Hi,

On Wed, Feb 8, 2012 at 8:41 PM, Felipe Balbi <balbi@ti.com> wrote:
> Hi guys,
>
> I have just triggered the folllowing:
>
> [   84.860321] ======================================================
> [   84.860321] [ INFO: possible circular locking dependency detected ]
> [   84.860321] 3.3.0-rc2-00026-ge4e8a39 #474 Not tainted
> [   84.860321] -------------------------------------------------------
> [   84.860321] bash/949 is trying to acquire lock:
> [   84.860321]  (sysfs_lock){+.+.+.}, at: [<c0275358>] gpio_value_store+0x24/0xcc
> [   84.860321]
> [   84.860321] but task is already holding lock:
> [   84.860321]  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184
> [   84.911468]
> [   84.911468] which lock already depends on the new lock.
> [   84.911468]
> [   84.920043]
> [   84.920043] the existing dependency chain (in reverse order) is:
> [   84.920043]
> [   84.927886] -> #1 (s_active#22){++++.+}:
> [   84.927886]        [<c008f640>] check_prevs_add+0xdc/0x150
> [   84.927886]        [<c008fc18>] validate_chain.clone.24+0x564/0x694
> [   84.927886]        [<c0090cdc>] __lock_acquire+0x49c/0x980
> [   84.951660]        [<c0091838>] lock_acquire+0x98/0x100
> [   84.951660]        [<c016a8e8>] sysfs_deactivate+0xb0/0x100
> [   84.962982]        [<c016b1b4>] sysfs_addrm_finish+0x2c/0x6c
> [   84.962982]        [<c016b8bc>] sysfs_remove_dir+0x84/0x98
> [   84.962982]        [<c02590d8>] kobject_del+0x10/0x78
> [   84.974670]        [<c02c29e8>] device_del+0x140/0x170
> [   84.974670]        [<c02c2a24>] device_unregister+0xc/0x18
> [   84.985382]        [<c0276894>] gpio_unexport+0xbc/0xdc
> [   84.985382]        [<c02768c8>] gpio_free+0x14/0xfc
> [   85.001708]        [<c0276a28>] unexport_store+0x78/0x8c
> [   85.001708]        [<c02c5af8>] class_attr_store+0x18/0x24
> [   85.007293]        [<c0169990>] sysfs_write_file+0x100/0x184
> [   85.018981]        [<c0109d48>] vfs_write+0xb4/0x148
> [   85.018981]        [<c0109fd0>] sys_write+0x40/0x70
> [   85.018981]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c
> [   85.035003]
> [   85.035003] -> #0 (sysfs_lock){+.+.+.}:
> [   85.035003]        [<c008f54c>] check_prev_add+0x680/0x698
> [   85.035003]        [<c008f640>] check_prevs_add+0xdc/0x150
> [   85.052093]        [<c008fc18>] validate_chain.clone.24+0x564/0x694
> [   85.052093]        [<c0090cdc>] __lock_acquire+0x49c/0x980
> [   85.052093]        [<c0091838>] lock_acquire+0x98/0x100
> [   85.069885]        [<c047e280>] mutex_lock_nested+0x3c/0x2f4
> [   85.069885]        [<c0275358>] gpio_value_store+0x24/0xcc
> [   85.069885]        [<c02c18dc>] dev_attr_store+0x18/0x24
> [   85.087158]        [<c0169990>] sysfs_write_file+0x100/0x184
