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This patch series fixes compilation problems that were caused by
function naming conflicts between the rtl8192e driver and the
mac80211 stack.
Signed-off-by: George Kadianakis <desnacked at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch fixes compilation problems that were caused by function
naming conflicts between the rtl8187se driver and the mac80211 stack.
Signed-off-by: George Kadianakis <desnacked at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The error tested for is negative
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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For the JR3/PCI cards, the size of the PCIBAR0 region depends on the
number of channels. Don't try and ioremap space for 4 channels if the
card has fewer channels. Also check for ioremap failure.
Thanks to Anders Blomdell for input and Sami Hussein for testing.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The flag COMEDI_CB_BLOCK was marked as "depricated in the header file".
However, this flag is important to wake up the data-reader (and writer)
after new data has arrived from(for) the DAQ card.
Signed-off-by: Bernd Porr <berndporr@f2s.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ringbuffer runs empty
Jan-Matthias Braun spotted a bug which locks up the driver when the
comedi ring buffer runs empty and provided a patch. The driver would
still send the data to comedi but the reader won't wake up any more.
What's required is setting the flag COMEDI_CB_BLOCK after new data has
arrived which wakes up the reader and therefore the read() command.
Signed-off-by: Bernd Porr <berndporr@f2s.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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DST is dead, no one is using it and upstream
has abandoned it, so remove it from the tree because
it is not going anywhere.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Yeeloong netbook has a sm712 video card, need this driver, but it is not
ready to upstream yet, so, go to drivers/staing at first.
This source code is originally from Silicon Motion Technology Corp, and
maintained at http://dev.lemote.com/code/linux_loongson for YeeLoong
netbook. I have done a lot of cleanups for it and merged it into my git
repository at http://dev.lemote.com/code/rt4ls.
Thanks to Simon for testing it on a little-endian x86 platform.
Thanks to Olivier Croset <olivier.croset@actis-computer.com> for
reporting the problem about __BIG_ENDIAN compiling problem and send a
relative patch.
The suspend/resume and blank support are contributed by Jason from
Silicon Motion Technology.
Tested-by: Simon Braunschmidt <sbraun@emlix.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (35 commits)
drm/radeon/kms: add definitions for v4 power tables
drm/radeon/kms: never combine LVDS with another encoder
drm/radeon/kms: Check module arguments to be valid V2
drm/radeon/kms: Avoid crash when trying to cleanup uninitialized structure
drm/radeon/kms: add cvt mode if we only have lvds w/h and no edid (v4)
drm/radeon/kms: add 3DC compression support
drm/radeon/kms: allow rendering while no colorbuffer is set on r300
drm/radeon/kms: enable memory clock reading on legacy (V2)
drm/radeon/kms: prevent parallel AtomBIOS calls
drm/radeon/kms: set proper default tv standard
drm/radeon/kms: fix legacy rmx
drm/radeon/kms/atom: fill in proper defines for digital setup
drm/kms: silencing a false positive warning.
drm/mm: fix logic for selection of best fit block
drm/vmwgfx: Use TTM handles instead of SIDs as user-space surface handles.
drm/vmwgfx: Return -ERESTARTSYS when interrupted by a signal.
drm/vmwgfx: Fix unlocked ioctl and add proper access control
drm/radeon: fix build on 64-bit with some compilers.
drivers/gpu: Use kzalloc for allocating only one thing
DRM: Rename clamp variable
...
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The USB serial code was a new user of the kfifo API, and it was missed
when porting things to the new kfifo API.
Please make the write_fifo in place. Here is my patch to fix the
regression and full ported version.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* korg/drm-radeon-next:
drm/radeon/kms: add definitions for v4 power tables
drm/radeon/kms: never combine LVDS with another encoder
drm/radeon/kms: Check module arguments to be valid V2
drm/radeon/kms: Avoid crash when trying to cleanup uninitialized structure
drm/radeon/kms: add cvt mode if we only have lvds w/h and no edid (v4)
drm/radeon/kms: add 3DC compression support
drm/radeon/kms: allow rendering while no colorbuffer is set on r300
drm/radeon/kms: enable memory clock reading on legacy (V2)
drm/radeon/kms: prevent parallel AtomBIOS calls
drm/radeon/kms: set proper default tv standard
drm/radeon/kms: fix legacy rmx
drm/radeon/kms/atom: fill in proper defines for digital setup
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[airlied: just adding this for completeness to avoid drift between
public atombios.h files]
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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When linking multiple encoders to a connector, make sure
to not link LVDS with another connector. Some bioses
have the same i2c line for LVDS and VGA.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This patch add a function which check module argument to be
valid. On invalid argument it prints a warning and setback
the default value.
