Both the dma_pl330_dmac and the pl330_dmac struct have the same lifetime and the
separation of them is a relict of this having been two different drivers in the
past. Merging them into one struct makes the code a bit simpler as it for
example allows to remove the pointers going back and forth between the two
structs.

While we are at it also directly embed the pl330_info struct into the
pl330_dmac struct as this allows to remove some more redundant fields.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Since we keep a pointer to the manager thread it is fairly easy to check if a
thread is the manager thread.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

We know that we do not create invalid ccr settings in this driver. There is no
need to validate them.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The pl330_chid field of the dma_pl330_chan struct always holds a pointer to the
thread that is associated with the channel. Changing its type form void * to
struct pl330_thread makes things more type safe and removes the need for
unnecessary typecasts. While we are at it also rename the field from the cryptic
pl330_chid to thread.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The xfer_cb callback of the pl330_req struct is always set to the same function.
This adds an unnecessary step of indirection. Instead just call the callback
function directly.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The mc_len is initialized but its value is never read again, so remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The next field is always NULL, so we can remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The field is completely unused, remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The dmac_reset() callaback of the pl330_info struct is always set to NULL, so
remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The pl330_chanstatus struct is completely unused, so remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The settings for destination and source cache control are exactly the same. This
patch removes the duplicated enum and uses the same for both destination and
source cache control.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The pl330 driver has the custom pl330_reqtype enum which has the same possible
settings as the generic dma_transfer_direction enum. Switching over to the
generic enum internally makes it possible to directly initialize it from the
transfer request direction.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

To be able to see debug messages during boot, enable the debug settings
from Kconfig also for drivers in subdirectories.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

During the last few years, several inline wrappers for DMA operations have
been introduced:
  - commit 16052827 ("dmaengine/dma_slave:
    introduce inline wrappers"),
  - commit a14acb4a ("DMAEngine: add
    dmaengine_prep_interleaved_dma wrapper for interleaved api"),
  - commit 6e3ecaf0 ("dmaengine: add
    wrapper functions for device control functions").

Update the documentation to use the wrappers.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Use the zeroing function instead of dma_alloc_coherent & memset(,0,)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds support for end of transaction (EOT) and notify when done (NWD)
hardware descriptor flags.

The EOT flag requests that the peripheral assert an end of transaction interrupt
when that descriptor is complete.  It also results in special signaling protocol
that is used between the attached peripheral and the core using the DMA
controller.  Clients will specify DMA_PREP_INTERRUPT to enable this flag.

The NWD flag requests that the peripheral wait until the data has been fully
processed by the peripheral before moving on to the next descriptor.  Clients
will specify DMA_PREP_FENCE to enable this flag.
Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Fix the potential risk when enable config NET_DMA and ASYNC_TX. Async_tx is
lack of support in current release process of dma descriptor, all descriptors
will be released whatever is acked or no-acked by async_tx, so there is a
potential race condition when dma engine is uesd by others clients (e.g. when
enable NET_DMA to offload TCP).

In our case, a race condition which is raised when use both of talitos and
dmaengine to offload xor is because napi scheduler will sync all pending
requests in dma channels, it affects the process of raid operations due to
ack_tx is not checked in fsl dma. The no-acked descriptor is freed which is
submitted just now, as a dependent tx, this freed descriptor trigger
BUG_ON(async_tx_test_ack(depend_tx)) in async_tx_submit().