> [   85.087158]        [<c0109d48>] vfs_write+0xb4/0x148
> [   85.098297]        [<c0109fd0>] sys_write+0x40/0x70
> [   85.098297]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c
> [   85.109069]
> [   85.109069] other info that might help us debug this:
> [   85.109069]
> [   85.117462]  Possible unsafe locking scenario:
> [   85.117462]
> [   85.117462]        CPU0                    CPU1
> [   85.128417]        ----                    ----
> [   85.128417]   lock(s_active#22);
> [   85.128417]                                lock(sysfs_lock);
> [   85.128417]                                lock(s_active#22);
> [   85.142486]   lock(sysfs_lock);
> [   85.151794]
> [   85.151794]  *** DEADLOCK ***
> [   85.151794]
> [   85.151794] 2 locks held by bash/949:
> [   85.158020]  #0:  (&buffer->mutex){+.+.+.}, at: [<c01698b8>] sysfs_write_file+0x28/0x184
> [   85.170349]  #1:  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184
> [   85.170349]
> [   85.178588] stack backtrace:
> [   85.178588] [<c001b824>] (unwind_backtrace+0x0/0xf0) from [<c008de64>] (print_circular_bug+0x100/0x114)
> [   85.193023] [<c008de64>] (print_circular_bug+0x100/0x114) from [<c008f54c>] (check_prev_add+0x680/0x698)
> [   85.193023] [<c008f54c>] (check_prev_add+0x680/0x698) from [<c008f640>] (check_prevs_add+0xdc/0x150)
> [   85.212524] [<c008f640>] (check_prevs_add+0xdc/0x150) from [<c008fc18>] (validate_chain.clone.24+0x564/0x694)
> [   85.212524] [<c008fc18>] (validate_chain.clone.24+0x564/0x694) from [<c0090cdc>] (__lock_acquire+0x49c/0x980)
> [   85.233306] [<c0090cdc>] (__lock_acquire+0x49c/0x980) from [<c0091838>] (lock_acquire+0x98/0x100)
> [   85.233306] [<c0091838>] (lock_acquire+0x98/0x100) from [<c047e280>] (mutex_lock_nested+0x3c/0x2f4)
> [   85.242614] [<c047e280>] (mutex_lock_nested+0x3c/0x2f4) from [<c0275358>] (gpio_value_store+0x24/0xcc)
> [   85.261840] [<c0275358>] (gpio_value_store+0x24/0xcc) from [<c02c18dc>] (dev_attr_store+0x18/0x24)
> [   85.261840] [<c02c18dc>] (dev_attr_store+0x18/0x24) from [<c0169990>] (sysfs_write_file+0x100/0x184)
> [   85.271240] [<c0169990>] (sysfs_write_file+0x100/0x184) from [<c0109d48>] (vfs_write+0xb4/0x148)
> [   85.290008] [<c0109d48>] (vfs_write+0xb4/0x148) from [<c0109fd0>] (sys_write+0x40/0x70)
> [   85.298400] [<c0109fd0>] (sys_write+0x40/0x70) from [<c0013cc0>] (ret_fast_syscall+0x0/0x3c)
> -bash: echo: write error: Operation not permitted
>
> the way to trigger is:
>
> root@legolas:~# cd /sys/class/gpio/
> root@legolas:/sys/class/gpio# echo 2 > export
> root@legolas:/sys/class/gpio# echo 2 > unexport
> root@legolas:/sys/class/gpio# echo 2 > export
> root@legolas:/sys/class/gpio# cd gpio2/
> root@legolas:/sys/class/gpio/gpio2# echo 1 > value

