The locking logic in this function is extremely subtle, and it broke
when we started doing potentially concurrent 'flush_to_ldisc()' calls in
commit e043e42b ("pty: avoid forcing
'low_latency' tty flag").

The code in flush_to_ldisc() used to set 'tty->buf.head' to NULL, with
the intention that this would then cause any other concurrent calls to
not do anything (locking note: we have to drop the buf.lock over the
call to ->receive_buf that can block, which is why we can have
concurrency here at all in the first place).

It also used to set the TTY_FLUSHING bit, which would then cause any
concurrent 'tty_buffer_flush()' to not free all the tty buffers and
clear 'tty->buf.tail'.  And with 'buf.head' being NULL, and 'buf.tail'
being non-NULL, new data would never touch 'buf.head'.

Does that sound a bit too subtle? It was.  If another concurrent call to
'flush_to_ldisc()' were to come in, the NULL buf.head would indeed cause
it to not process the buffer list, but it would still clear TTY_FLUSHING
afterwards, making the buffer protection against 'tty_buffer_flush()' no
longer work.

So this clears it all up.  We depend purely on TTY_FLUSHING for handling
re-entrancy, and stop playing games with the buffer list entirely.  In
fact, the buffer list handling is now robust enough that we could
probably stop doing the whole "protect against 'tty_buffer_flush()'"
thing entirely.

However, Alan also points out that we would probably be better off
simplifying the locking even further, and just take the tty ldisc_mutex
around all the buffer flushing calls.  That seems like a good idea, but
in the meantime this is a conceptually minimal fix (with the patch
itself being bigger than required just to clean the code up and make it
readable).

This fixes keyboard trouble under X:

	http://bugzilla.kernel.org/show_bug.cgi?id=14388Reported-and-tested-by: Frédéric Meunier <fredlwm@gmail.com>
Reported-and-tested-by: Boyan <btanastasov@yahoo.co.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cciss: Add cciss_allow_hpsa module parameter
  cciss: Fix multiple calls to pci_release_regions
  blk-settings: fix function parameter kernel-doc notation
  writeback: kill space in debugfs item name
  writeback: account IO throttling wait as iowait
  elv_iosched_store(): fix strstrip() misuse
  cfq-iosched: avoid probable slice overrun when idling
  cfq-iosched: apply bool value where we return 0/1
  cfq-iosched: fix think time allowed for seekers
  cfq-iosched: fix the slice residual sign
  cfq-iosched: abstract out the 'may this cfqq dispatch' logic
  block: use proper BLK_RW_ASYNC in blk_queue_start_tag()
  block: Seperate read and write statistics of in_flight requests v2
  block: get rid of kblock_schedule_delayed_work()
  cfq-iosched: fix possible problem with jiffies wraparound
  cfq-iosched: fix issue with rq-rq merging and fifo list ordering

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: fix compile warnings

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: revert "save ARCH & CROSS_COMPILE ..."
  warn about use of uninstalled kernel headers
  kbuild: mkcompile_h: trivial cleanups
  kbuild: fix warning when domainname is not available
  kbuild: Fix size_append issue for bzip2/lzma kernel
  kbuild,scripts: use non-builtin echo for '-e'
  kbuild: fix the binrpm-pkg target to work with KBUILD_OUTPUT set

Commit d43c36dc ("headers: remove
sched.h from interrupt.h") left some build errors in some configurations
due to drivers having depended on getting header files "accidentally".
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Combined several one-liners from Ingo into one single patch  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: fix possible deadlock in hidraw_read
  HID: fix kerneldoc comment for hid_input_report()
  HID: add __init/__exit macros to twinhan.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Allow all formats as default for Nvidia HDMI
  ALSA: aaci: ARM1176 aaci-pl041 AC97 register read timeout
  ALSA: hda - Fix volume-knob setup for Dell laptops with STAC9228
  ALSA: hda - Fix mute sound with STAC9227/9228 codecs
  ALSA: bt87x - Add a whitelist for Pinnacle PCTV (11bd:0012)
  ALSA: hda - Fix overflow of spec->init_verbs in patch_realtek.c
  ALSA: ice1724 - Make call to set hw params succeed on ESI Juli@
  ALSA: ice1724: Fix surround on Chaintech AV-710
  ALSA: hda - Add full rates/formats support for Nvidia HDMI

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  ext3: Update documentation about ext3 quota mount options
  ext3: Don't update superblock write time when filesystem is read-only

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
  mfd: Fix twl4030 boot with twl4030 usb transceiver enabled

* git://git.infradead.org/~dwmw2/iommu-2.6.32:
  x86: Move pci_iommu_init to rootfs_initcall()
  Run pci_apply_final_quirks() sooner.
  Mark pci_apply_final_quirks() __init rather than __devinit
  Rename pci_init() to pci_apply_final_quirks(), move it to quirks.c
  intel-iommu: Yet another BIOS workaround: Isoch DMAR unit with no TLB space
  intel-iommu: Decode (and ignore) RHSA entries
  intel-iommu: Make "Unknown DMAR structure" message more informative

In the commit f0613d57
    ALSA: hda - Add full rates/formats support for Nvidia HDMI
the flag LIMITIED_RATE_FMT_SUPPORT was set as default, as I forgot
to clear before commit.

