The font methods are console_lock covered. Unfortunately they don't extend
the lock over all the needed tests.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TIOCSERGETLSR should be saved in a uint so the cast here to unsigned
long is a bug.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The following commit: be4b0281
(tty: serial: OMAP: block idle while the UART is transferring data in PIO mode),
is introducing an oops if OMAP is booted using device tree blob because
the pdata will not be initialized.

Check if pdata is set before de-referencing it.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Keyboard struct lifetime is easy, but the locking is not and is completely
ignored by the existing code. Tackle this one head on

- Make the kbd_table private so we can run down all direct users
- Hoick the relevant ioctl handlers into the keyboard layer
- Lock them with the keyboard lock so they don't change mid keypress
- Add helpers for things like console stop/start so we isolate the poking
  around properly
- Tweak the braille console so it still builds

There are a couple of FIXME locking cases left for ioctls that are so hideous
they should be addressed in a later patch. After this patch the kbd_table is
private and all the keyboard jiggery pokery is in one place.

This update fixes speakup and also a memory leak in the original.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver is broken, as reported by Jiri, and to quote Ben:
	Just remove the driver, I don't think anybody cares.
so I'm doing just that here.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

First step to debletcherising the vt console layer - pick a victim and fix
the locking

This is a nice simple object with its own rules so lets pick it out for
treatment. The user of the table already has a lock so we will also use the
same lock for updates.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit a50f724a.

Sasha reported that this causes problems, so revert it.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit d3bda529.

Sasha reported that this causes problems, so revert it.

Cc: Sasha Levin <levinsasha928@gmail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In DMA-operated uart, I found that rx data can be taken by the UART
interrupts during the DMA irq handler. pl011_int is occurred just
before it goes inside spin_lock_irq. When it returns to the callback,
DMA buffer already has been flushed. Then, pl011_dma_rx_chars gets
invalid data. So I add check for the residue as the patch bellow.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Without that fix machines having a s3c2442 CPU have something
  like that in dmesg:
    samsung-uart s3c2440-uart.0: could not find driver data
    samsung-uart s3c2440-uart.1: could not find driver data
    samsung-uart s3c2440-uart.2: could not find driver data
  And serial is never initialized.

The previous log was obtained trough early printk on the gta02
  machine.
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes these build errors:

ERROR: ".udbg_printf" [drivers/tty/ehv_bytechan.ko] undefined!
ERROR: ".register_early_udbg_console" [drivers/tty/ehv_bytechan.ko] undefined!
ERROR: "udbg_putc" [drivers/tty/ehv_bytechan.ko] undefined!

Cc: Timur Tabi <timur@freescale.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Correct spelling "receieve" to "receive" in
drivers/tty/serial/sn_console.c
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/mux.c included 'linux/tty.h' twice, remove
the duplicate.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There are multiple users of this file from different source
paths now, and rather than have ../ paths in include statements,
just move the file to the linux header dir.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is needed to handle the 8250 file merge mess properly for future
patches.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Serial/TTY fixes for the 3.3-rc3 tree

Just a few new device ids, omap serial driver regression fixes, and a
build fix for the 8250 driver movement.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'tty-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: serial: omap-serial: wakeup latency constraint is in microseconds, not milliseconds
  tty: serial: OMAP: block idle while the UART is transferring data in PIO mode
  tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode
  m32r: relocate drivers back out of 8250 dir
  tty: fix a build failure on sparc
  serial: samsung: Add support for EXYNOS5250
  serial: samsung: Add support for EXYNOS4212 and EXYNOS4412
  drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer

Staging tree patches for 3.3-rc3

Big things here is the deletion of the Android pmem driver, as it's
obsolete and no one uses it, the gma500 driver as it's already in the
drm portion of the kernel tree, and the pohmelfs filesystem as it's
obsolete and a rewritten version is being proposed for the fs/ section
of the kernel.

