- 18 Dec, 2012 40 commits
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Oleg Nesterov authored
Add lockdep annotations. Not only this can help to find the potential problems, we do not want the false warnings if, say, the task takes two different percpu_rw_semaphore's for reading. IOW, at least ->rw_sem should not use a single class. This patch exposes this internal lock to lockdep so that it represents the whole percpu_rw_semaphore. This way we do not need to add another "fake" ->lockdep_map and lock_class_key. More importantly, this also makes the output from lockdep much more understandable if it finds the problem. In short, with this patch from lockdep pov percpu_down_read() and percpu_up_read() acquire/release ->rw_sem for reading, this matches the actual semantics. This abuses __up_read() but I hope this is fine and in fact I'd like to have down_read_no_lockdep() as well, percpu_down_read_recursive_readers() will need it. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Anton Arapov <anton@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@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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Oleg Nesterov authored
percpu_rw_semaphore->writer_mutex was only added to simplify the initial rewrite, the only thing it protects is clear_fast_ctr() which otherwise could be called by multiple writers. ->rw_sem is enough to serialize the writers. Kill this mutex and add "atomic_t write_ctr" instead. The writers increment/decrement this counter, the readers check it is zero instead of mutex_is_locked(). Move atomic_add(clear_fast_ctr(), slow_read_ctr) under down_write() to avoid the race with other writers. This is a bit sub-optimal, only the first writer needs this and we do not need to exclude the readers at this stage. But this is simple, we do not want another internal lock until we add more features. And this speeds up the write-contended case. Before this patch the racing writers sleep in synchronize_sched_expedited() sequentially, with this patch multiple synchronize_sched_expedited's can "overlap" with each other. Note: we can do more optimizations, this is only the first step. Signed-off-by:
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Oleg Nesterov authored
Currently the writer does msleep() plus synchronize_sched() 3 times to acquire/release the semaphore, and during this time the readers are blocked completely. Even if the "write" section was not actually started or if it was already finished. With this patch down_write/up_write does synchronize_sched() twice and down_read/up_read are still possible during this time, just they use the slow path. percpu_down_write() first forces the readers to use rw_semaphore and increment the "slow" counter to take the lock for reading, then it takes that rw_semaphore for writing and blocks the readers. Also. With this patch the code relies on the documented behaviour of synchronize_sched(), it doesn't try to pair synchronize_sched() with barrier. Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
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Jan Beulich authored
This is another step towards better standard conformance. Rather than adding a local buffer to store the specified portion of the string (with the need to enforce an arbitrary maximum supported width to limit the buffer size), do a maximum width conversion and then drop as much of it as is necessary to meet the caller's request. Also fail on negative field widths. Uses the deprecated simple_strto*() functions because kstrtoXX() fail on non-zero terminated strings. Signed-off-by:
Jan Beulich <jbeulich@suse.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Andy Shevchenko authored
Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by:
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Andy Shevchenko authored
Signed-off-by:
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Andy Shevchenko authored
[yongjun_wei@trendmicro.com.cn: remove duplicated include] Signed-off-by:
Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by:
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Andy Shevchenko authored
Signed-off-by:
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Andy Shevchenko authored
Remove the custom implementation of the functionality similar to kbasename(). Signed-off-by:
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Andy Shevchenko authored
There are several places in the kernel that use functionality like basename(3) with the exception: in case of '/foo/bar/' we expect to get an empty string. Let's do it common helper for them. Signed-off-by:
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Kim, Milo authored
Signed-off-by:
Milo(Woogyom) Kim <milo.kim@ti.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by:
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Marko Katic authored
Changing backlight intensity on an Akita (Sharp Zaurus C-1000) triggers WARN_ON message: WARNING: at drivers/gpio/gpiolib.c:1672 __gpio_set_value+0x38/0xa4() Modules linked in: Backtrace: corgi_bl_set_intensity+0x0/0x74 corgi_bl_update_status+0x0/0x64 corgi_lcd_probe+0x0/0x258 spi_drv_probe+0x0/0x24 driver_probe_device+0x0/0x208 __driver_attach+0x0/0x94 bus_for_each_dev+0x0/0x90 driver_attach+0x0/0x28 bus_add_driver+0x0/0x22c driver_register+0x0/0x134 spi_register_driver+0x0/0x60 corgi_lcd_driver_init+0x0/0x1c do_one_initcall+0x0/0x174 kernel_init+0x0/0x2a8 Akita machines have backlight controls hooked to a gpio expander chip, max7310 using i2c transfers which can sleep. In this case, pca953x_gpio_set_value() can be called to control gpio, and pca953x_setup_gpio() sets can_sleep flag. Therefore, gpio_set_value_cansleep() should be used in order to avoid WARN_ON on akita machines. Akita is the only exception in this case since other users of corgi_lcd access backlight gpio controls through a different gpio expander which does not set the can_sleep flag. Signed-off-by:Marko Katic <dromede@gmail.com> Signed-off-by:
Jingoo Han <jg1.han@samsung.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by:
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Jingoo Han authored
GPIOF_DIR_OUT and GPIOF_DIR_IN are defined as below: GPIOF_DIR_OUT (0 << 0) GPIOF_DIR_IN (1 << 0) So, when !pdata->reset_inverted is 1, the gpio pin can be set as input, instead of output. To prevent this problem, GPIOF_INIT flag should be used when using devm_gpio_request_one(). Signed-off-by:
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Jingoo Han authored
