Add support for pandora (openpandora.org) backlight.
It might look like all this could be done using pwm_bl.c instead, but
there is a need of special programming sequence when turning on the LED
driver chip or else it will misbehave. Doing this using pwm_bl.c would
require to use some register programming and pwm functions from platform
code, and ARM maintainers are allergic to driver-like code in /arch/arm
nowadays. The PMIC PWM driver is currently missing too, so pwm_bl.c
can't be used anyway.
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add backlight driver for Bachmann's ot200 visualisation device. The
driver uses MFGPT 7 of CS5535 silicon to regulate the backlight.
[akpm@linux-foundation.org: remove redundant test of `brightness']
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Andres Salomon <dilinger@queued.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
THis driver supports TI LP8550/LP8551/LP8552/LP8553/LP8556 backlight
devices.
The brightness can be controlled by the I2C or PWM input. The lp855x
driver provides both modes. For the PWM control, pwm-specific functions
can be defined in the platform data. And some information can be read
via the sysfs(lp855x device attributes).
For details, please refer to Documentation/backlight/lp855x-driver.txt.
[axel.lin@gmail.com: add missing mutex_unlock in lp855x_read_byte() error path]
[axel.lin@gmail.com: check platform data in lp855x_probe()]
[axel.lin@gmail.com: small cleanups]
[dan.carpenter@oracle.com: silence a compiler warning]
[axel.lin@gmail.com: use id->driver_data to differentiate lp855x chips]
[akpm@linux-foundation.org: simplify boolean return expression]
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The MCA section included a file referring to Machine Check rather than
Microchannel.
Rename the section to spell out Microchannel and drop the bad file
reference.
Reported-by: Greg Pearson <greg.pearson@hp.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the system is loaded while hotplugging a CPU we might end up with a
bogus hardlockup detection. This has been seen during LTP pounder test
executed in parallel with hotplug test.
The main problem is that enable_watchdog (called when CPU is brought up)
registers perf event which periodically checks per-cpu counter
(hrtimer_interrupts), updated from a hrtimer callback, but the hrtimer
is fired from the kernel thread.
This means that while we already do check for the hard lockup the kernel
thread might be sitting on the runqueue with zillions of tasks so there
is nobody to update the value we rely on and so we KABOOM.
Let's fix this by boosting the watchdog thread priority before we wake
it up rather than when it's already running. This still doesn't handle
a case where we have the same amount of high prio FIFO tasks but that
doesn't seem to be common. The current implementation doesn't handle
that case anyway so this is not worse at least.
Unfortunately, we cannot start perf counter from the watchdog thread
because we could miss a real lock up and also we cannot start the
hrtimer watchdog_enable because we there is no way (at least I don't
know any) to start a hrtimer from a different CPU.
[dzickus@redhat.com: fix compile issue with param]
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I just received another user's pleas for help when their init
mysteriously died. I again explained that they need to check whether it
died because of bad instruction, a segv, or something else. Which was
an annoying detour into writing a trivial C program to spawn his init
and print its exit code:
http://lists.busybox.net/pipermail/busybox/2012-January/077172.html
I hear you saying "just test it under /bin/sh". Well, the crashing init
_was_ /bin/sh.
Which prompted me to make kernel do this first step automatically. We can
print exit code, which makes it possible to see that death was from e.g.
SIGILL without writing test programs.
[akpm@linux-foundation.org: add 0x to hex number output]
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Userspace service managers/supervisors need to track their started
services. Many services daemonize by double-forking and get implicitly
re-parented to PID 1. The service manager will no longer be able to
receive the SIGCHLD signals for them, and is no longer in charge of
reaping the children with wait(). All information about the children is
lost at the moment PID 1 cleans up the re-parented processes.
With this prctl, a service manager process can mark itself as a sort of
'sub-init', able to stay as the parent for all orphaned processes
created by the started services. All SIGCHLD signals will be delivered
to the service manager.
Receiving SIGCHLD and doing wait() is in cases of a service-manager much
preferred over any possible asynchronous notification about specific
PIDs, because the service manager has full access to the child process
data in /proc and the PID can not be re-used until the wait(), the
service-manager itself is in charge of, has happened.
As a side effect, the relevant parent PID information does not get lost
by a double-fork, which results in a more elaborate process tree and
'ps' output:
before:
# ps afx
253 ? Ss 0:00 /bin/dbus-daemon --system --nofork
294 ? Sl 0:00 /usr/libexec/polkit-1/polkitd
328 ? S 0:00 /usr/sbin/modem-manager
608 ? Sl 0:00 /usr/libexec/colord
658 ? Sl 0:00 /usr/libexec/upowerd
819 ? Sl 0:00 /usr/libexec/imsettings-daemon
916 ? Sl 0:00 /usr/libexec/udisks-daemon
917 ? S 0:00 \_ udisks-daemon: not polling any devices
after:
# ps afx
294 ? Ss 0:00 /bin/dbus-daemon --system --nofork
426 ? Sl 0:00 \_ /usr/libexec/polkit-1/polkitd
449 ? S 0:00 \_ /usr/sbin/modem-manager
635 ? Sl 0:00 \_ /usr/libexec/colord
705 ? Sl 0:00 \_ /usr/libexec/upowerd
959 ? Sl 0:00 \_ /usr/libexec/udisks-daemon
960 ? S 0:00 | \_ udisks-daemon: not polling any devices
977 ? Sl 0:00 \_ /usr/libexec/packagekitd
This prctl is orthogonal to PID namespaces. PID namespaces are isolated
from each other, while a service management process usually requires the
services to live in the same namespace, to be able to talk to each
other.
Users of this will be the systemd per-user instance, which provides
init-like functionality for the user's login session and D-Bus, which
activates bus services on-demand. Both need init-like capabilities to
be able to properly keep track of the services they start.
Many thanks to Oleg for several rounds of review and insights.
[akpm@linux-foundation.org: fix comment layout and spelling]
[akpm@linux-foundation.org: add lengthy code comment from Oleg]
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the statement
j->caplist[j->caps].handle = j->caps++;
there is no sequence point between the usage of j->caps on the LHS of
the assignment and the incrementation on its RHS. So it's not defined
in Standard C if j->caps is already incremented when used on the LHS
even though the postfix ++ operator is used. To properly fix that the
incrementation has to be done in a separate expression.
This fixes:
drivers/telephony/ixj.c: In function `add_caps':
drivers/telephony/ixj.c:5930:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5950:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5954:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5965:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5976:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5988:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:5998:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6003:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6008:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6013:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6019:38: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6026:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6031:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6036:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6041:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6049:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6057:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6065:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
drivers/telephony/ixj.c:6071:39: warning: operation on `j->caps' may be undefined [-Wsequence-point]
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Due to the alignment of following variables, these typically consume
more than just the single byte that 'bool' requires, and as there are a
few hundred instances, the cache pollution (not so much the waste of
memory) sums up. Put these variables into their own section, outside of
any half way frequently used memory range.
Do the same also to the __warned variable of rcu_lockdep_assert().
(Don't, however, include the ones used by printk_once() and alike, as
they can potentially be hot.)
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jingoo Han
Grazvydas Ignotas
Christian Gmeiner
Kim, Milo
Julia Lawall
Axel Lin
Wanlong Gao
Joe Perches
Richard Weinberger
Andrew Morton
Michal Hocko
Denys Vlasenko
Lennart Poettering
Uwe Kleine-König
H Hartley Sweeten
Javi Merino
Jan Beulich