TASK = ee1a94a0[1390] 'md0_raid5' THREAD: ecf40000 CPU: 0
GPR00: 00000001 ecf41ca0 ee44/921a94a0 0000003f 00000001 c00593e4 00000000 00000001
GPR08: 00000000 a7a7a7a7 00000001 045/920000002 42028042 100a38d4 ed576d98 00000000
GPR16: ed5a11b0 00000000 2b162000 00000200 046/920000000 2d555000 ed3015e8 c15a7aa0
GPR24: 00000000 c155fc40 00000000 ecb63220 ecf41d28 e47/92f640bb0 ef640c30 ecf41ca0
NIP [c02b048c] async_tx_submit+0x6c/0x2b4
LR [c02b068c] async_tx_submit+0x26c/0x2b4
Call Trace:
[ecf41ca0] [c02b068c] async_tx_submit+0x26c/0x2b448/92 (unreliable)
[ecf41cd0] [c02b0a4c] async_memcpy+0x240/0x25c
[ecf41d20] [c0421064] async_copy_data+0xa0/0x17c
[ecf41d70] [c0421cf4] __raid_run_ops+0x874/0xe10
[ecf41df0] [c0426ee4] handle_stripe+0x820/0x25e8
[ecf41e90] [c0429080] raid5d+0x3d4/0x5b4
[ecf41f40] [c04329b8] md_thread+0x138/0x16c
[ecf41f90] [c008277c] kthread+0x8c/0x90
[ecf41ff0] [c0011630] kernel_thread+0x4c/0x68

Another modification in this patch is the change of completed descriptors,
there is a potential risk which caused by exception interrupt, all descriptors
in ld_running list are seemed completed when an interrupt raised, it works fine
under normal condition, but if there is an exception occured, it cannot work as
our excepted. Hardware should not be depend on s/w list, the right way is to
read current descriptor address register to find the last completed descriptor.
If an interrupt is raised by an error, all descriptors in ld_running should not
be seemed finished, or these unfinished descriptors in ld_running will be
released wrongly.

A simple way to reproduce:
Enable dmatest first, then insert some bad descriptors which can trigger
Programming Error interrupts before the good descriptors. Last, the good
descriptors will be freed before they are processsed because of the exception
intrerrupt.

Note: the bad descriptors are only for simulating an exception interrupt.  This
case can illustrate the potential risk in current fsl-dma very well.
Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds suspend and resume functions for Freescale DMA driver.
Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The usage of spin_lock_irqsave() is a stronger locking mechanism than is
required throughout the driver. The minimum locking required should be used
instead. Interrupts will be turned off and context will be saved, it is
unnecessary to use irqsave.

This patch changes all instances of spin_lock_irqsave() to spin_lock_bh(). All
manipulation of protected fields is done using tasklet context or weaker, which
makes spin_lock_bh() the correct choice.
Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Pull ext4 bugfixes from Ted Ts'o:
 "More bug fixes for ext4 -- most importantly, a fix for a bug
  introduced in 3.15 that can end up triggering a file system corruption
  error after a journal replay.

  It shouldn't lead to any actual data corruption, but it is scary and
  can force file systems to be remounted read-only, etc"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix potential null pointer dereference in ext4_free_inode
  ext4: fix a potential deadlock in __ext4_es_shrink()
  ext4: revert commit which was causing fs corruption after journal replays
  ext4: disable synchronous transaction batching if max_batch_time==0
  ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()
  ext4: clarify error count warning messages
  ext4: fix unjournalled bg descriptor while initializing inode bitmap

Pull clock driver fixes from Mike Turquette:
 "This batch of fixes is for a handful of clock drivers from Allwinner,
  Samsung, ST & TI.  Most of them are of the "this hardware won't work
  without this fix" variety, including patches that fix platforms that
  did not boot under certain configurations.  Other fixes are the result
  of changes to the clock core introduced in 3.15 that had subtle
  impacts on the clock drivers.

  There are no fixes to the clock framework core in this pull request"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: spear3xx: Set proper clock parent of uart1/2
  clk: spear3xx: Use proper control register offset
  clk: qcom: HDMI source sel is 3 not 2
  clk: sunxi: fix devm_ioremap_resource error detection code
  clk: s2mps11: Fix double free corruption during driver unbind
  clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
  clk: exynos5420: Remove aclk66_peric from the clock tree description
  clk/exynos5250: fix bit number for tv sysmmu clock
  clk: s3c64xx: Hookup SPI clocks correctly
  clk: samsung: exynos4: Remove SRC_MASK_ISP gates
  clk: samsung: add more aliases for s3c24xx
  clk: samsung: fix several typos to fix boot on s3c2410
  clk: ti: set CLK_SET_RATE_NO_REPARENT for ti,mux-clock
  clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
  clk: ti: dra7: return error code in failure case
  clk: ti: apll: not allocating enough data

