This is to fix an issue where output will suddenly become very slow.
The problem occurs on 8250 UARTS with the hardware bug UART_BUG_THRE.

BACKGROUND
For normal UARTs (without UART_BUG_THRE): When the serial core layer
gets new transmit data and the transmitter is idle, it buffers the
data and calls the 8250s' serial8250_start_tx() routine which will
simply enable the TX interrupt in the IER register and return. This
should immediately fire a THRE interrupt and begin transmitting the
data.
For buggy UARTs (with UART_BUG_THRE): merely enabling the TX interrupt
in IER does not necessarily generate a new THRE interrupt.
Therefore, a background timer periodically checks to see if there is
pending data, and starts transmission if that is the case.

The bug happens on SMP systems when the system has nothing to transmit,
the transmit interrupt is disabled and the following sequence occurs:
- CPU0: The background timer routine serial8250_backup_timeout()
  starts and saves the state of the interrupt enable register (IER)
  and then disables all interrupts in IER. NOTE: The transmit interrupt
  (TI) bit is saved as disabled.
- CPU1: The serial core gets data to transmit, grabs the port lock and
  calls serial8250_start_tx() which enables the TI in IER.
- CPU0: serial8250_backup_timeout() waits for the port lock.
- CPU1: finishes (with TI enabled) and releases the port lock.
- CPU0: serial8250_backup_timeout() calls the interrupt routine which
  will transmit the next fifo's worth of data and then restores the
  IER from the previously saved value (TI disabled).
At this point, as long as the serial core has more transmit data
buffered, it will not call serial8250_start_tx() again and the
background timer routine will slowly transmit the data.

The fix is to have serial8250_start_tx() get the port lock before
it saves the IER state and release it after restoring IER. This will
prevent serial8250_start_tx() from running in parallel.
Signed-off-by: NAl Cooper <alcooperx@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Data definiton "VendorID=10DB, device_id=800D" is already defined.
This patch deletes the duplicate definition.
Signed-off-by: NTomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds support for the Rosewill RC-305 four-port PCI serial
card, and probably any other four-port serial cards based on the
Moschip MCS9865 chip, assuming that the EEPROM on the card was
programmed in accordance with Table 6 of the MCS9865 EEPROM
Application Note version 0.3 dated 16-May-2008, available from the
Moschip web site (registration required).

This patch is based on an earlier patch [1] for the SYBA 6x serial
port card by Ira W. Snyder.

[1]: http://www.gossamer-threads.com/lists/linux/kernel/1162435Signed-off-by: NEric Smith <eric@brouhaha.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Since commit e0626e38 (spi: prefix modalias with "spi:"),
the spi modalias is prefixed with "spi:".

This patch adds "spi:" prefix and removes "-spi" suffix in the modalias.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

reflect new static uart platform ids introduced by patch
http://article.gmane.org/gmane.linux.kernel/1126105Signed-off-by: NNikolaus Voss <n.voss@weinmann.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

It would have been nice if Intermec had supplied a PNP0501 _CID for the
COM3 device, but they didn't, so we have to recognize it explicitly.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=40612
CC: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: stable <stable@kernel.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/ucc_uart.c: In function 'qe2cpu_addr':
drivers/tty/serial/ucc_uart.c:238:2: warning: format '%x' expects type 'unsigned int', but argument 3 has type 'dma_addr_t'
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently, PCIe bus number is set as fixed value "2".
However, PCIe bus number is not always "2".
This patch sets bus number using probe() parameter.
Signed-off-by: NTomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/samsung.c: In function 's3c24xx_serial_init':
drivers/tty/serial/samsung.c:1237: error: lvalue required as unary '&' operand

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Fix build with DEBUG_PAGEALLOC enabled.

Commit d006199e72a9 ("serial: sh-sci: Regtype probing doesn't need to be
fatal.") made sci_init_single() return when sci_probe_regmap() succeeds,
although it should return when sci_probe_regmap() fails.  This causes
systems using the serial sh-sci driver to crash during boot.