Other than that, a smattering of different bugfixes and regressions, and
some omap drm api merge fixups that were needed due to api changes in
the main portion of the drm tree, allowing this code to build properly
again.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'staging-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (28 commits)
  staging: pohmelfs: remove drivers/staging/pohmelfs
  staging: android/ram_console: Don't build on arches w/o ioremap
  staging: r8712u: Use asynchronous firmware loading
  staging: usbip: fix to prevent potentially using uninitialized spinlock
  staging: r8712u: Fix problem when CONFIG_R8712_AP is set
  staging: tidspbridge: fix incorrect free to drv_datap
  staging: tidspbridge: fix bridge_open memory leaks
  staging: android: lowmemorykiller: Don't wait more than one second for a process to die
  MAINTAINERS: staging: iio: add iio information
  staging: zcache: fix serialization bug in zv stats
  staging: fix go7007-usb license
  Staging: android: binder: Fix crashes when sharing a binder file between processes
  Staging: android: Remove pmem driver
  Staging: asus_oled: fix NULL-ptr crash on unloading
  Staging: asus_oled: fix image processing
  Staging: android: binder: Don't call dump_stack in binder_vma_open
  staging: r8712u: Add new Sitecom UsB ID
  zcache: Set SWIZ_BITS to 8 to reduce tmem bucket lock contention.
  zcache: fix deadlock condition
  staging: drm/omap: fix locking issue
  ...

Driver core fixes for the 3.3-rc3 tree.

A few fixes for kobject warnings that have popped up in the cpu hotplug path,
and a regression fix for the speed of the hotplug memory code.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'driver-core-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver-core: cpu: fix kobject warning when hotplugging a cpu
  ACPI: remove duplicated lines of merging problems with acpi_processor_add
  docbook: fix fatal errors in device-drivers docbook and add DMA Management section
  drivers/base/memory.c: fix memory_dev_init() long delay
  driver core: cpu: remove kernel warning when removing a cpu

Minor char-misc fixes for 3.3-rc3

Nothing big here, some Kconfig fixes for the MISC_DEVICES config option
that was being used incorrectly, and some other minor bug fixes.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mmc: cb710 core: Add missing spin_lock_init for irq_lock of struct cb710_chip
  cs5535-mfgpt: don't call __init function from __devinit
  vmw_balloon: fix for a -Wuninitialized warning
  drivers: misc: Remove MISC_DEVICES config option
  c2port: fix build error for duramar2150 due to missing header.

USB fixes for 3.3-rc3

Here are a few minor USB fixes and a bunch of device id updates for the
USB drivers.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'usb-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: usbserial: add new PID number (0xa951) to the ftdi driver
  usb: ch9.h: usb_endpoint_maxp() uses __le16_to_cpu()
  usb: musb: fix a build error on mips
  uwb & wusb & usb wireless controllers: fix kconfig error & build errors
  usb: Skip PCI USB quirk handling for Netlogic XLP
  powerpc/usb: fix issue of CPU halt when missing USB PHY clock
  usb: otg: mv_otg: Add dependence
  usb: host: Distinguish Kconfig text for Freescale controllers
  USB: add new zte 3g-dongle's pid to option.c
  usb: ch9.h: usb_endpoint_maxp() uses __le16_to_cpu()
  USB: qcserial: don't enable autosuspend
  USB: qcserial: add several new serial devices
  usb: otg: mv_otg: Add dependence
  usb: gadget: zero: fix bug in loopback autoresume handling

The receive FIFO wakeup latency estimate in the omap-serial driver is
three orders of magnitude too small.  This effectively prevents the
MPU from going to a low-power state when CONFIG_CPU_IDLE=y.  This is a
major power management regression and masks some other FIFO-related
bugs in the driver.

Fix by correcting the most egregious problem in the RX wakeup latency
estimate.  There are several other flaws in the estimator; these will
be fixed by a separate patch series intended for 3.4.

The difference in low-power states with this patch can be observed via
debugfs in pm_debug/count.