Pull ARM SoC fixes from Olof Johansson:
 "This week's arm-soc fixes:

   - Another set of OMAP fixes
     * Clock fixes
     * Restart handling
     * PHY regulators
     * SATA hwmod data for DRA7
     + Some trivial fixes and removal of a bit of dead code
   - Exynos fixes
     * A bunch of clock fixes
     * Some SMP fixes
     * Exynos multi-core timer: register as clocksource and fix ftrace.
     + a few other minor fixes

  There's also a couple more patches, and at91 fix for USB caused by
  common clock conversion, and more MAINTAINERS entries for shmobile.

  We're definitely switching to only regression fixes from here on out,
  we've been a little less strict than usual up until now"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (26 commits)
  ARM: at91: at91sam9x5: add clocks for usb device
  ARM: EXYNOS: Register cpuidle device only on exynos4210 and 5250
  ARM: dts: Add clock property for mfc_pd in exynos5420
  clk: exynos5420: Add IDs for clocks used in PD mfc
  ARM: EXYNOS: Add support for clock handling in power domain
  ARM: OMAP2+: Remove non working OMAP HDMI audio initialization
  ARM: imx: fix shared gate clock
  ARM: dts: Update the parent for Audss clocks in Exynos5420
  ARM: EXYNOS: Update secondary boot addr for secure mode
  ARM: dts: Fix TI CPSW Phy mode selection on IGEP COM AQUILA.
  ARM: dts: am335x-evmsk: Enable the McASP FIFO for audio
  ARM: dts: am335x-evm: Enable the McASP FIFO for audio
  ARM: OMAP2+: Make GPMC skip disabled devices
  ARM: OMAP2+: create dsp device only on OMAP3 SoCs
  ARM: dts: dra7-evm: Make VDDA_1V8_PHY supply always on
  ARM: DRA7/AM43XX: fix header definition for omap44xx_restart
  ARM: OMAP2+: clock/dpll: fix _dpll_test_fint arithmetics overflow
  ARM: DRA7: hwmod: Add SYSCONFIG for usb_otg_ss
  ARM: DRA7: hwmod: Fixup SATA hwmod
  ARM: OMAP3: PRM/CM: Add back macros used by TI DSP/Bridge driver
  ...

Pull ARM fixes from Russell King:
 "Another round of fixes for ARM:
   - a set of kprobes fixes from Jon Medhurst
   - fix the revision checking for the L2 cache which wasn't noticed to
     have been broken"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: l2c: fix revision checking
  ARM: kprobes: Fix test code compilation errors for ARMv4 targets
  ARM: kprobes: Disallow instructions with PC and register specified shift
  ARM: kprobes: Prevent known test failures stopping other tests running

Pull m68k fixes from Geert Uytterhoeven:
 "Summary:
  - Fix for a boot regression introduced in v3.16-rc1,
  - Fix for a build issue in -next"

Christoph Hellwig questioned why mach_random_get_entropy should be
exported to modules, and Geert explains that random_get_entropy() is
called by at least the crypto layer and ends up using it on m68k.  On
most other architectures it just uses get_cycles() (which is typically
inlined and doesn't need exporting),

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Export mach_random_get_entropy to modules
  m68k: Fix boot regression on machines with RAM at non-zero

Pull parisc fixes from Helge Deller:
 "The major patch in here is one which fixes the fanotify_mark() syscall
  in the compat layer of the 64bit parisc kernel.  It went unnoticed so
  long, because the calling syntax when using a 64bit parameter in a
  32bit syscall is quite complex and even worse, it may be even
  different if you call syscall() or the glibc wrapper.  This patch
  makes the kernel accept the calling convention when called by the
  glibc wrapper.

  The other two patches are trivial and remove unused headers, #includes
  and adds the serial ports of the fastest C8000 workstation to the
  parisc-kernel internal hardware database"

* 'parisc-3.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: drop unused defines and header includes
  parisc: fix fanotify_mark() syscall on 32bit compat kernel
  parisc: add serial ports of C8000/1GHz machine to hardware database

The uarts only work when the parent is ras_ahb_clk. The stale 3.5
based ST tree does this in the board file.