V2: Allow 0 for vram limit & agp mode which are the default
value
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Add boolean to record if some part of the driver are initialized or
not this allow to avoid a crash when trying to cleanup uninitialized
structure members.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This fixes LVDS on some mac laptops without a panel edid.
v2 - Set proper mode type flags
v3 - Note that this is not neceesarily the exact panel mode,
but an approximation based on the cvt formula. For these
systems we should ideally read the mode info out of the
registers or add a mode table, but this works and is much
simpler.
v4 - Update comments and debug message.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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There are 2 formats:
ATI1N: 64 bits per 4x4 block, one-channel format
ATI2N: 128 bits per 4x4 block, two-channel format
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Because hardware cannot disable all colorbuffers directly to do depth-only
rendering, a user should:
- disable reading from a colorbuffer in blending
- disable fastfill
- set the color channel mask to 0 to prevent writing to a colorbuffer
Signed-off-by: Dave Airlie <airlied@redhat.com>
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V2: detect IGP cards (which don't have own memory)
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This just adds a mutex around the atombios table execution
so we don't call it from two contexts at once.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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we were just using 1 before.
reported on irc by soreau
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This makes 640x480 on my R100 work again, both
in aspect and centered mode.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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* nouveau/for-airlied:
drm/nouveau: fix bug causing pinned buffers to lose their NO_EVICT flag
drm/nv50: fix suspend/resume delays without firmware present
drm/nouveau: prevent all channel creation if accel not available
drm/nv50: fix two potential suspend/resume oopses
drm/nv40: implement ctxprog/state generation
drm/nv10: Add the initial graph context and soft methods needed for LMA.
drm/nouveau: Fix up buffer eviction, and evict them to GART, if possible.
drm/nouveau: Add proper error handling to nouveau_card_init
drm/nv04: Fix NV04 set_operation software method.
drm/nouveau: Kill global state in BIOS script interpreter
drm/nouveau: Kill global state in NvShadowBIOS
drm/nouveau: use drm debug levels
drm/i2c/ch7006: Fix load detection false positives right after system init.
drm/nv04-nv40: Fix "conflicting memory types" when saving/restoring VGA fonts.
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warning: 'width' may be used uninitialized in this function
drivers/gpu/drm/drm_edid.c
Signed-off-by: Marin Mitov <mitov@issp.bas.bg>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This is from bug 25728.
[airlied: I'm just forwarding the patch for review, Thomas, ickle?]
Acked-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Improve the command verifier to catch all occurences of surface handles,
and translate to SIDs.
This way DMA buffers and 3D surfaces share a common handle space,
which makes it possible for the kms code to differentiate.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Fixes for TTM API change.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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This fixes up vmwgfx for the unlocked ioctl code to avoid
doing it in the driver. Also adds ioctl flags.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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drivers/gpu/drm/radeon/radeon_test.c:45: undefined reference to `__udivdi3'
Reported-by: Mr. James W. Laferriere <babydr@baby-dragons.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Use kzalloc rather than kcalloc(1,...)
The use of the allocated memory that looks like an array is &p->relocs[0],
but this should be the same as p->relocs.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
@@
- kcalloc(1,
+ kzalloc(
...)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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linux/kernel.h has a "clamp" macro, but r300_cmdbuf also uses a variable
with the same name. Right now it doesn't seem to include the header,
but sooner or later someone will. So better rename the variable
now.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
pata_bf54x: handle portmuxing of pins through GPIO PORTs
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM: Runtime PM documentation update
PM / Runtime: Use device type and device class callbacks
PM: Use pm_runtime_put_sync in system resume
PM: Measure device suspend and resume times
PM: Make the initcall_debug style timing for suspend/resume complete
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* git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
jfs: Fix 32bit build warning
Remove obsolete comment in fs.h
Sanitize f_flags helpers
Fix f_flags/f_mode in case of lookup_instantiate_filp() from open(pathname, 3)
anonfd: Allow making anon files read-only
fs/compat_ioctl.c: fix build error when !BLOCK
pohmelfs needs I_LOCK
alloc_file(): simplify handling of mnt_clone_write() errors
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git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb
* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
MAINTAINERS: update entries for WUSB, UWB and WLP subsystems
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git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits)
powerpc/gc/wii: Remove get_irq_desc()
powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock
powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg
powerpc/mpic: Fix problem that affinity is not updated
powerpc/mm: Fix stupid bug in subpge protection handling
powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion
powerpc: Fix MSI support on U4 bridge PCIe slot
powerpc: Handle VSX alignment faults correctly in little-endian mode
powerpc/mm: Fix typo of cpumask_clear_cpu()
powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled.
powerpc: Convert BUG() to use unreachable()
powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible.
powerpc/pseries: Don't panic when H_PROD fails during cpu-online.
powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM
powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs
powerpc/defconfigs: Disable token ring in powerpc defconfigs
powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules
powerpc/pseries: Select XICS and PCI_MSI PSERIES
powerpc/85xx: Wrong variable returned on error
powerpc/iseries: Convert to proc_fops
...
