This patch fixes spelling warnings generated by checkpatch.pl
Signed-off-by: Roger H. Newell <newell.roger@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove parentheses around the right hand side of assignments. They are
unnecessary.
Semantic patch:
@@
expression a, b, c;
@@
(
a = (b == c)
|
a =
- (
b
- )
)
Signed-off-by: Janani Ravichandran <janani.rvchndrn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the unnecessary parens on right hand side of assignment.
Found using Coccinelle:
@@
identifier x;
expression e1, e2;
@@
- x = (e1 << e2)
+ x = e1 << e2
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch renames the name of counter variable to i.
This change makes more readability because wilc_send_config_pkt has a
similar argument name as count.
Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to set to 0 for counter variable before entering next
for-loop statement because counter is initialized again in for-loop
statement, so just remove it.
Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
counter is used as for-loop control variable and indicating index of
struct wid array so that it is better to use int type.
There is no need to set to 0 when it is declared at the top of this
function. It is initialized as 0 in for-loop statement.
Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wilc_send_config_pkt is returned 0 or -ETIMEDOUT according to return
value of wilc_wlan_cfg_set or wilc_wlan_cfg_set.
It is better to use int type to represent linux standard error code.
Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There was a missing curly brace so this function returns failure instead
of succeeding.
Fixes: 06fb9336ac ('staging: wilc1000: wilc_wfi_cfgoperations.c: replaces PRINT_ER with netdev_err')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LUSTRE_VERSION_ALLOWED_OFFSET is only used on the server to disallow
connection of old userspace clients.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While initial code drop was corresponding to 2.3.64, lots of
different changes went in since then, and also quite a bunch of fixes,
but almost none of the new features.
Code-wise we are almost at 2.5.0, so let's call it 2.4.60 - this is a
version that was never reached in the actual pre-2.5 development, so
it should be a clear distinction of where we are now.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
New test scripts expect spaces around state names and square brackets
when parsing debugfs output, so add them to avoid false failures.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When gettng an invalid create request in echo code (wrong group,
or no group at all), just return an error instead of crashing.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dan Carpenter noticed that since we already checked for
(oa->o_valid & OBD_MD_FLID) == 0, that means
(oa->o_valid & OBD_MD_FLID) is always true after that so
no point in checking for it.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Take the size of a dereference to a variable rather than the associated
type, to make the code more resistant to type changes in the future.
The type of the pointer variable here is the same as the type in the
argument that is being replaced in sizeof().
Signed-off-by: Janani Ravichandran <janani.rvchndrn@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove unusefull return at the end of void function.
WARNING: void function return statements are not generally useful.
Signed-off-by: Rakhi Sharma <rakhish1994@gmail.com>
Changes in v3:
shortened the subject line and make the discription more clear.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is an anonymous struct which is actually used as a bitmap. So
convert the struct to a bitmap and change code accordingly where
needed.
This also allows for a cleanup of set_data_bits and set_ctrl_bits as
they can use a common helper now. The helper can also be converted to
a for loop instead of doing bit OR. And given it is a for loop now,
bit masking (using BIT_MSK) is moved from the callers there too.
Signed-off-by: Daniel Chromik <daniel.chromik@seznam.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Acked-by: Willy Tarreau <willy@haproxy.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix double freeing of the cb that can happen if link reset kicks in the
middle of blocked write from a device on the cl bus.
Free cb inside mei_cl_write function on failure and drop cb free
operation from callers, during a link reset the mei_cl_write function
returns with an error, but the caller doesn't know if the cb was
already queued or not so it doesn't know if the cb will be freed upon
queue reclaim or it has to free it itself.
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit adds support to the eeprom_93x46 driver allowing a GPIO line
to function as a 'select' or 'enable' signal prior to accessing the
EEPROM.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
Tested-by: Chris Healy <chris.healy@zii.aero>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Atmel devices in this family have some quirks not found in other similar
chips - they do not support a sequential read of the entire EEPROM
contents, and the control word sent at the start of each operation
varies in bit length.
This commit adds quirk support to the driver and modifies the read
implementation to support non-sequential reads for consistency with
other misc/eeprom drivers.
Tested on a custom Freescale VF610-based platform, with an AT93C46D
device attached via dspi2. The spi-gpio driver was used to allow the
necessary non-byte-sized transfers.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
Tested-by: Chris Healy <chris.healy@zii.aero>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1_process() calls try_to_freeze(), but the thread doesn't mark itself
freezable through set_freezable(), so the try_to_freeze() call is useless.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code fails to nvmem_cell_drop(cells[0]) - even worse, if
the loop above fails already at i==0, we'll enter an essentially
infinite loop doing nvmem_cell_drop on cells[-1], cells[-2], ... which
is unlikely to end well.
