan in dual EMAC mode, only specific ports should be
subscribed for the vlan, else it will lead to switching mode and
if both ports connected to same switch cpsw will hung as it creates
a network loop. Fixing this by adding only specific ports in case
of dual EMAC.
Signed-off-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_get_named_gpiod_flags fails with -EPROBE_DEFER in cases
where the gpio chip is available and the GPIO translation fails.

This causes drivers to be re-probed erroneusly, and hides the
real problem(i.e. the GPIO number being out of range).

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: NHans Holmberg <hans.holmberg@intel.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Fix attribute-creation race with userspace by using the default group
to create also the contingent gpio device attributes.

Fixes: d8f388d8 ("gpio: sysfs interface")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>