This estimate does not have any effect when CONFIG_CPU_IDLE=n.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Prevent OMAP UARTs from going idle while they are still transferring
data in PIO mode.  This works around an oversight in the OMAP UART
hardware present in OMAP34xx and earlier: an idle UART won't send a
wakeup when the TX FIFO threshold is reached.  This causes long delays
during data transmission when the MPU powerdomain enters a low-power
mode.  The MPU interrupt controller is not able to respond to
interrupts when it's in a low-power state, so the TX buffer is not
refilled until another wakeup event occurs.

This fix changes the erratum i291 DMA idle workaround.  Rather than
toggling between force-idle and no-idle, it will toggle between
smart-idle and no-idle.  The important part of the workaround is the
no-idle part, so this shouldn't result in any change in behavior.

This fix should work on all OMAP UARTs.  Future patches intended for
the 3.4 merge window will make this workaround conditional on a
"feature" flag, and will use the OMAP36xx+ TX event wakeup support.

Thanks to Kevin Hilman <khilman@ti.com> for mentioning the erratum i291
workaround, which led to the development of this approach.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the (default) PIO mode, use a one-byte RX FIFO threshold.  The OMAP
UART IP blocks do not appear to be capable of waking the system under
an RX timeout condition.  Since the previous RX FIFO threshold was 16
bytes, this meant that omap-serial.c did not become aware of any
received data until all those bytes arrived or until another UART
interrupt occurred.  This made the serial console and presumably other
serial applications (GPS, serial Bluetooth) unusable or extremely
slow.  A 1-byte RX FIFO threshold also allows the MPU to enter a
low-power consumption state while waiting for the FIFO to fill.

This can be verified using the serial console by comparing the
behavior when "0123456789abcde" is pasted in from another window, with
the behavior when "0123456789abcdef" is pasted in.  Since the former
string is less than sixteen bytes long, the string is not echoed for
some time, while the latter string is echoed immediately.

DMA operation is unaffected by this patch.

Thanks to Russell King - ARM Linux <linux@arm.linux.org.uk> for some
additional information on the standard behavior of the RX timeout
event, which was used to improve this commit description.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

_parse_integer() does one or two division instructions (which are slow)
per digit parsed to perform the overflow check.

Furthermore, these are particularly expensive examples of division
instruction as the number of clock cycles required to complete them may
go up with the position of the most significant set bit in the dividend:

	if (*res > div_u64(ULLONG_MAX - val, base))

which is as maximal as possible.

Worse, on 32-bit arches, more than one of these division instructions
may be required per digit.

So, assuming we don't support a base of more than 16, skip the check if the
top nibble of the result is not set at this point.
Signed-off-by: David Howells <dhowells@redhat.com>
[ Changed it to not dereference the pointer all the time - even if the
  compiler can and does optimize it away, the code just looks cleaner.
  And edited the top nybble test slightly to make the code generated on
  x86-64 better in the loop - test against a hoisted constant instead of
  shifting and testing the result ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This allows altera_uart to be used for KGDB debugging over serial line.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function has no users inside the tree and the nios2
(out-of-mainline) port doesn't use it either (anymore).
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There's a real possibility of killing kernel threads that might
have issued use_mm(), so kthread's mm might become non-NULL.

This patch fixes the issue by checking for PF_KTHREAD (just as
get_task_mm()).
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sysrq should grab the tasklist lock, otherwise calling force_sig() is
not safe, as it might race with exiting task, which ->sighand might be
set to NULL already.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

pch_uart_hal_request() has parameters which it never uses, also
it is very short, so merge it with its caller to make code cleaner.
No functional changes at all.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The short get_msr() has some unnecessary code and only used once,
so merge it with its caller to make code cleaner. No functional
change at all.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver will be use as interfaces for multiple kinds of
devices like Bluetooth/GPS etc, this debug hook will make driver
debugging much easier.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

One patch fixes an bug in the ARM/MSM IOMMU code which returned sucess
in the unmap function even when an error occured and the other patch
adds a workaround into the AMD IOMMU driver to better handle broken IVRS
ACPI tables (this patch fixes the case when a device is not listed in
the table but actually translated by the iommu).