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Fix the cx23888 driver to use the new kfifo API. Using kfifo_reset()
may result in a possible race conditions. This patch fixes it by using
a spinlock around the kfifo_reset() function.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Reviewed-by: Andy Walls <awalls@radix.net>
Acked-by: Andy Walls <awalls@radix.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add kfifo_in_rec() - puts some record data into the FIFO
Add kfifo_out_rec() - gets some record data from the FIFO
Add kfifo_from_user_rec() - puts some data from user space into the FIFO
Add kfifo_to_user_rec() - gets data from the FIFO and write it to user space
Add kfifo_peek_rec() - gets the size of the next FIFO record field
Add kfifo_skip_rec() - skip the next fifo out record
Add kfifo_avail_rec() - determinate the number of bytes available in a record FIFO
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add kfifo_reset_out() for save lockless discard the fifo output
Add kfifo_skip() to skip a number of output bytes
Add kfifo_from_user() to copy user space data into the fifo
Add kfifo_to_user() to copy fifo data to user space
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add DECLARE_KFIFO - macro to declare a kfifo and the associated buffer inside a struct
Add INIT_KFIFO - Initialize a kfifo declared by DECLARED_KFIFO
Add DEFINE_KFIFO - macro to define and initialize a kfifo as a global or local object
Add kfifo_size() - returns the size of the fifo in bytes
Add kfifo_is_empty() - returns true if the fifo is empty
Add kfifo_is_full() - returns true if the fifo is full
Add kfifo_avail() - returns the number of bytes available in the FIFO
Do some code cleanup
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix the "ignoring return value of '...', declared with attribute
warn_unused_result" compiler warning in several users of the new kfifo
API.
It removes the __must_check attribute from kfifo_in() and
kfifo_in_locked() which must not necessary performed.
Fix the allocation bug in the nozomi driver file, by moving out the
kfifo_alloc from the interrupt handler into the probe function.
Fix the kfifo_out() and kfifo_out_locked() users to handle a unexpected
end of fifo.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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rename kfifo_put... into kfifo_in... to prevent miss use of old non in
kernel-tree drivers
ditto for kfifo_get... -> kfifo_out...
Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc
annotations more readable.
Add mini "howto porting to the new API" in kfifo.h
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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change name of __kfifo_* functions to kfifo_*, because the prefix __kfifo
should be reserved for internal functions only.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Move the pointer to the spinlock out of struct kfifo. Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains. Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
- The API is to simple, important functions are missing
- A fifo can be only allocated dynamically
- There is a requirement of a spinlock whether you need it or not
- There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much. The new API has the following benefits:
- Generic usage: For kernel internal use and/or device driver.
- Provide an API for the most use case.
- Slim API: The whole API provides 25 functions.
- Linux style habit.
- DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
- Direct copy_to_user from the fifo and copy_from_user into the fifo.
- The kfifo itself is an in place member of the using data structure, this save an
indirection access and does not waste the kernel allocator.
- Lockless access: if only one reader and one writer is active on the fifo,
which is the common use case, no additional locking is necessary.
- Remove spinlock - give the user the freedom of choice what kind of locking to use if
one is required.
- Ability to handle records. Three type of records are supported:
- Variable length records between 0-255 bytes, with a record size
field of 1 bytes.
- Variable length records between 0-65535 bytes, with a record size
field of 2 bytes.
- Fixed size records, which no record size field.
- Preserve memory resource.
- Performance!
- Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure. This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them. This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Clean up typos/grammos/spellos in events-kmem.txt.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix kernel-doc warnings (@arg name) in string.c::skip_spaces().
Warning(lib/string.c:347): No description found for parameter 'str'
Warning(lib/string.c:347): Excess function parameter 's' description in 'skip_spaces'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This reverts commit 7bc7d637452383d56ba4368d4336b0dde1bb476d, as
requested by John Stultz. Quoting John:
"Petr Titěra reported an issue where he saw odd atime regressions with
2.6.33 where there were a full second worth of nanoseconds in the
nanoseconds field.
He also reviewed the time code and narrowed down the problem: unhandled
overflow of the nanosecond field caused by rounding up the
sub-nanosecond accumulated time.
Details:
* At the end of update_wall_time(), we currently round up the
sub-nanosecond portion of accumulated time when storing it into xtime.
This was added to avoid time inconsistencies caused when the
sub-nanosecond portion was truncated when storing into xtime.
Unfortunately we don't handle the possible second overflow caused by
that rounding.
* Previously the xtime_cache code hid this overflow by normalizing the
xtime value when storing into the xtime_cache.
* We could try to handle the second overflow after the rounding up, but
since this affects the timekeeping's internal state, this would further
complicate the next accumulation cycle, causing small errors in ntp
steering. As much as I'd like to get rid of it, the xtime_cache code is
known to work.
* The correct fix is really to include the sub-nanosecond portion in the
timekeeping accessor function, so we don't need to round up at during
accumulation. This would greatly simplify the accumulation code.
Unfortunately, we can't do this safely until the last three
non-GENERIC_TIME arches (sparc32, arm, cris) are converted (those
patches are in -mm) and we kill off the spots where arches set xtime
directly. This is all 2.6.34 material, so I think reverting the
xtime_cache change is the best approach for now.
Many thanks to Petr for both reporting and finding the issue!"
Reported-by: Petr Titěra <P.Titera@century.cz>
Requested-by: john stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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