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Commit Graph

144858 Commits

Author SHA1 Message Date
Takashi Iwai
2bf2778e0f ASoC: Optimize switch/case in magician.c
Use default to optimize the switch/case in magicial_playback_hw_params(),
which also fixes the compile warnings below:
  sound/soc/pxa/magician.c:89: warning: 'acds' may be used uninitialized in this function
  sound/soc/pxa/magician.c:89: warning: 'acps' may be used uninitialized in this function

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-05-15 12:20:52 +02:00
Takashi Iwai
2baaec2806 ASoC: Add missing __devexit in wm8940.c
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-05-15 12:18:47 +02:00
Takashi Iwai
5f592bb99b Merge branch 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound-2.6 into topic/asoc 2009-05-15 10:30:21 +02:00
Mark Brown
81a4275bff Merge branch 'for-2.6.30' into for-2.6.31 2009-05-15 08:59:52 +01:00
David Brownell
f492ec9f02 ASoC: DaVinci EVM board support buildfixes
This is a build fix, resyncing the DaVinci EVM ASoC board code
with the version in the DaVinci tree.  That resync includes
support for the DM355 EVM, although that board isn't yet in
mainline.

(NOTE:  also includes a bugfix to the platform_add_resources
call, recently sent by Chaithrika U S <chaithrika@ti.com> but
not yet merged into the DaVinci tree.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-15 08:59:07 +01:00
David Brownell
a62114cb90 ASoC: DaVinci I2S updates
This resyncs the DaVinci I2S code with the version in the DaVinci
tree.  The behavioral change uses updated clock interfaces which
recently merged to mainline.  Two other changes include adding a
comment on the ASP/McBSP/McASP confusion, and dropping pdev->id in
order to support more boards than just the DM644x EVM.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-15 08:58:58 +01:00
David Brownell
82075af6cb ASoC: davinci-pcm buildfixes
This is a buildfix for the DaVinci PCM code, resyncing it with
the version in the DaVinci tree.  The notable change is using
current EDMA interfaces, which recently merged to mainline.
(The older interfaces never made it into mainline.)

NOTE:  open issue, the DMA should be to/from SRAM; see chip
errata for more info.  The artifacts are extremely easy to
hear on DM355 hardware (not yet supported in mainline), but
don't seem as audible on DM6446 hardwaare (which does have
mainline support).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-15 08:58:05 +01:00
Marek Vasut
63c26baa2a ASoC: Support AC97 link off by default on WM9712
The WM9712 can be configured by resistor strapping GPIO4 to behave like
the WM9713 and default to leaving the AC97 link disabled after cold
reset until a warm reset occurs.  In this configuration we need to issue
a warm reset after cold to bring the link up so do so.  The warm reset
will be harmless on systems that don't need it.

[Changelog rewritten to document the reasoning. -- broonie]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 20:52:46 +01:00
Mark Brown
c13cb78ace Merge branch 'pxa2xx-i2s' into for-2.6.31 2009-05-14 20:35:51 +01:00
Karl Beldan
916465a841 ASoC: pxa2xx-i2s: Fix suspend/resume
pxa2xx_i2s_resume is :
 - unconditionnaly setting SACR0_ENB
 - unsetting SACR0_ENB in saved SACR0 pxa_i2s.sacr0
fix these.

In pxa2xx_i2s_{resume,suspend}, save/restore registers even
when !dai->active.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 20:35:32 +01:00
Karl Beldan
9bc04fd167 ASoC: pxa2xx-i2s: Fix inappropriate release of i2s clock
i2s_clk is 'put' for no reason in pxa2xx_i2s_shutdown.
Now we 'get' i2s_clk at probe and 'put' it at driver removal or when
probe fails.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 20:35:31 +01:00
Karl Beldan
34555c1077 ASoC: pxa2xx-i2s: Handle SACR1_DRPL and SACR1_DREC separately
- hw_params enables both RPL and REC functions each time : Enable the
	appropriate function in pxa2xx_i2s_trigger.
- pxa2xx_i2s_shutdown disables i2s anytime one of RPL or REC function is
	off : Turn it off only when both functions are off.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 20:35:23 +01:00
Karl Beldan
b243b77c70 ASoC: pxa2xx-i2s: Proper hw initialization
Make sure we are in a know good state at end of probe :
Reset FIFO logic and registers, and make sure REC and RPL functions
along with FIFO service are disabled (SACR0_RST enables REC and RPL).

