- 01 Jun, 2012 16 commits
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Will Deacon authored
As described in commit 07d106d0 ("vfs: fix up ENOIOCTLCMD error handling"), drivers should return -ENOIOCTLCMD if they receive an ioctl command which they don't understand. Doing so will result in -ENOTTY being returned to userspace, which matches the behaviour of the compat layer if it fails to translate an ioctl command. This patch fixes the pipe ioctl to return -ENOIOCTLCMD instead of -EINVAL when passed an unknown ioctl command. Signed-off-by:
Will Deacon <will.deacon@arm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by:
Alan Cox <alan@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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H Hartley Sweeten authored
The init/mount.o source files produce a number of sparse warnings of the type: warning: incorrect type in argument 1 (different address spaces) expected char [noderef] <asn:1>*dev_name got char *name This is due to the syscalls expecting some of the arguments to be user pointers but they are being passed as kernel pointers. This is harmless but adds a lot of noise to a sparse build. To limit the noise just disable the sparse checking in the relevant source files, but still display a warning so that the user knows this has been done. Since the sparse checking has been disabled we can also remove the __user __force casts that are scattered thru the source. Signed-off-by:
H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
Suggest the shorter pr_<level> instead of printk(KERN_<LEVEL>. Prefer to use pr_<level> over bare printks. Prefer to use pr_warn over pr_warning. Signed-off-by:
Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Eric Nelson authored
Requires --strict option during invocation: ~/linux$ scripts/checkpatch --strict foo.patch This tests for a bad habits of mine like this: return 0 ; Note that it does allow a special case of a bare semicolon for empty loops: while (foo()) ; Signed-off-by:
Eric Nelson <eric.nelson@boundarydevices.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Joe Perches <joe@perches.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Denys Vlasenko authored
Previous code was using optimizations which were developed to work well even on narrow-word CPUs (by today's standards). But Linux runs only on 32-bit and wider CPUs. We can use that. First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly divide by 10 much larger numbers, and thus we can print groups of 9 digits instead of groups of 5 digits. Next: there are two algorithms to print larger numbers. One is generic: divide by 1000000000 and repeatedly print groups of (up to) 9 digits. It's conceptually simple, but requires an (unsigned long long) / 1000000000 division. Second algorithm splits 64-bit unsigned long long into 16-bit chunks, manipulates them cleverly and generates groups of 4 decimal digits. It so happens that it does NOT require long long division. If long is > 32 bits, division of 64-bit values is relatively easy, and we will use the first algorithm. If long long is > 64 bits (strange architecture with VERY large long long), second algorithm can't be used, and we again use the first one. Else (if long is 32 bits and long long is 64 bits) we use second one. And third: there is a simple optimization which takes fast path not only for zero as was done before, but for all one-digit numbers. In all tested cases new code is faster than old one, in many cases by 30%, in few cases by more than 50% (for example, on x86-32, conversion of 12345678). Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit case. This patch is based upon an original from Michal Nazarewicz. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by:
Michal Nazarewicz <mina86@mina86.com> Signed-off-by:
Denys Vlasenko <vda.linux@googlemail.com> Cc: Douglas W Jones <jones@cs.uiowa.edu> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Grant Likely authored
The '%p' output of the kernel's vsprintf() uses spec.field_width to determine how many digits to output based on 2 * sizeof(void*) so that all digits of a pointer are shown. ie. a pointer will be output as "001A2B3C" instead of "1A2B3C". However, if the '#' flag is used in the format (%#p), then the code doesn't take into account the width of the '0x' prefix and will end up outputing "0x1A2B3C" instead of "0x001A2B3C". This patch reworks the "pointer()" format hook to include 2 characters for the '0x' prefix if the '#' flag is included. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by:
Grant Likely <grant.likely@secretlab.ca> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nicolas Pitre authored
Signed-off-by:
Nicolas Pitre <nico@linaro.org> Acked-by:
Colin Cross <ccross@android.com> Acked-by:
Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