Also, we're not freeing the temporary backing array cells on the error
path.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/built-in.o: In function `uv_bios_call':
(.text+0xeba00): undefined reference to `efi_call'
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pfn_t type uses an unsigned long to store a pfn + flags value. On a
64-bit platform the upper 12 bits of an unsigned long are never used for
storing the value of a pfn. However, this is not true on highmem
platforms, all 32-bits of a pfn value are used to address a 44-bit
physical address space. A pfn_t needs to store a 64-bit value.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=112211
Fixes: 01c8f1c44b ("mm, dax, gpu: convert vm_insert_mixed to pfn_t")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Stuart Foster <smf.linux@ntlworld.com>
Reported-by: Julian Margetson <runaway@candw.ms>
Tested-by: Julian Margetson <runaway@candw.ms>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike said:
: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i. e
: kernel with CONFIG_UBSAN_ALIGNMENT fails to load without even any error
: message.
:
: The problem is that ubsan callbacks use spinlocks and might be called
: before lockdep is initialized. Particularly this line in the
: reserve_ebda_region function causes problem:
:
: lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
:
: If i put lockdep_init() before reserve_ebda_region call in
: x86_64_start_reservations kernel loads well.
Fix this ordering issue permanently: change lockdep so that it uses
hlists for the hash tables. Unlike a list_head, an hlist_head is in its
initialized state when it is all-zeroes, so lockdep is ready for
operation immediately upon boot - lockdep_init() need not have run.
The patch will also save some memory.
lockdep_init() and lockdep_initialized can be done away with now - a 4.6
patch has been prepared to do this.
Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This showed up on ARC when running LMBench bw_mem tests as Overlapping
TLB Machine Check Exception triggered due to STLB entry (2M pages)
overlapping some NTLB entry (regular 8K page).
bw_mem 2m touches a large chunk of vaddr creating NTLB entries. In the
interim khugepaged kicks in, collapsing the contiguous ptes into a
single pmd. pmdp_collapse_flush()->flush_pmd_tlb_range() is called to
flush out NTLB entries for the ptes. This for ARC (by design) can only
shootdown STLB entries (for pmd). The stray NTLB entries cause the
overlap with the subsequent STLB entry for collapsed page. So make
pmdp_collapse_flush() call pte flush interface not pmd flush.
Note that originally all thp flush call sites in generic code called
flush_tlb_range() leaving it to architecture to implement the flush for
pte and/or pmd. Commit 12ebc1581a changed this by calling a new
opt-in API flush_pmd_tlb_range() which made the semantics more explicit
but failed to distinguish the pte vs pmd flush in generic code, which is
what this patch fixes.
Note that ARC can fixed w/o touching the generic pmdp_collapse_flush()
by defining a ARC version, but that defeats the purpose of generic
version, plus sementically this is the right thing to do.
Fixes STAR 9000961194: LMBench on AXS103 triggering duplicate TLB
exceptions with super pages
Fixes: 12ebc1581a ("mm,thp: introduce flush_pmd_tlb_range")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org> [4.4]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to use post-decrement to get percpu_counter_destroy() called on
&wb->stat[0]. Moreover, the pre-decremebt would cause infinite
out-of-bounds accesses if the setup code failed at i==0.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAX implements split_huge_pmd() by clearing pmd. This simple approach
reduces memory overhead, as we don't need to deposit page table on huge
page mapping to make split_huge_pmd() never-fail. PTE table can be
allocated and populated later on page fault from backing store.
But one side effect is that have to check if pmd is pmd_none() after
split_huge_pmd(). In most places we do this already to deal with
parallel MADV_DONTNEED.
But I found two call sites which is not affected by MADV_DONTNEED (due
down_write(mmap_sem)), but need to have the check to work with DAX
properly.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kptr_restrict flag, when set to 1, only prints the kernel address
when the user has CAP_SYSLOG. When it is set to 2, the kernel address
is always printed as zero. When set to 1, this needs to check whether
or not we're in IRQ.
However, when set to 2, this check is unneccessary, and produces
confusing results in dmesg. Thus, only make sure we're not in IRQ when
mode 1 is used, but not mode 2.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add missing kernel-doc notation for function parameter 'gfp_mask' to fix
kernel-doc warning.
mm/filemap.c:1898: warning: No description found for parameter 'gfp_mask'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When enabling UBSAN_SANITIZE_ALL, the kernel image size gets increased
significantly (~3x). So, it sounds better to have some note in Kconfig.
And, fixed a typo.