Resetting loses current settings so remove reset from stream startup.
Now reset occurs only at probe.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 20:34:40 +01:00
Jon Smirl
d34c430782 ASoC: Add SNDRV_PCM_FMTBIT_S32_BE as a valid AC97 format
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 12:47:33 +01:00
Anuj Aggarwal
14610ce711 ASoC: Added OMAP3 EVM support in ASoC.
Resending the patch after fixing the minor issues.

Signed-off-by: Anuj Aggarwal <anuj.aggarwal@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-14 12:47:26 +01:00
Mark Brown
bb74a6e5c5 ASoC: Point at kernel.org git
The Wolfson git is not currently tracking bleeding edge ASoC so change
to my kernel.org git which is doing so.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-13 19:16:01 +01:00
Karl Beldan
8c10dc4f54 ASoC: pxa2xx-i2s: Proper initialization
Reset FIFO logic and registers, and make sure REC and RPL functions along
with FIFO service are disabled at probe.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-13 19:16:00 +01:00
Takashi Iwai
dd4a416442 Merge branch 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound-2.6 into topic/asoc 2009-05-12 12:32:07 +02:00
Takashi Iwai
ddc4097b77 Merge branch 'topic/drvdata-fix' into topic/asoc 2009-05-12 11:57:09 +02:00
Mark Brown
13e2c86c20 Merge branch 'for-2.6.30' into for-2.6.31 2009-05-12 10:53:33 +01:00
Joonyoung Shim
97b8096dc9 ASoC: TWL4030: change DAPM for analog microphone selection
The inputs of the twl4030 codec can be mixed, so we will use the mixer
DAPM for the analog microphone registers(0x05, 0x06), but if we enable
more than one input at the same time, the input impedance of the input
amplifier will be reduced.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-12 10:53:22 +01:00
Mark Brown
7de0a0aee5 ASoC: Enforce symmetric rates for PXA2xx I2S
There is a single I2S_SYNC pin on the chip.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-12 10:53:22 +01:00
Mike Rapoport
eaaa532883 ASoC: em-x270: make the driver support also eXeda and CM-X300 machines
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-12 10:53:22 +01:00
Greg Kroah-Hartman
ae31c1fbdb sound: remove driver_data direct access of struct device
In the near future, the driver core is going to not allow direct access
to the driver_data pointer in struct device.  Instead, the functions
dev_get_drvdata() and dev_set_drvdata() should be used.  These functions
have been around since the beginning, so are backwards compatible with
all older kernel versions.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-05-12 09:20:54 +02:00
Roel Kluin
31cb31f76e ASoC: remove driver_data direct access of struct device
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-11 22:09:22 +01:00
Mike Rapoport
1ffafeb556 pxa2xx-ac97: fix reset gpio mode setting
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-11 19:01:51 +01:00
Mike Rapoport
914dc18255 ASoC: soc-core: fix crash when removing not instantiated card
If the card was not instantiated in snd_soc_instantiate_card, calling
soc-remove will crash because some of codec, cpu_dai and card .remove
methods are called twice.
Fix this by returning from soc_remove immediately.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-11 19:01:51 +01:00
Mark Brown
151ab22cf7 ASoC: Fix up CODEC DAI formats for big endian CPUs
ASoC uses the standard ALSA data format definitions to specify the wire
format used between the CPU and CODEC. Since the ALSA data formats all
include the endianess of the data but this information is not relevant
by the time the data has been encoded onto the serial link to the CODEC
this means that either all the CODEC drivers need to declare both big and
little endian variants or the core needs to fix up the format constraints
specified by CODEC drivers.