Use the module-wide pr_fmt() mechanism rather than open-coding "genirq: " everywhere. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Sasikantha babu authored
sethostname() and setdomainname() notify userspace on failure (without modifying uts_kern_table). Change things so that we only notify userspace on success, when uts_kern_table was actually modified. Signed-off-by:
Sasikantha babu <sasikanth.v19@gmail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: WANG Cong <amwang@redhat.com> Reviewed-by:
Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Gustavo Padovan authored
Signed-off-by:
Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Sergei Shtylyov authored
This driver uses PCI_CLASS_REVISION instead of PCI_REVISION_ID, so it wasn't converted by 44c10138 ("PCI: Change all drivers to use pci_device->revision"). In one case, it even reads PCI revision ID without using it -- that code is now removed... Signed-off-by:
Sergei Shtylyov <sshtylyov@ru.mvista.com> Acked-by:
"Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@lsi.com> Cc: Eric Moore <eric.moore@lsi.com> Acked-by:
Auke Kok <auke-jan.h.kok@intel.com> Cc: Greg KH <greg@kroah.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Wei Yang authored
In the comment of allocate_resource(), the explanation of parameter max and min is not correct. Actually, these two parameters are used to specify the range of the resource that will be allocated, not the min/max size that will be allocated. Signed-off-by:
Wei Yang <weiyang@linux.vnet.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Xi Wang authored
ULONG_MAX is often used to check for integer overflow when calculating allocation size. While ULONG_MAX happens to work on most systems, there is no guarantee that `size_t' must be the same size as `long'. This patch introduces SIZE_MAX, the maximum value of `size_t', to improve portability and readability for allocation size validation. Signed-off-by:
Xi Wang <xi.wang@gmail.com> Acked-by:
Alex Elder <elder@dreamhost.com> Cc: David Airlie <airlied@linux.ie> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Xi Wang authored
Add the new kmalloc_array() to the list of general-purpose memory allocators in chapter 14. Signed-off-by:
Xi Wang <xi.wang@gmail.com> Acked-by:
Jesper Juhl <jj@chaosbits.net> Acked-by:
Pekka Enberg <penberg@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Kautuk Consul authored
Commit d065bd81 ("mm: retry page fault when blocking on disk transfer") and commit 37b23e05 ("x86,mm: make pagefault killable") introduced changes into the x86 pagefault handler for making the page fault handler retryable as well as killable. These changes reduce the mmap_sem hold time, which is crucial during OOM killer invocation. Port these changes to um. Signed-off-by:
Kautuk Consul <consul.kautuk@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
This allocation may be large. The code is probing to see if it will succeed and if not, it falls back to vmalloc(). We should suppress any page-allocation failure messages when the fallback happens. Reported-by:
Dave Jones <davej@redhat.com> Acked-by:
David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 29 May, 2012 24 commits
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Sachin Kamat authored
rtc-s3c.c:673:32: warning: `s3c_rtc_drv_data_array' defined but not used [-Wunused-variable] Signed-off-by:
Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Hannu Heikkinen authored
Use the devres managed resource functions in the probe routine. Also affects the remove routine where the previously used free and release functions are not needed. The devm_* functions eliminate the need for manual resource releasing and simplify error handling. Resources allocated by devm_* are freed automatically on driver detach. Signed-off-by:
Hannu Heikkinen <ext-hannu.m.heikkinen@nokia.com> Acked-by:
Stephen Warren <swarren@wwwdotorg.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Rajkumar Kasirajan authored
Remove RTT interrupt handling, since PIE mode interrupts are now better emulated in generic code via an hrtimer we have no need for this, and there is no codepath in the driver that enables these periodic interrupts anyway. Signed-off-by:
Rajkumar Kasirajan <rajkumar.kasirajan@stericsson.com> Signed-off-by:
Linus Walleij <linus.walleij@linaro.org> Cc: Mattias Wallin <mattias.wallin@stericsson.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Roland Stigge authored
Adds device tree support for rtc-lpc32xx.c Signed-off-by:
Roland Stigge <stigge@antcom.de> Acked-by:
Rob Herring <rob.herring@calxeda.com> Acked-by:
Arnd Bergmann <arnd@arndb.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nikolaus Voss authored