Add it to the clk init function. Not pretty, but the mess there is
amazing anyway.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The control register is at offset 0x10, not 0x0. This is wreckaged
since commit 5df33a62 (SPEAr: Switch to common clock framework).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

On parisc we can not use the existing compat implementation for fanotify_mark()
because for the 64bit mask parameter the higher and lower 32bits are ordered
differently than what the compat function expects from big endian
architectures.

Specifically:
It finally turned out, that on hppa we end up with different assignments
of parameters to kernel arguments depending on if we call the glibc
wrapper function
 int fanotify_mark (int __fanotify_fd, unsigned int __flags,
                    uint64_t __mask, int __dfd, const char *__pathname);
or directly calling the syscall manually
 syscall(__NR_fanotify_mark, ...)

Reason is, that the syscall() function is implemented as C-function and
because we now have the sysno as first parameter in front of the other
parameters the compiler will unexpectedly add an empty paramenter in
front of the u64 value to ensure the correct calling alignment for 64bit
values.
This means, on hppa you can't simply use syscall() to call the kernel
fanotify_mark() function directly, but you have to use the glibc
function instead.

This patch fixes the kernel in the hppa-arch specifc coding to adjust
the parameters in a way as if userspace calls the glibc wrapper function
fanotify_mark().
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

Pull slave-dmaengine fixes from Vinod Koul:
 "We have two small fixes.  First one from Daniel to handle 0-length
  packets for usb cppi dma.  Second by Russell for imx-sdam cyclic
  residue reporting"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  Update imx-sdma cyclic handling to report residue
  dma: cppi41: handle 0-length packets

Merge tag 'samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes

Merge "Samsung fixes-3 for 3.16" from Kukjin Kim:

Samsung fixes-3 for v3.16
- update the parent for Auudss clock because kernel will be hang
  during late boot if the parent clock is disabled in bootloader.
- enable clk handing in power domain because while power domain
  on/off, its regarding clock source will be reset and it causes
  a problem so need to handle it.
- add mux clocks to be used by power domain for exynos5420-mfc
  during power domain on/off and property in device tree also.
- register cpuidle only for exynos4210 and exynos5250 because a
  system failure will be happened on other exynos SoCs.

* tag 'samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: EXYNOS: Register cpuidle device only on exynos4210 and 5250
  ARM: dts: Add clock property for mfc_pd in exynos5420
  clk: exynos5420: Add IDs for clocks used in PD mfc
  ARM: EXYNOS: Add support for clock handling in power domain
  ARM: dts: Update the parent for Audss clocks in Exynos5420
Signed-off-by: Olof Johansson <olof@lixom.net>

Pull USB fixes from Greg KH:
 "Here are some small USB fixes, PHY driver fixes (they ended up in this
  tree for lack of somewhere else to put them), and some new USB device
  ids"

* tag 'usb-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  phy: omap-usb2: Balance pm_runtime_enable() on probe failure and remove
  phy: core: Fix error path in phy_create()
  drivers: phy: phy-samsung-usb2.c: Add missing MODULE_DEVICE_TABLE
  phy: omap-usb2: fix devm_ioremap_resource error detection code
  phy: sun4i: depend on RESET_CONTROLLER
  USB: serial: ftdi_sio: Add Infineon Triboard
  USB: ftdi_sio: Add extra PID.
  usb: option: Add ID for Telewell TW-LTE 4G v2
  USB: cp210x: add support for Corsair usb dongle

Pull tty/serial fixes from Greg KH:
 "Here are some small serial fixes that resolve some reported problems
  that started in 3.15 with some serial drivers.