For now take the latter approach - this will need to be revisited if any
CODECs are endianness dependant.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-09 16:35:21 +01:00
Linus Torvalds
091bf7624d Linux 2.6.30-rc5 2009-05-08 17:14:14 -07:00
Linus Torvalds
621c2559c1 Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6:
  mtd: fix timeout in M25P80 driver
  mtd: Bug in m25p80.c during whole-chip erase
  mtd: expose subpage size via sysfs
  mtd: mtd in mtd_release is unused without CONFIG_MTD_CHAR
2009-05-08 17:00:41 -07:00
Linus Torvalds
d9d05fda91 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: MCE: make cmci_discover_lock irq-safe
  x86: xen, i386: reserve Xen pagetables
  x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP
  x86-64: finish cleanup_highmaps()'s job wrt. _brk_end
  x86: fix boot hang in early_reserve_e820()
  x86: Fix a typo in a printk message
  x86, srat: do not register nodes beyond e820 map
2009-05-08 16:59:23 -07:00
Linus Torvalds
825118d1f1 Merge branch 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
* 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  hwmon: (w83781d) Fix W83782D support (NULL pointer dereference)
  hwmon: (asus_atk0110) Fix compiler warning
2009-05-08 16:25:00 -07:00
Linus Torvalds
b20a4e9483 Merge branch 'fixes-for-linus' of git://git.monstr.eu/linux-2.6-microblaze
* 'fixes-for-linus' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Fix return value for sys_ipc
  microblaze: Storage class should be before const qualifier
2009-05-08 16:24:25 -07:00
Masami Hiramatsu
201517a7f3 kprobes: fix to use text_mutex around arm/disarm kprobe
Fix kprobes to lock text_mutex around some arch_arm/disarm_kprobe() which
are newly added by commit de5bd88d5a.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-08 16:23:48 -07:00
Jean Delvare
848ddf116b hwmon: (w83781d) Fix W83782D support (NULL pointer dereference)
Commit 360782dde0 (hwmon: (w83781d) Stop
abusing struct i2c_client for ISA devices) broke W83782D support for
devices connected on the ISA bus. You will hit a NULL pointer
dereference as soon as you read any device attribute. Other devices,
and W83782D devices on the SMBus, aren't affected.

Reported-by: Michel Abraham
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Abraham
2009-05-08 20:27:28 +02:00
Luca Tettamanti
b9008708f2 hwmon: (asus_atk0110) Fix compiler warning
atk_sensor_type is only used when DEBUG is defined.

Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-05-08 20:27:28 +02:00
Sergey Lapin
b4df0a6c9d ASoC: AFEB9260 driver
ASoC driver for AT91SAM9260-based AFEB9260 board

Signed-off-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-08 19:14:34 +01:00
Peter Horton
cd1a6de7d4 mtd: fix timeout in M25P80 driver
Extend erase timeout in M25P80 SPI Flash driver.

The M25P80 drivers fails erasing sectors on a M25P128 because the ready
wait timeout is too short. Change the timeout from a simple loop count to a
suitable number of seconds.

Signed-off-by: Peter Horton <zero@colonel-panic.org>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-08 13:51:53 +01:00
Mark Brown
bec4c99e86 ASoC: Fix file patterns for PXA sound drivers
The file matches for PXA sound drivers missed the generic AC97 support
and were overly specific within sound/soc/pxa, omitting all machine
drivers and the SSP driver.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-08 12:00:13 +01:00
Peter Ujfalusi
c198d81181 ASoC: TWL4030: Fix typo in twl4030_codec_mute function
Copy-paste error: TWL4030_PRECKL_GAIN >> TWL4030_PRECKR_GAIN
It has not caused problems, since
TWL4030_PRECKL_GAIN == TWL4030_PRECKR_GAIN == 0x30

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-05-08 12:00:12 +01:00
Hidetoshi Seto
e5299926d7 x86: MCE: make cmci_discover_lock irq-safe
Lockdep reports the warning below when Li tries to offline one cpu:

[  110.835487] =================================
[  110.835616] [ INFO: inconsistent lock state ]
[  110.835688] 2.6.30-rc4-00336-g8c9ed89 #52
[  110.835757] ---------------------------------
[  110.835828] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
[  110.835908] swapper/0 [HC1[1]:SC0[0]:HE0:SE1] takes:
[  110.835982]  (cmci_discover_lock){?.+...}, at: [<ffffffff80236dc0>] cmci_clear+0x30/0x9b

cmci_clear() can be called via smp_call_function_single().

It is better to disable interrupt while holding cmci_discover_lock,
to turn it into an irq-safe lock - we can deadlock otherwise.

[ Impact: fix possible deadlock in the MCE code ]

Reported-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A03ED38.8000700@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Shaohua Li<shaohua.li@intel.com>
2009-05-08 11:03:26 +02:00
Jeremy Fitzhardinge
33df4db04a x86: xen, i386: reserve Xen pagetables
The Xen pagetables are no longer implicitly reserved as part of the other
i386_start_kernel reservations, so make sure we explicitly reserve them.
This prevents them from being released into the general kernel free page
pool and reused.

[ Impact: fix Xen guest crash ]

Also-Bisected-by: Bryan Donlan <bdonlan@gmail.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EEC.30509@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-08 10:49:11 +02:00
Huang Ying
6407df5ca5 x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP
Tim Starling reported that crashdump will panic with kernel compiled
with CONFIG_KEXEC_JUMP due to null pointer deference in
machine_kexec_32.c: machine_kexec(), when deferencing
kexec_image. Refering to:

http://bugzilla.kernel.org/show_bug.cgi?id=13265

This patch fixes the BUG via replacing global variable reference:
kexec_image in machine_kexec() with local variable reference: image,
which is more appropriate, and will not be null.