Fix the problem by using the right return condition.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The generic library code already exports the generic function, this was
left-over from the ARM-specific version that just got removed.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 1eb19a12 ("lib/sha1: use the git implementation of
SHA-1"), the ARM SHA1 routines no longer work.  The reason? They
depended on the larger 320-byte workspace, and now the sha1 workspace is
just 16 words (64 bytes).  So the assembly version would overwrite the
stack randomly.

The optimized asm version is also probably slower than the new improved
C version, so there's no reason to keep it around.  At least that was
the case in git, where what appears to be the same assembly language
version was removed two years ago because the optimized C BLK_SHA1 code
was faster.
Reported-and-tested-by: NJoachim Eastwood <manabian@gmail.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

task->cred is declared as __rcu, and access to other tasks' ->cred is,
indeed, protected.  Access to current->cred does not need rcu_dereference()
at all, since only the task itself can change its ->cred.  sparse, of
course, has no way of knowing that...

Add force-cast in current_cred(), make current_fsuid() et.al. use it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Al points out that the do_follow_link() helper function really is
misnamed - it's about whether we should try to follow a symlink or not,
not about actually doing the following.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After commit 3567866b: "RCUify freeing acls, let check_acl() go ahead in
RCU mode if acl is cached" posix_acl_permission is being called with an
unsupported flag and the permission check fails. This patch fixes the issue.
Signed-off-by: NAri Savolainen <ari.m.savolainen@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  ore: Make ore its own module
  exofs: Rename raid engine from exofs/ios.c => ore
  exofs: ios: Move to a per inode components & device-table
  exofs: Move exofs specific osd operations out of ios.c
  exofs: Add offset/length to exofs_get_io_state
  exofs: Fix truncate for the raid-groups case
  exofs: Small cleanup of exofs_fill_super
  exofs: BUG: Avoid sbi realloc
  exofs: Remove pnfs-osd private definitions
  nfs_xdr: Move nfs4_string definition out of #ifdef CONFIG_NFS_V4

The inode structure layout is largely random, and some of the vfs paths
really do care.  The path lookup in particular is already quite D$
intensive, and profiles show that accessing the 'inode->i_op->xyz'
fields is quite costly.

We already optimized the dcache to not unnecessarily load the d_op
structure for members that are often NULL using the DCACHE_OP_xyz bits
in dentry->d_flags, and this does something very similar for the inode
ops that are used during pathname lookup.

It also re-orders the fields so that the fields accessed by 'stat' are
together at the beginning of the inode structure, and roughly in the
order accessed.

The effect of this seems to be in the 1-2% range for an empty kernel
"make -j" run (which is fairly kernel-intensive, mostly in filename
lookup), so it's visible.  The numbers are fairly noisy, though, and
likely depend a lot on exact microarchitecture.  So there's more tuning
to be done.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Gcc tends to generate better code with small integers, including the
DCACHE_xyz flag tests - so move the common ones to be first in the list.
Also just remove the unused DCACHE_INOTIFY_PARENT_WATCHED and
DCACHE_AUTOFS_PENDING values, their users no longer exists in the source
tree.

And add a "unlikely()" to the DCACHE_OP_COMPARE test, since we want the
common case to be a nice straight-line fall-through.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Compute protocol sequence numbers and fragment IDs using MD5.
  crypto: Move md5_transform to lib/md5.c

Export everything from ore need exporting. Change Kbuild and Kconfig
to build ore.ko as an independent module. Import ore from exofs
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

ORE stands for "Objects Raid Engine"

This patch is a mechanical rename of everything that was in ios.c
and its API declaration to an ore.c and an osd_ore.h header. The ore
engine will later be used by the pnfs objects layout driver.

* File ios.c => ore.c

* Declaration of types and API are moved from exofs.h to a new
  osd_ore.h

* All used types are prefixed by ore_ from their exofs_ name.

* Shift includes from exofs.h to osd_ore.h so osd_ore.h is
  independent, include it from exofs.h.