Let's enable all formats/rates as default.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

After a reboot on an ARM1176 which amounts to a softreset, it has been
noted that the ALSA driver does not get registered and the probe fails
with the error "aaci-pl041 fpga:04: ac97 read back fail". In the process
of reading from a register the SL1TxBusy bit is set indicating that the
transceiver is busy and remains so until the default timeout occurs.
Set the Power down register 0x26 to an arbitrary value as specified in
the PL041 manual (page: 3-18) so that AACISL1TX/AACISL2TX registers take
their default state.
Signed-off-by: Philby John <pjohn@in.mvista.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The volume-knob widget needs to be set with 0x7f instead of 0xff
for Dell laptops with STAC9228 codec, too, like the previous commit.

Reference: Novell bnc#545013
	http://bugzilla.novell.com/show_bug.cgi?id=545013Signed-off-by: Takashi Iwai <tiwai@suse.de>

On FSC laptops, the sound gets muted gradually when the volume is chnaged.
This is due to the wrong volume-knob widget setup.  The delta bit (bit 7)
shouldn't be set for these devices.

This patch adds a new quirk to set the value 0x7f to the widget 0x24
instead of 0xff.

Reference: Novell bnc#546006
	http://bugzilla.novell.com/show_bug.cgi?id=546006Signed-off-by: Takashi Iwai <tiwai@suse.de>

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Add cciss_allow_hpsa module parameter.  This parameter causes
the cciss driver to ignore any Smart Array devices known to be
supported by the hpsa driver.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Fix multiple calls to pci_release_regions.  If cciss_pci_init
fails, it already does any necessary call to pci_release_regions,
so this does not need to be done again in cciss_init_one in that
case.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

ALC861-VD lenovo model causes overflow of spec->init_verbs entries due to
the recent changes.  Simply increase the array size to avoid the overflow.
Reported-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Signed-off-by: Jan Kara <jack@suse.cz>

This avoids updating the superblock write time when we are mounting
the root file system read/only but we need to replay the journal; at
that point, for people who are east of GMT and who make their clock
tick in localtime for Windows bug-for-bug compatibility, and this will
cause e2fsck to complain and force a full file system check.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: Prevent AER driver from being loaded on non-root port PCIE devices
  PCI: get larger bridge ranges when space is available
  PCI: pci.c: fix kernel-doc notation
  PCI quirk: TI XIO200a erroneously reports support for fast b2b transfers
  PCI PM: Read device power state from register after updating it
  PCI: remove pci_assign_resource_fixed()
  PCI: PCIe portdrv: remove "-driver" from driver name

* master.kernel.org:/home/rmk/linux-2.6-arm: (24 commits)
  ARM: force dcache flush if dcache_dirty bit set
  [ARM] pxa: workaround errata #37 by not using half turbo switching
  [ARM] pxamci: fix printing gpio numbers in pxamci_probe
  [ARM] pxa/csb726: adjust duplicate structure field initialization
  ARM: Add kmap_atomic type debugging
  ARM: boolean bit testing
  ARM: update die() output
  ARM: Dump code/mem oops lines with the appropriate log level
  ARM: Dump memory and backtrace as one printk per line
  ARM: 5756/1: ep93xx: introduce clk parent
  ARM: 5754/1: ep93xx: update i2c support
  ARM: 5753/1: ep93xx: remove old EP93XX_GPIO_* defines
  ARM: 5729/1: ep93xx: define EP93XX_*_PHYS_BASE with macros
  ARM: 5751/1: ep93xx/micro9: Add Micro9-Slim
  ARM: 5750/1: ep93xx/micro9: Update platform code
  ARM: 5749/1: ep93xx/micro9: Update maintainer
  ARM: 5752/1: SA1100: fix building of h3100
  ARM: 5748/1: bcmring: fix build warning messages
  ARM: 5747/1: Fix the start_pg value in free_memmap()
  ARM: 5746/1: Handle possible translation errors in ARMv6/v7 coherent_user_range
  ...

The MUSB code relies on platform implementations that currently only
exists for Arm and Blackfin processors, so have the MUSB Kconfig depend
upon those arches.