Same BUG is in machine_kexec_64.c too, so fixed too in the same way.

[ Impact: fix crash on kexec ]

Reported-by: Tim Starling <tstarling@wikimedia.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1241751101.6259.85.camel@yhuang-dev.sh.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-07 22:01:05 -07:00
Jan Beulich
4983439676 x86-64: finish cleanup_highmaps()'s job wrt. _brk_end
With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.

[ Impact: avoids undesirable TLB aliases ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-07 21:51:34 -07:00
Jan Beulich
6143876651 x86: fix boot hang in early_reserve_e820()
If the first non-reserved (sub-)range doesn't fit the size requested,
an endless loop will be entered. If a range returned from
find_e820_area_size() turns out insufficient in size, the range must
be skipped before calling the function again.

[ Impact: fixes boot hang on some platforms ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-07 21:42:39 -07:00
Linus Torvalds
d7a5926978 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (32 commits)
  [CIFS] Fix double list addition in cifs posix open code
  [CIFS] Allow raw ntlmssp code to be enabled with sec=ntlmssp
  [CIFS] Fix SMB uid in NTLMSSP authenticate request
  [CIFS] NTLMSSP reenabled after move from connect.c to sess.c
  [CIFS] Remove sparse warning
  [CIFS] remove checkpatch warning
  [CIFS] Fix final user of old string conversion code
  [CIFS] remove cifs_strfromUCS_le
  [CIFS] NTLMSSP support moving into new file, old dead code removed
  [CIFS] Fix endian conversion of vcnum field
  [CIFS] Remove trailing whitespace
  [CIFS] Remove sparse endian warnings
  [CIFS] Add remaining ntlmssp flags and standardize field names
  [CIFS] Fix build warning
  cifs: fix length handling in cifs_get_name_from_search_buf
  [CIFS] Remove unneeded QuerySymlink call and fix mapping for unmapped status
  [CIFS] rename cifs_strndup to cifs_strndup_from_ucs
  Added loop check when mounting DFS tree.
  Enable dfs submounts to handle remote referrals.
  [CIFS] Remove older session setup implementation
  ...
2009-05-07 21:13:24 -07:00
Steve French
90e4ee5d31 [CIFS] Fix double list addition in cifs posix open code
Remove adding open file entry twice to lists in the file
Do not fill file info twice in case of posix opens and creates

Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-05-08 03:04:30 +00:00
David Howells
8c9ed899b4 NOMMU: Don't check vm_region::vm_start is page aligned in add_nommu_region()
Don't check vm_region::vm_start is page aligned in add_nommu_region() because
the region may reflect some non-page-aligned mapped file, such as could be
obtained from RomFS XIP.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-07 12:03:41 -07:00
Linus Torvalds
ee7fee0b91 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: remove rd%d links immediately after stopping an array.
  md: remove ability to explicit set an inactive array to 'clean'.
  md: constify VFTs
  md: tidy up status_resync to handle large arrays.
  md: fix some (more) errors with bitmaps on devices larger than 2TB.
  md/raid10: don't clear bitmap during recovery if array will still be degraded.
  md: fix loading of out-of-date bitmap.
2009-05-07 12:01:41 -07:00
Linus Torvalds
8a0a9bd4db random: make get_random_int() more random
It's a really simple patch that basically just open-codes the current
"secure_ip_id()" call, but when open-coding it we now use a _static_
hashing area, so that it gets updated every time.

And to make sure somebody can't just start from the same original seed of
all-zeroes, and then do the "half_md4_transform()" over and over until
they get the same sequence as the kernel has, each iteration also mixes in
the same old "current->pid + jiffies" we used - so we should now have a
regular strong pseudo-number generator, but we also have one that doesn't
have a single seed.

Note: the "pid + jiffies" is just meant to be a tiny tiny bit of noise. It
has no real meaning. It could be anything. I just picked the previous
seed, it's just that now we keep the state in between calls and that will
feed into the next result, and that should make all the difference.

I made that hash be a per-cpu data just to avoid cache-line ping-pong:
having multiple CPU's write to the same data would be fine for randomness,
and add yet another layer of chaos to it, but since get_random_int() is
supposed to be a fast interface I did it that way instead. I considered
using "__raw_get_cpu_var()" to avoid any preemption overhead while still
getting the hash be _mostly_ ping-pong free, but in the end good taste won
out.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-07 11:59:06 -07:00