Other than a pure rename there are no other changes. Next patch
will move the ore into it's own module and will export the API
to be used by exofs and later the layout driver
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

Exofs raid engine was saving on memory space by having a single layout-info,
single pid, and a single device-table, global to the filesystem. Then passing
a credential and object_id info at the io_state level, private for each
inode. It would also devise this contraption of rotating the device table
view for each inode->ino to spread out the device usage.

This is not compatible with the pnfs-objects standard, demanding that
each inode can have it's own layout-info, device-table, and each object
component it's own pid, oid and creds.

So: Bring exofs raid engine to be usable for generic pnfs-objects use by:

* Define an exofs_comp structure that holds obj_id and credential info.

* Break up exofs_layout struct to an exofs_components structure that holds a
  possible array of exofs_comp and the array of devices + the size of the
  arrays.

* Add a "comps" parameter to get_io_state() that specifies the ids creds
  and device array to use for each IO.

  This enables to keep the layout global, but the device-table view, creds
  and IDs at the inode level. It only adds two 64bit to each inode, since
  some of these members already existed in another form.

* ios raid engine now access layout-info and comps-info through the passed
  pointers. Everything is pre-prepared by caller for generic access of
  these structures and arrays.

At the exofs Level:

* Super block holds an exofs_components struct that holds the device
  array, previously in layout. The devices there are in device-table
  order. The device-array is twice bigger and repeats the device-table
  twice so now each inode's device array can point to a random device
  and have a round-robin view of the table, making it compatible to
  previous exofs versions.

* Each inode has an exofs_components struct that is initialized at
  load time, with it's own view of the device table IDs and creds.
  When doing IO this gets passed to the io_state together with the
  layout.

While preforming this change. Bugs where found where credentials with the
wrong IDs where used to access the different SB objects (super.c). As well
as some dead code. It was never noticed because the target we use does not
check the credentials.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

ios.c will be moving to an external library, for use by the
objects-layout-driver. Remove from it some exofs specific functions.

Also g_attr_logical_length is used both by inode.c and ios.c
move definition to the later, to keep it independent
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

In future raid code we will need to know the IO offset/length
and if it's a read or write to determine some of the array
sizes we'll need.

So add a new exofs_get_rw_state() API for use when
writeing/reading. All other simple cases are left using the
old way.

The major change to this is that now we need to call
exofs_get_io_state later at inode.c::read_exec and
inode.c::write_exec when we actually know these things. So this
patch is kept separate so I can test things apart from other
changes.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: NDan Kaminsky <dan@doxpara.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to use this for TCP/IP sequence number and fragment ID
generation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  cifs: cope with negative dentries in cifs_get_root
  cifs: convert prefixpath delimiters in cifs_build_path_to_root
  CIFS: Fix missing a decrement of inFlight value
  cifs: demote DFS referral lookup errors to cFYI
  Revert "cifs: advertise the right receive buffer size to the server"

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / Runtime: Allow _put_sync() from interrupts-disabled context
  PM / Domains: Fix pm_genpd_poweron()

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86: (38 commits)
  acer-wmi: support Lenovo ideapad S205 wifi switch
  acerhdf.c: spaces in aliased changed to *
  platform-drivers-x86: ideapad-laptop: add missing ideapad_input_exit in ideapad_acpi_add error path
  x86 driver: fix typo in TDP override enabling
  Platform: fix samsung-laptop DMI identification for N150/N210/220/N230
  dell-wmi: Add keys for Dell XPS L502X
  platform-drivers-x86: samsung-q10: make dmi_check_callback return 1
  Platform: Samsung Q10 backlight driver
  platform-drivers-x86: intel_scu_ipc: convert to DEFINE_PCI_DEVICE_TABLE
  platform-drivers-x86: intel_rar_register: convert to DEFINE_PCI_DEVICE_TABLE
  platform-drivers-x86: intel_menlow: add missing return AE_OK for intel_menlow_register_sensor()
  platform-drivers-x86: intel_mid_thermal: fix memory leak
  platform-drivers-x86: msi-wmi: add missing sparse_keymap_free in msi_wmi_init error path
  Samsung Laptop platform driver: support N510
  asus-wmi: add uwb rfkill support
  asus-wmi: add gps rfkill support
  asus-wmi: add CWAP support and clarify the meaning of WAPF bits
  asus-wmi: return proper value in store_cpufv()
  asus-wmi: check for temp1 presence
  asus-wmi: add thermal sensor
  ...