Looks 'sysfs_lock' needn't to be held for unregister, so the patch below may
fix the problem.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The device tps65910/tps65911 supports the sleep
functionality in some of gpios. If gpio is configured
in output mode and sleep is enabled then during device
sleep state, the output of gpio becomes LOW regardless
of non-sleep output value.
Such gpio can be used to control regulator switch such
that output of regulator is off in device sleep state.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

Sodaville has GPIO controller behind the PCI bus. To my suprissed it is
not the same as on PXA.

The interrupt & gpio chip can be referenced from the device tree like
from any other driver. Unfortunately the driver which uses the gpio
interrupt has to use irq_of_parse_and_map() instead of
platform_get_irq(). The problem is that the platform device (which is
created from the device tree) is most likely created before the
interrupt chip is registered and therefore irq_of_parse_and_map() fails.

In theory the driver works as module. In reality most of the irq
functions are not exported to modules and it is possible that _this_
module is unloaded while the provided irqs are still in use.
Signed-off-by: NHans J. Koch <hjk@linutronix.de>
[torbenh@linutronix.de: make it work after the irq namespace cleanup,
	                add some device tree entries.]
Signed-off-by: NTorben Hohn <torbenh@linutronix.de>
[bigeasy@linutronix.de: convert to generic irq & gpio chip]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
[grant.likely@secretlab.ca: depend on x86 to avoid irq_domain breakage]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

we only use the gpio function of mc9s08dz60 mcu chip, so just
add the gpio driver, as this mcu will never be used in other board.
Signed-off-by: NWu Guoxing <b39297@freescale.com>
Reviewed-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Using the correct gpio offset for setting the initial value
of gpio when setting output direction.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This driver does an unconditional read of io space during module init which
causes a bad dereference on ARM.  It looks to me like this is an x86 only
drivers, so restrict it to only compile on x86.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Denis Turischev <denis@compulab.co.il>

The __iomem annotation is to be used together with pointers used
in iowrite32() but not for pointers returned by kzalloc().
For more details see [1] and [2].

This patch will remove the following sparse warning (i.e. when
copiling with "make C=1"):
 * warning: incorrect type in assignment (different address spaces)

References:
[1] A new I/O memory access mechanism (Sep 15, 2004)
    http://lwn.net/Articles/102232/

[2] Being more anal about iospace accesses (Sep 15, 2004)
    http://lwn.net/Articles/102240/Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This patch will remove the following sparse warning ("make C=1"):
 * warning: Using plain integer as NULL pointer
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The __iomem annotation is to be used together with pointers used
as iowrite32() parameter. For more details see [1] and [2].

This patch will remove the following sparse warnings ("make C=1"):
 * warning: incorrect type in assignment (different address spaces)
 * warning: incorrect type in argument 1 (different address spaces)
 * warning: incorrect type in argument 2 (different address spaces)

References:
[1] A new I/O memory access mechanism (Sep 15, 2004)
    http://lwn.net/Articles/102232/

[2] Being more anal about iospace accesses (Sep 15, 2004)
    http://lwn.net/Articles/102240/Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This patch will remove the following sparse warning ("make C=1"):
 * warning: Using plain integer as NULL pointer
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The existing gpio_to_irq() implementation on sa1100 only translates
validly for internal GPIOs.  Since this sub-arch enables GPIOLIB
support, this results in buggy translations for non-internal GPIOs.

Get rid of the private gpio_to_irq() implementation, replacing it
with the .to_irq method in the sa1100 gpio chip instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

STMPE801 is a GPIO expander. GPIO registers for 801 are slightly different from other
variants. This patch adds support for STMPE801 in stmpe gpio driver.
Signed-off-by: NBhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: NPratyush Anand <pratyush.anand@st.com>
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Drivers should not have a dependency on NR_IRQS. Doing so may break with
SPARSE_IRQ enabled. As there are no in kernel users of the pl061 which
have multiple instances with their interrupts combined to a single parent
interrupt, remove this functionality. If this capability is needed later,
it could be supported more cleanly by just using a devicetree property.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Reviewed-by: NViresh Kumar <viresh.kumar@st.com>
Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Acked-by: NBaruch Siach <baruch@tkos.co.il>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>

Convert the pl061 irq_chip code to use the generic irq chip code.

This has the side effect of using 32-bit accesses rather than 8-bit
accesses to interrupt registers. The h/w TRM and testing seem to indicate
this is fine.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

This patch adds 2 functions that allow managed devices to request GPIOs.
These GPIOs will then be managed by drivers/base/devres.c.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

We don't want drivers using NO_IRQ, so remove its use. For now, 0 or
-1 means no irq until platforms are converted to use 0.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.ml.walleij@gmail.com>

Use chained_irq_enter/exit helper functions instead of direct pointer
accesses. This is needed for generic irq chip conversion.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.ml.walleij@gmail.com>

This patch adds the suspend and resume operations in the driver. The patch
ensures the data save and restore for the device registers during the
suspend and resume operations respectively.
Signed-off-by: NDeepak Sikri <deepak.sikri@st.com>
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Acked-by: NBaruch Siach <baruch@tkos.co.il>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This driver will be converted to a dual GPIO + pinctrl driver
since it supports biasing and driving control options. Hopefully
it can serve as an example.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Reimplement a call to devm_request_mem_region followed by a call to ioremap
or ioremap_nocache by a call to devm_request_and_ioremap.