* 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/msm: Fix error handling in msm_iommu_unmap()
  iommu/amd: Work around broken IVRS tables

This series contains pending target bug-fixes and cleanups for v3.3-rc3
that have been addressed the past weeks in lio-core.git.

Some of the highlights include:

 - Fix handling for control CDBs with data greater than PAGE_SIZE (andy)
 - Use IP_FREEBIND for iscsi-target to address network portal creation
   issues with systemd (dax)
 - Allow PERSISTENT RESERVE IN for non-reservation holder (marco)
 - Fix iblock se_dev_attrib.unmap_granularity (marco)
 - Fix unsupported WRITE_SAME sense payload handling (martin)
 - Add workaround for zero-length control CDB handling (nab)
 - Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT (nab)
 - Fix target_submit_cmd() exception handling (nab)
 - Return correct ASC for unimplemented VPD pages (roland)
 - Don't zero pages used for data buffers (roland)
 - Fix return code of core_tpg_.*_lun (sebastian)

* '3.3-rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (26 commits)
  target: Fix unsupported WRITE_SAME sense payload
  iscsi: use IP_FREEBIND socket option
  iblock: fix handling of large requests
  target: handle empty string writes in sysfs
  iscsi_target: in_aton needs linux/inet.h
  target: Fix iblock se_dev_attrib.unmap_granularity
  target: Fix target_submit_cmd() exception handling
  target: Change target_submit_cmd() to return void
  target: accept REQUEST_SENSE with 18bytes
  target: Fail INQUIRY commands with EVPD==0 but PAGE CODE!=0
  target: Return correct ASC for unimplemented VPD pages
  iscsi-target: Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT
  target: Allow control CDBs with data > 1 page
  iscsi-target: Fix up a few assignments
  iscsi-target: make one-bit bitfields unsigned
  iscsi-target: Fix double list_add with iscsit_alloc_buffs reject
  iscsi-target: Fix reject release handling in iscsit_free_cmd()
  target: fix return code of core_tpg_.*_lun
  target: use save/restore lock primitive in core_dec_lacl_count()
  target: avoid multiple outputs in scsi_dump_inquiry()
  ...

Some simple md-related fixes.

1/ two small fixes to ensure we handle an interrupted resync properly.
2/ avoid loading the bitmap multiple times in dm-raid

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md: two small fixes to handling interrupt resync.
  Prevent DM RAID from loading bitmap twice.

SPI bug fixes for v3.3-rc2

Minor SPI device driver changes.  A rename of the pch_spi_pcidev symbol
that merely eliminates a modpost warning, and a Kconfig change to allow
the Samsung spi driver to build on EXYNOS.

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  spi-topcliff-pch: rename pch_spi_pcidev to pch_spi_pcidev_driver
  spi: Add spi-s3c64xx driver dependency on ARCH_EXYNOS4

Five fixes

* branch 'akpm':
  pcmcia: fix socket refcount decrementing on each resume
  mm: fix UP THP spin_is_locked BUGs
  drivers/leds/leds-lm3530.c: fix setting pltfm->als_vmax
  mm: compaction: check for overlapping nodes during isolation for migration
  nilfs2: avoid overflowing segment numbers in nilfs_ioctl_clean_segments()

This fixes a memory-corrupting bug: not only does it cause the warning,
but as a result of dropping the refcount to zero, it causes the
pcmcia_socket0 device structure to be freed while it still has
references, causing slab caches corruption.  A fatal oops quickly
follows this warning - often even just a 'dmesg' following the warning
causes the kernel to oops.

While testing suspend/resume on an ARM device with PCMCIA support, and a
CF card inserted, I found that after five suspend and resumes, the
kernel would complain, and shortly die after with slab corruption.