* 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set
  xen: Fix misleading WARN message at xen_release_chunk
  xen: Fix printk() format in xen/setup.c
  xen/tracing: it looks like we wanted CONFIG_FTRACE
  xen/self-balloon: Add dependency on tmem.
  xen/balloon: Fix compile errors - missing header files.
  xen/grant: Fix compile warning.
  xen/pciback: remove duplicated #include

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  Battery: sysfs_remove_battery(): possible circular locking

Two additional savage4 variants were added, but the S3_SAVAGE4_SERIES
macro was incompletely modified, resulting in a false positive detection
of a savage4 card regardless of which savage card is actually present.

For non-savage4 series cards, such as a Savage/IX-MV card, this results
in garbled video and/or a hard-hang at boot time.  Fix this by changing
an '||' to an '&&' in the S3_SAVAGE4_SERIES macro.
Signed-off-by: NJohn P. Stanley <jpsinthemix@verizon.net>
Reviewed-by: NTormod Volden <debian.tormod@gmail.com>
[ The macros have incomplete parenthesis too, but whatever ..  -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch reviewers now recommend not splitting long user-visible strings,
such as printk messages, even if they exceed 80 columns.  This avoids
breaking grep.  However, that recommendation did not actually appear
anywhere in Documentation/CodingStyle.

See, for example, the thread at
  http://news.gmane.org/find-root.php?message_id=%3c1312215262.11635.15.camel%40Joe%2dLaptop%3eSigned-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The CLOEXE bit is magical, and for performance (and semantic) reasons we
don't actually maintain it in the file descriptor itself, but in a
separate bit array.  Which means that when we show f_flags, the CLOEXE
status is shown incorrectly: we show the status not as it is now, but as
it was when the file was opened.

Fix that by looking up the bit properly in the 'fdt->close_on_exec' bit
array.

Uli needs this in order to re-implement the pfiles program:

  "For normal file descriptors (not sockets) this was the last piece of
   information which wasn't available.  This is all part of my 'give
   Solaris users no reason to not switch' effort.  I intend to offer the
   code to the util-linux-ng maintainers."
Requested-by: NUlrich Drepper <drepper@akkadia.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

WARN_ONCE() is very annoying, in that it shows the stack trace that we
don't care about at all, and also triggers various user-level "kernel
oopsed" logic that we really don't care about.  And it's not like the
user can do anything about the applications (sshd) in question, it's a
distro issue.

Requested-by: Andi Kleen <andi@firstfloor.org> (and many others)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For ChromiumOS, we use SHA-1 to verify the integrity of the root
filesystem.  The speed of the kernel sha-1 implementation has a major
impact on our boot performance.

To improve boot performance, we investigated using the heavily optimized
sha-1 implementation used in git.  With the git sha-1 implementation, we
see a 11.7% improvement in boot time.

10 reboots, remove slowest/fastest.

Before:

  Mean: 6.58 seconds Stdev: 0.14

After (with git sha-1, this patch):

  Mean: 5.89 seconds Stdev: 0.07

The other cool thing about the git SHA-1 implementation is that it only
needs 64 bytes of stack for the workspace while the original kernel
implementation needed 320 bytes.
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Cc: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Cc: Nicolas Pitre <nico@cam.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/sparc/mm/init_64.c:1622:22: error: unused variable '__swapper_4m_tsb_phys_patch_end' [-Werror=unused-variable]
arch/sparc/mm/init_64.c:1621:22: error: unused variable '__swapper_4m_tsb_phys_patch' [-Werror=unused-variable]
Signed-off-by: NDavid S. Miller <davem@davemloft.net>