If the rtc reports the time might be invalid due to oscillator failure, M41T93_FLAG_OF flag must not be reset by get_time() as the read operation doesn't make the time valid. Without this patch, only the first get_time() reported an invalid time, the second get_time() reported a valid time althought the reported time is probably wrong due to oscillator failure. Instead of resetting in get_time(), with this patch M41T93_FLAG_OF is reset in set_time() when a valid time is to be written. Signed-off-by:
Nikolaus Voss <n.voss@weinmann.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Wolfram Sang authored
Some DS13XX devices have "trickle chargers". Its configuration register is at different locations, the setup is the same, though. Since the configuration is board specific, introduce a platform_data to this driver. Tested with a DS1339 on a custom board. Signed-off-by:
Wolfram Sang <w.sang@pengutronix.de> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Wolfram Sang authored
ds1307 was kzalloced, so no need to zero members of the struct. Signed-off-by:
Wolfram Sang <w.sang@pengutronix.de> Acked-by:
Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Fabio Estevam authored
In order to keep consistency with other rtc drivers,rename CONFIG_RTC_MXC to CONFIG_RTC_DRV_MXC. Signed-off-by:
Fabio Estevam <fabio.estevam@freescale.com> Acked-by:
Wolfram Sang <w.sang@pengutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> [akpm@linux-foundation.org: fix missed arch/arm/configs/imx_v6_v7_defconfig] Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Fabio Estevam authored
RTC_DRV_IMXDI and RTC_MXC are on-chip RTC modules, so move them under "on-CPU RTC drivers" selection menu. While at it change the dependency of RTC_DRV_IMXDI from ARCH_MX25 to SOC_IMX25. Signed-off-by:
Fabio Estevam <fabio.estevam@freescale.com> Acked-by:
Wolfram Sang <w.sang@pengutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Stein authored
Changes are based on arch/cris/arch-v10/drivers/pcf8563.c [akpm@linux-foundation.org: fix sparse warning] Signed-off-by:
Alexander Stein <alexander.stein@systec-electronic.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Mikael Starvik <starvik@axis.com> Acked-by:
Jesper Nilsson <jesper.nilsson@axis.com> Cc: Wu Fengguang <wfg@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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Alexander Stein authored
Currently there is no generic way to get the RTC battery status within an application. So add an ioctl to read the status bit. The idea is that the bit is set once a low voltage is detected. It stays there until it is reset using the RTC_VL_CLR ioctl. Signed-off-by:
Alexander Stein <alexander.stein@systec-electronic.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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H Hartley Sweeten authored
Use module_platform_driver() to remove the boilerplate code. Also, change the probe and remove functions to __devinit/__devexit. Signed-off-by:
H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Viresh Kumar authored
SPEAr platforms now support DT and so must convert all drivers support DT. This patch adds DT probing support for rtc and updates its documentation too. Signed-off-by:
Viresh Kumar <viresh.kumar@st.com> Cc: Stefan Roese <sr@denx.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com> Cc: Rob Herring <robherring2@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Pierre Carrier authored
number()'s behaviour is slighly changed: 0 becomes "0" instead of "00" when using the flag SPECIAL and base 8. Before: Number\Format %o %#o %x %#x 0 0 00 0 0x0 1 1 01 1 0x1 16 20 020 10 0x10 After: Number\Format %o %#o %x %#x 0 0 0 0 0x0 1 1 01 1 0x1 16 20 020 10 0x10 Signed-off-by:
Pierre Carrier <pierre@spotify.com> Acked-by:
Stephen Rothwell <sfr@canb.auug.org.au> Cc: Joe Perches <joe@perches.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nick Piggin authored
We are not preallocating a sufficient number of nodes. Signed-off-by:
Nick Piggin <npiggin@kernel.dk> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Stephen Boyd authored
When a spinlock warning is printed we usually get BUG: spinlock bad magic on CPU#0, modprobe/111 lock: 0xdff09f38, .magic: 00000000, .owner: /0, .owner_cpu: 0 but it's nicer to print the symbol for the lock if we have it so that we can avoid 'grep dff09f38 /proc/kallsyms' to find out which lock it was. Use kallsyms to print the symbol name so we get something a bit easier to read BUG: spinlock bad magic on CPU#0, modprobe/112 lock: test_lock, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 If the lock is not in kallsyms %ps will fall back to printing the address directly. Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Stephen Boyd authored