Previously, when ops functions cannot be called, lcd_show_contrast() and lcd_store_contrast() returned 0, instead of ENXIO. Thus, in this case, a local variable 'rc' for return value should be initialized as ENXIO, after kstrtoul() is called. Signed-off-by:
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Jingoo Han authored
Remove an unnecessary line continuation in pm860x_backlight_probe(). Also, a checkpatch warning is fixed as below: WARNING: Avoid unnecessary line continuations [akpm@linux-foundation.org: remove newline] Signed-off-by:
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Peter Ujfalusi authored
TWL_MODULE_PWM is defined as: #define TWL_MODULE_PWM TWL4030_MODULE_PWM0 Use the common module ID define here which will facilitate the upcoming twl-core cleanup. Signed-off-by:
Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by:
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Thierry Reding authored
This function finds the struct backlight_device for a given device tree node. A dummy function is provided so that it safely compiles out if OF support is disabled. [akpm@linux-foundation.org: Don't use IS_ENABLED(CONFIG_OF)] Signed-off-by:
Thierry Reding <thierry.reding@avionic-design.de> Acked-by:
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Axel Lin authored
We don't need the sysfs file to be world writable or group writable. This file is write-only, change it to S_IWUSR (0200). Signed-off-by:
Axel Lin <axel.lin@ingics.com> Acked-by:
"G.Shark Jeong" <gshark.jeong@gmail.com> Signed-off-by:
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Jingoo Han authored
devm_kfree() allocates memory that is released when a driver detaches. Thus, there is no reason to explicitly call devm_kfree in probe or remove functions. Signed-off-by:
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Jingoo Han authored
devm_kfree() allocates memory that is released when a driver detaches. Thus, there is no reason to explicitly call devm_kfree() in probe or remove functions. Signed-off-by:
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Jingoo Han authored
Remove unnecessary cast of void pointer for platform data in probe function. Signed-off-by:
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Jingoo Han authored
Add 'const' to static array that was missing it in its definition. Also, 'const' is added to ili9320_write_regs(), because it is called by vgg2432a4 driver. Signed-off-by:
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Jingoo Han authored
Add 'const' to static array that was missing it in its definition. Signed-off-by:
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Jingoo Han authored
Add 'const' to static array that was missing it in its definition. Signed-off-by:
Marek Vasut <marex@denx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by:
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Jingoo Han authored
Add 'const' to static array that was missing it in its definition. Signed-off-by:
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Kim, Milo authored
The mutex for accessing lp855x registers is used in case of the user-space interaction. When the brightness is changed via sysfs, the mutex is required. But the backlight class device already provides it. Thus, the lp855x mutex is unnecessary. Signed-off-by:
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Kim, Milo authored
The LP855x family devices support the PWM input for the backlight control. Period of the PWM is configurable in the platform side. Platform specific functions are unnecessary anymore because generic PWM functions are used inside the driver. (PWM input mode) To set the brightness, new lp855x_pwm_ctrl() is used. If a PWM device is not allocated, devm_pwm_get() is called. The PWM consumer name is from the chip name such as 'lp8550' and 'lp8556'. To get the brightness value, no additional handling is required. Just the value of 'props.brightness' is returned. If the PWM driver is not ready while initializing the LP855x driver, it's OK. The PWM device can be retrieved later, when the brightness value is changed. Documentation is updated with an example. [akpm@linux-foundation.org: coding-style simplification, per Thierry] Signed-off-by:
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Jingoo Han authored
By using devm_gpio_request_one it is possible to set the direction and initial value in one shot. Thus, using devm_gpio_request_one can make the code simpler. Signed-off-by:
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Jingoo Han authored
By using devm_gpio_request_one it is possible to set the direction and initial value in one shot. Thus, using devm_gpio_request_one can make the code simpler. Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: WARNING: please, no space before tabs Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch error and warning as below: ERROR: spaces required around that '?' (ctx:VxW) ERROR: space required after that ',' (ctx:VxV) Also, unnecessary lines are removed. Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: WARNING: please, no space before tabs Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch error as below: ERROR: spaces prohibited around that ':' (ctx:WxW) Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: WARNING: please, no spaces at the start of a line Also, long comments are fixed for the preferred style. Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: ERROR: inline keyword should sit between storage class and type Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: WARNING: static const char * array should probably be static const char * const Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch warning as below: WARNING: please, no space before tabs Also, unnecessary line is removed. Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch error and warning as below: ERROR: return is not a function, parentheses are not required Also, long comments are fixed for the preferred style. Signed-off-by:
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Jingoo Han authored
This patch fixes the checkpatch error and warning as below: WARNING: please, no space before tabs WARNING: please, no spaces at the start of a line WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable WARNING: braces {} are not necessary for single statement blocks ERROR: code indent should use tabs where possible Signed-off-by: -
Jingoo Han authored
This patch fixes the checkpatch error and warning as below: WARNING: please, no space before tabs WARNING: please, no spaces at the start of a line ERROR: do not initialise statics to 0 or NULL ERROR: code indent should use tabs where possible Signed-off-by:
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