The semantic patch that makes this transformation is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@nm@
expression myname;
identifier i;
@@

struct platform_driver i = { .driver = { .name = myname } };

@@
expression dev,res,size;
expression nm.myname;
@@

-if (!devm_request_mem_region(dev, res->start, size,
-                              \(res->name\|dev_name(dev)\|myname\))) {
-   ...
-   return ...;
-}
... when != res->start
(
-devm_ioremap(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
|
-devm_ioremap_nocache(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
)
... when any
    when != res->start
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

For the human reader.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Where appropriate factor out some boilerplate code for platform device
registration into module_platform_driver. Drivers that don't use the
standard module_init initcall haven't been converted.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Make it easier to follow the by number references into samsung_gpio_cfgs
by putting the indexes into the code initialising the array, improving
readability a bit. Ideally we wouldn't be using magic array indexes at all
but this is easier than coming up with a better way.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

As gpio chips get registered, a device tree node which represents the
gpio chip is searched and attached to it. A translate function is also
provided to convert the gpio specifier into actual platform settings
for pin function selection, pull up/down and driver strength settings.
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
[kgene.kim@samsung.com: fixed build error]
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

The sysdev.h file should not be needed by any in-kernel code, so remove
the .h file from these random files that seem to still want to include
it.

The sysdev code will be going away soon, so this include needs to be
removed no matter what.

Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "Venkatesh Pallipadi
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>

The driver was merged prior to the MFD and won't build with the MFD.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This patch is functionally tested on Samsung SMDKV6410.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid Dajun Chen <dchen@diasemi.com>
Signed-off-by: NAshish Jangam <ashish.jangam@kpitcummins.com>
[grant.likely: don't create an unnecessary header file]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Add a 5121-custom reject if an input-only pin is requested to be output
(see 18.3.1.1 in the refman). Also, rewrite mach-specific quirk setup to
consume less lines which scales better.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
[grant.likely: Fixed build error]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

These hooks will be needed by the general disabl/enable_irq();
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

GPIO's irq action's dev_id is set to the first struct ioh_gpio chip,
so when loop checking the 8 chips, the "chip" should be changed
according.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

In adding DT binding support, the check for NULL platform_data got added
back in inadvertently, so remove it.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

A large chunk of qe_pin_request() is unnecessarily cut-and-paste
directly from of_get_named_gpio_flags().  This patch cuts out the
duplicate code and replaces it with a call to of_get_gpio().

v2: fixed compile error due to missing gpio_to_chip()
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>

This patch adds a kernel message, containing GPIO range and device
name on successful device registration, and removes duplicate messages from the following drivers:
	* gpio-adp5588
	* gpio-bt8xx
	* gpio-cs5535
	* gpio-janz-ttl
	* gpio-nomadik
	* gpio-pcf857x
	* gpio-xilinx
	* drivers/of/gpio.c
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
[grant.likely@secretlab.ca: squashed 2 patches together]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

On October 1 in 2011,
OKI SEMICONDUCTOR Co., Ltd. changed the company name in to LAPIS Semiconductor Co., Ltd.
Signed-off-by: NTomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

ML7831 is companion chip for Intel Atom E6xx series.
Signed-off-by: NTomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

I screwed up by compiling that driver for the machine rather
than the arch. Correcting this fixes the build error.

Cc: Grant Likely <grant.likely@secretlab.ca>
Reported-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit af0c25c4 ("staging: remove obsoleted CS5535/CS5536 GPIO
driver") dropped CS5535_GPIO. So this last reference to CS5535_GPIO has
been an (inconsequential) nop since v3.1. Drop it too.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NDave Martin <dave.martin@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

It's not used outside of the driver so doesn't need to be exported, and
sparse notices this and complains about it.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>