  And there's a new dt binding for a serial driver, which was all that
  was needed for the renesas serial driver"

* tag 'tty-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: sh-sci: Add device tree support for r8a7{778,740,3a4} and sh73a0
  serial: imx: Fix build breakage
  serial: arc_uart: Use uart_circ_empty() for open-coded comparison
  serial: Test for no tx data on tx restart

Pull char/misc driver fixes from Greg KH:
 "Here are two hyperv driver fixes, and one i8k driver fix for 3.16"

* tag 'char-misc-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  i8k: Fix non-SMP operation
  Drivers: hv: util: Fix a bug in the KVP code
  Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code

Pull IIO fixes from Greg KH:
 "Here are some IIO driver fixes for 3.16-rc5.  Nothing major, just
  resolves some minor issues that have been reported"

* tag 'staging-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: ti_am335x_adc: Fix: Use same step id at FIFOs both ends
  iio:tcs3472: Check for buffer enabled and locking
  iio: hid-sensor-prox: Fix return values
  iio: hid-sensor-gyro-3d: Fix return values
  iio: hid-sensor-als: Fix return values
  iio: hid-sensor-magn-3d: Fix return values
  iio: hid-sensor-accel-3d: Fix return values
  iio: hid-sensor-press: Fix return values

Fix potential null pointer dereferencing problem caused by e43bb4e6
("ext4: decrement free clusters/inodes counters when block group declared bad")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

This fixes the following lockdep complaint:

[ INFO: possible circular locking dependency detected ]
3.16.0-rc2-mm1+ #7 Tainted: G           O  
-------------------------------------------------------
kworker/u24:0/4356 is trying to acquire lock:
 (&(&sbi->s_es_lru_lock)->rlock){+.+.-.}, at: [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0

but task is already holding lock:
 (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

which lock already depends on the new lock.

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_es_lock);
                               lock(&(&sbi->s_es_lru_lock)->rlock);
                               lock(&ei->i_es_lock);
  lock(&(&sbi->s_es_lru_lock)->rlock);

 *** DEADLOCK ***

6 locks held by kworker/u24:0/4356:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #2:  (&type->s_umount_key#22){++++++}, at: [<ffffffff811a9c74>] grab_super_passive+0x44/0x90
 #3:  (jbd2_handle){+.+...}, at: [<ffffffff812979f9>] start_this_handle+0x189/0x5f0
 #4:  (&ei->i_data_sem){++++..}, at: [<ffffffff81247062>] ext4_map_blocks+0x132/0x550
 #5:  (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

stack backtrace:
CPU: 0 PID: 4356 Comm: kworker/u24:0 Tainted: G           O   3.16.0-rc2-mm1+ #7
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: writeback bdi_writeback_workfn (flush-253:0)
 ffffffff8213dce0 ffff880014b07538 ffffffff815df0bb 0000000000000007
 ffffffff8213e040 ffff880014b07588 ffffffff815db3dd ffff880014b07568
 ffff880014b07610 ffff88003b868930 ffff88003b868908 ffff88003b868930
Call Trace:
 [<ffffffff815df0bb>] dump_stack+0x4e/0x68
 [<ffffffff815db3dd>] print_circular_bug+0x1fb/0x20c
 [<ffffffff810a7a3e>] __lock_acquire+0x163e/0x1d00
 [<ffffffff815e89dc>] ? retint_restore_args+0xe/0xe
 [<ffffffff815ddc7b>] ? __slab_alloc+0x4a8/0x4ce
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff810a8707>] lock_acquire+0x87/0x120
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8128592d>] ? ext4_es_free_extent+0x5d/0x70
 [<ffffffff815e6f09>] _raw_spin_lock+0x39/0x50
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8119760b>] ? kmem_cache_alloc+0x18b/0x1a0
 [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff812869b8>] ext4_es_insert_extent+0xc8/0x180
 [<ffffffff812470f4>] ext4_map_blocks+0x1c4/0x550
 [<ffffffff8124c4c4>] ext4_writepages+0x6d4/0xd00
	...
Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Minchan Kim <minchan@kernel.org>
Cc: stable@vger.kernel.org
Cc: Zheng Liu <gnehzuil.liu@gmail.com>

Dell kernel driver dell-smo8800 provides same freefall interface as hp_accel so
program hpfall.c works also on Dell laptops. So rename it to freefall.c.

Dell driver does not provide hp::hddprotect led so make sure that freefall.c
works also if hp::hddprotect does not exist in sysfs.

Additionally write info to syslog.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Cc: Sonal Santan <sonal.santan@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>