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sync to upstream dtc commit b06e55c88b9b ("Prevent crash on modulo by
zero"). This adds the following commits from upstream:
b06e55c Prevent crash on modulo by zero
b433450 Fix some bugs in processing of line directives
d728ad5 Fix crash on nul character in string escape sequence
1ab2205 Gracefully handle bad octal literals
1937095 Prevent crash on division by zero
d0b3ab0 libfdt: Fix undefined behaviour in fdt_offset_ptr()
d4c7c25 libfdt: check for potential overrun in _fdt_splice()
f58799b libfdt: Add some missing symbols to version.lds
af9f26d Remove duplicated -Werror in dtc Makefile
604e61e fdt: Add functions to retrieve strings
8702bd1 fdt: Add a function to get the index of a string
2218387 fdt: Add a function to count strings
554fde2 libfdt: fix comment block of fdt_get_property_namelen()
e5e6df7 fdtdump: Fix bug printing bytestrings with negative values
067829e Remove redundant fdtdump test code
897a429 Move fdt_path_offset alias tests to right tests section
2d1417c Add simple .travis.yml
f6dbc6c guess output file format
5e78dff guess input file format based on file content or file name
8b927bf tests: convert `echo -n` to `printf`
64c46b0 Fix crash with poorly defined #size-cells
Cc: Grant Likely <grant.likely@linaro.org>
Tested-by: Frank Rowand <frank.rowand@sonymobile.com>
Reviewed-by: Frank Rowand <frank.rowand@sonymobile.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Recent versions of libfdt add a dependency on strnlen. Copy the
implementation in lib/string.c here, so we can update libfdt.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rob Herring <robh@kernel.org>
If kernel config options are not properly set, "make scripts" will not
compile dtc. Update the unable to find dtc error message to check
the kernel config and give better advice on how to create dtc.
Reword another error message to increase clarity.
Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com>
Signed-off-by: Rob Herring <robh@kernel.org>
With gdsc driver capable of handling hierarchical power domains,
specify oxili_gdsc as parent of oxilicx_gdsc.
Remove all direct calls to genpd from the mmcc clock driver. The
adding and removing of subdomains is now handled from within
the gdsc driver.
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Add all gdsc data which are part of mmcc on msm8996 family
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Add all data for the GDSCs which are part of msm8996 GCC block
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Some gdscs might be controlled via voting registers and might not
really disable when the kernel intends to disable them (due to other
votes keeping them enabled)
Mark these gdscs with a flag for we do not check/wait on a disable
status for these gdscs within the kernel disable callback.
Also at boot, if these GDSCs are found to be ON, we make sure we
vote for them before we inform the genpd framework about their
status. If genpd gets no users, it then disables (removes the vote)
them as part of genpd_poweroff_unused()
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Some gdsc power domains can have a gds_hw_controller block inside
to help ensure all slave devices within the power domain are idle
before the gdsc is actually switched off.
This is mainly useful in power domains which host a MMU, in which
case its necessary to make sure there are no outstanding MMU operations
or pending bus transactions before the power domain is turned off.
In gdscs with gds_hw_controller block, its necessary to check the
gds_hw_ctrl status bits instead of the ones in gdscr, to determine
the state of the powerdomain.
While at it, also move away from using jiffies and use ktime APIs
instead for busy looping on status bits.
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Some qcom SoCs' can have hierarchical power domains. Let the gdsc structs
specify the parents (if any) and the driver add genpd subdomains for them.
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The existing msi-map code is fine for shifting the entire RID space
upwards, but attempting finer-grained remapping reveals a bug. It turns
out that we are mistakenly treating the msi-base part as an offset, not
as a new base to remap onto, so things get squiffy when rid-base is
nonzero. Fix this, and at the same time add a sanity check against
having msi-map-mask clash with a nonzero rid-base, as that's another
thing one can easily get wrong.
CC: <stable@vger.kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Stuart Yoder <stuart.yoder@nxp.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Commit 7d34d56ef3 (PM / OPP: Disable OPPs that aren't supported by
the regulator) causes a crash to happen on Tegra124 Jetson TK1 when
using the DFLL clock source for the CPU. The DFLL manages the voltage
itself and so there is no regulator specified for the OPPs and so we
get a crash when we try to dereference the regulator pointer. Fix
this by checking to see if the regulator IS_ERR_OR_NULL before
dereferencing it.
Fixes: 7d34d56ef3 (PM / OPP: Disable OPPs that aren't supported by the regulator)
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is generally more efficient to submit larger IO.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The function returns true when the controller can't handle IO.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Go directly to ending a request if it wasn't started. Previously, completing a
request may invoke a driver callback for a request it didn't initialize.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The new queue limit is not used by the majority of block drivers, and
should be initialized to 0 for the driver's requested settings to be used.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This enables the GPIO-a support for Broadcom NSP SoC
Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yrdreddy@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Every time a descriptor is retrieved from the gpiolib, we issue
module_get() to reference count the module supplying the GPIOs.
We also need to call device_get() and device_put() as we also
reference the backing gpio_device when doing this.
Since the sysfs GPIO interface is using gpiod_get() this will
also reference count the sysfs requests until all GPIOs are
unexported.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>