This should prevent other arches from building MUSB via randconfig.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

struct sockaddr_storage * can safely be used as struct sockaddr *.
Suppress an "incompatible pointer type" warning.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 46d57a44 ("serial: use tty_port pointers in the core code")
contained two bugs that causes (rare) crashes:

 - the rename typoed one site

 - a NULL check was missed
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On ARM, update_mmu_cache() does dcache flush for a page only if
it has a kernel mapping (page_mapping(page) != NULL). The correct
behavior would be to force the flush based on dcache_dirty bit only.

One of the cases where present logic would be a problem is when
a RAM based block device[1] is used as a swap disk. In this case,
we would have in-memory data corruption as shown in steps below:

do_swap_page()
{
    - Allocate a new page (if not already in swap cache)
    - Issue read from swap disk
        - Block driver issues flush_dcache_page()
        - flush_dcache_page() simply sets PG_dcache_dirty bit and does not
          actually issue a flush since this page has no user space mapping yet.
    - Now, if swap disk is almost full, this newly read page is removed
      from swap cache and corrsponding swap slot is freed.
    - Map this page anonymously in user space.
    - update_mmu_cache()
        - Since this page does not have kernel mapping (its not in page/swap
          cache and is mapped anonymously), it does not issue dcache flush
          even if dcache_dirty bit is set by flush_dcache_page() above.

    <user now gets stale data since dcache was never flushed>
}

Same problem exists on mips too.

[1] example:
 - brd (RAM based block device)
 - ramzswap (RAM based compressed swap device)
Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

We want this to happen after the PCI quirks, which are now running at
the very end of the fs_initcalls.

This works around the BIOS problems which were originally addressed by
commit db8be50c ('USB: Work around BIOS
bugs by quiescing USB controllers earlier'), which was reverted in
commit d93a8f82.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Having this as a device_initcall() means that some real device drivers
can actually initialise _before_ the quirks are run, which is wrong.

We want it to run _before_ device_initcall(), but _after_ fs_initcall(),
since some arch-specific PCI initialisation like pcibios_assign_resources()
is done at fs_initcall().

We could use rootfs_initcall() but I actually want to use that for the
IOMMU initialisation, which has to come after the quirks, but still
before the real devices. So use fs_initcall_sync() instead -- since this
is entirely synchronous, it doesn't hurt that it'll escape the
synchronisation.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

It doesn't get invoked on hotplug; it can be thrown away after init.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This function may have done more in the past, but all it does now is
apply the PCI_FIXUP_FINAL quirks. So name it sensibly and put it where
it belongs.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The usb regulator supplies (usb1v5, usb1v8 & usb3v1) must be available
before adding the twl4030_usb child, else twl4030_usb_ldo_init() will
always fail thus causing boot lock-up.

This patch fixes boot on OMAP systems using the twl4030 usb transceiver.
CONFIG_TWL4030_USB=y
Signed-off-by: Roger Quadros <ext-roger.quadros@nokia.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

If the loop in hidraw_read() loops more than once, then we might
end up trying to acquire already locked mutex, casuing a deadlock.
Reported-by: iceberg <iceberg@ispras.ru>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Fix the following two compile warnings which show up on i386.

mm/percpu.c:1873: warning: comparison of distinct pointer types lacks a cast
mm/percpu.c:1879: warning: format '%lx' expects type 'long unsigned int', but argument 2 has type 'size_t'
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>

PXA27x Errata #37 implies system will hang when switching into or out of
half turbo (HT bit in CLKCFG) mode, workaround this by not using it.
Signed-off-by: Dennis O'Brien <dennis.obrien@eqware.net>
Cc: stable-2.6.31 <stable@kernel.org>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Reviewed-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

Currently the irq_type field of the csb726_lan_config structure is
initialized twice.  The value in the first case,
SMSC911X_IRQ_POLARITY_ACTIVE_LOW, is normally stored in the irq_polarity
field, so I have renamed the field in the first initialization to that.
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

Fix kernel-doc notation in blk-settings.c::blk_queue_max_discard_sectors().
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This reverts commit db8be50c, as per

	http://bugzilla.kernel.org/show_bug.cgi?id=14374
	http://marc.info/?l=linux-kernel&m=125446885705223&w=4

We simply can't do the USB handoff at FIXUP_HEADER time, since it will
often require us to have valid IO mappings etc.  But that in turn
requires a whole different approach, not this trivial one-liner.

Maybe we could teach all the USB quirk handoff handlers to only do the
quirk if the device has all its registers set up (since if it isn't
initialized, it's unlikely to be active), but regardless that will need
a whole lot more code than just saying "let's do it really early".

The proper fix is almost certainly to just leave the legacy IOMMU
mappings active until after all devices have been initialized.
Reported-by: Nick Piggin <npiggin@suse.de>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>