Using %ps in a printk format will sometimes fail silently and print the empty string if the address passed in does not match a symbol that kallsyms knows about. But using %pS will fall back to printing the full address if kallsyms can't find the symbol. Make %ps act the same as %pS by falling back to printing the address. While we're here also make %ps print the module that a symbol comes from so that it matches what %pS already does. Take this simple function for example (in a module): static void test_printk(void) { int test; pr_info("with pS: %pS\n", &test); pr_info("with ps: %ps\n", &test); } Before this patch: with pS: 0xdff7df44 with ps: After this patch: with pS: 0xdff7df44 with ps: 0xdff7df44 Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
The code comments for bscnl_emit() and bitmap_scnlistprintf() are describing snprintf() return semantics, but these functions use scnprintf() return semantics. Fix that, and document the bitmap_scnprintf() return value as well. Cc: Ryota Ozaki <ozaki.ryota@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
Moving these arrays into static storage shrinks the kernel a bit: text data bss dec hex filename 723 112 64 899 383 lib/string_helpers.o 516 272 64 852 354 lib/string_helpers.o Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Uwe Kleine-König authored
As long as there is no other non-const variable marked __initdata in the same compilation unit it doesn't hurt. If there were one however compilation would fail with error: $variablename causes a section type conflict because a section containing const variables is marked read only and so cannot contain non-const variables. Signed-off-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Chris Metcalf authored
We were bitten by this at one point and added an additional sanity test for DEBUG_LIST. You can't validly add a list_head to a list where either prev or next is the same as the thing you're adding. Signed-off-by:
Chris Metcalf <cmetcalf@tilera.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Johan Hovold authored
Add sub-driver for the LEDs on National Semiconductor / TI LM3533 lighting power chips. The chip provides 256 brightness levels, hardware accelerated blinking as well as ambient-light-sensor and pwm input control. Signed-off-by:
Johan Hovold <jhovold@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Rob Landley <rob@landley.net> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Jonathan Cameron <jic23@cam.ac.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Stein authored
When issuing the following command: for I in 0 1 2 3 4 5 6 7; do echo 0 > /sys/class/leds/pca955x\:${I}/brightness; done It is possible that all the pca955x_read_ls calls are done sequentially before any pca955x_write_ls call is done. This updates the LS only to the last LED update in its set. Fix this by using a global lock for the pca995x device during pca955x_led_work. Also used a struct for shared data betreen all LEDs. [akpm@linux-foundation.org: revert unintentional rename of pca955x_ledsel()] Signed-off-by:
Alexander Stein <alexander.stein@systec-electronic.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Shuah Khan authored
The leds timer trigger does not currently have an interface to activate a one shot timer. The current support allows for setting two timers, one for specifying how long a state to be on, and the second for how long the state to be off. The delay_on value specifies the time period an LED should stay in on state, followed by a delay_off value that specifies how long the LED should stay in off state. The on and off cycle repeats until the trigger gets deactivated. There is no provision for one time activation to implement features that require an on or off state to be held just once and then stay in the original state forever. Without one shot timer interface, user space can still use timer trigger to set a timer to hold a state, however when user space application crashes or goes away without deactivating the timer, the hardware will be left in that state permanently. As a specific example of this use-case, let's look at vibrate feature on phones. Vibrate function on phones is implemented using PWM pins on SoC or PMIC. There is a need to activate one shot timer to control the vibrate feature, to prevent user space crashes leaving the phone in vibrate mode permanently causing the battery to drain. This trigger exports three properties, activate, state, and duration When transient trigger is activated these properties are set to default values. - duration allows setting timer value in msecs. The initial value is 0. - activate allows activating and deactivating the timer specified by duration as needed. The initial and default value is 0. This will allow duration to be set after trigger activation. - state allows user to specify a transient state to be held for the specified duration. Signed-off-by:
Shuah Khan <shuahkhan@gmail.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: NeilBrown <neilb@suse.de> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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