  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()

As the message doesn't give a clue about which kobject, and the built-in
debugging in drivers/base/power/main.c happens too late, this was added
right before each get_device():

  printk("%s: %p [%s] %u\n", __func__, dev, kobject_name(&dev->kobj), atomic_read(&dev->kobj.kref.refcount));

and on the 3rd s2ram cycle, the following behaviour observed:

On the 3rd suspend/resume cycle:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume: c1a0d998 [pcmcia_socket0] 3
  dpm_complete: c1a0d998 [pcmcia_socket0] 2

4th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume: c1a0d998 [pcmcia_socket0] 2
  dpm_complete: c1a0d998 [pcmcia_socket0] 1

5th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume: c1a0d998 [pcmcia_socket0] 1
  dpm_complete: c1a0d998 [pcmcia_socket0] 0
  ------------[ cut here ]------------
  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
  Modules linked in: ucb1x00_core
  Backtrace:
  [<c0212090>] (dump_backtrace+0x0/0x110) from [<c04799dc>] (dump_stack+0x18/0x1c)
  [<c04799c4>] (dump_stack+0x0/0x1c) from [<c021cba0>] (warn_slowpath_common+0x50/0x68)
  [<c021cb50>] (warn_slowpath_common+0x0/0x68) from [<c021cbdc>] (warn_slowpath_null+0x24/0x28)
  [<c021cbb8>] (warn_slowpath_null+0x0/0x28) from [<c0335374>] (kobject_get+0x28/0x50)
  [<c033534c>] (kobject_get+0x0/0x50) from [<c03804f4>] (get_device+0x1c/0x24)
  [<c0388c90>] (dpm_complete+0x0/0x1a0) from [<c0389cc0>] (dpm_resume_end+0x1c/0x20)
  ...

Looking at commit 7b24e798 ("pcmcia: split up central event handler"),
the following change was made to cs.c:

                return 0;
        }
 #endif
-
-       send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
+       if (!(skt->state & SOCKET_CARDBUS) && (skt->callback))
+               skt->callback->early_resume(skt);
        return 0;
 }

And the corresponding change in ds.c is from:

-static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
-{
-       struct pcmcia_socket *s = pcmcia_get_socket(skt);
...
-       switch (event) {
...
-       case CS_EVENT_PM_RESUME:
-               if (verify_cis_cache(skt) != 0) {
-                       dev_dbg(&skt->dev, "cis mismatch - different card\n");
-                       /* first, remove the card */
-                       ds_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
-                       mutex_lock(&s->ops_mutex);
-                       destroy_cis_cache(skt);
-                       kfree(skt->fake_cis);
-                       skt->fake_cis = NULL;
-                       s->functions = 0;
-                       mutex_unlock(&s->ops_mutex);
-                       /* now, add the new card */
-                       ds_event(skt, CS_EVENT_CARD_INSERTION,
-                                CS_EVENT_PRI_LOW);
-               }
-               break;
...
-    }

-    pcmcia_put_socket(s);

-    return 0;
-} /* ds_event */

to:

+static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
+{
+       if (!verify_cis_cache(skt)) {
+               pcmcia_put_socket(skt);
+               return 0;
+       }

+       dev_dbg(&skt->dev, "cis mismatch - different card\n");

+       /* first, remove the card */
+       pcmcia_bus_remove(skt);
+       mutex_lock(&skt->ops_mutex);
+       destroy_cis_cache(skt);
+       kfree(skt->fake_cis);
+       skt->fake_cis = NULL;
+       skt->functions = 0;
+       mutex_unlock(&skt->ops_mutex);

+       /* now, add the new card */
+       pcmcia_bus_add(skt);
+       return 0;
+}

As can be seen, the original function called pcmcia_get_socket() and
pcmcia_put_socket() around the guts, whereas the replacement code
calls pcmcia_put_socket() only in one path.  This creates an imbalance
in the refcounting.

Testing with pcmcia_put_socket() put removed shows that the bug is gone:

  dpm_suspend: c1a10998 [pcmcia_socket0] 5
  dpm_suspend_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume: c1a10998 [pcmcia_socket0] 5
  dpm_complete: c1a10998 [pcmcia_socket0] 5
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>