Four cpufreq-like governors are provided as examples.
powersave: use the lowest frequency possible. The user (device) should
set the polling_ms as 0 because polling is useless for this governor.
performance: use the highest freqeuncy possible. The user (device)
should set the polling_ms as 0 because polling is useless for this
governor.
userspace: use the user specified frequency stored at
devfreq.user_set_freq. With sysfs support in the following patch, a user
may set the value with the sysfs interface.
simple_ondemand: simplified version of cpufreq's ondemand governor.
When a user updates OPP entries (enable/disable/add), OPP framework
automatically notifies devfreq to update operating frequency
accordingly. Thus, devfreq users (device drivers) do not need to update
devfreq manually with OPP entry updates or set polling_ms for powersave
, performance, userspace, or any other "static" governors.
Note that these are given only as basic examples for governors and any
devices with devfreq may implement their own governors with the drivers
and use them.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Device specific sysfs interface /sys/devices/.../power/devfreq_*
- governor R: name of governor
- cur_freq R: current frequency
- polling_interval R: polling interval in ms given with devfreq profile
W: update polling interval.
- central_polling R: 1 if polling is managed by devfreq framework
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
--
Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++
drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++
2 files changed, 113 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq
With OPPs, a device may have multiple operable frequency and voltage
sets. However, there can be multiple possible operable sets and a system
will need to choose one from them. In order to reduce the power
consumption (by reducing frequency and voltage) without affecting the
performance too much, a Dynamic Voltage and Frequency Scaling (DVFS)
scheme may be used.
This patch introduces the DVFS capability to non-CPU devices with OPPs.
DVFS is a techique whereby the frequency and supplied voltage of a
device is adjusted on-the-fly. DVFS usually sets the frequency as low
as possible with given conditions (such as QoS assurance) and adjusts
voltage according to the chosen frequency in order to reduce power
consumption and heat dissipation.
The generic DVFS for devices, devfreq, may appear quite similar with
/drivers/cpufreq. However, cpufreq does not allow to have multiple
devices registered and is not suitable to have multiple heterogenous
devices with different (but simple) governors.
Normally, DVFS mechanism controls frequency based on the demand for
the device, and then, chooses voltage based on the chosen frequency.
devfreq also controls the frequency based on the governor's frequency
recommendation and let OPP pick up the pair of frequency and voltage
based on the recommended frequency. Then, the chosen OPP is passed to
device driver's "target" callback.
When PM QoS is going to be used with the devfreq device, the device
driver should enable OPPs that are appropriate with the current PM QoS
requests. In order to do so, the device driver may call opp_enable and
opp_disable at the notifier callback of PM QoS so that PM QoS's
update_target() call enables the appropriate OPPs. Note that at least
one of OPPs should be enabled at any time; be careful when there is a
transition.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The CONFIG_ARM_AMBA symbol is selected by the platforms that support
AMBA, and the other platforms (e.g. orion) might not be able to
build that code at all when they do not support the clk API.
Instead, make sure that OC_ETM is only built on platforms that
do support the amba subsystem already.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Some PCI drivers call pcibios_bus_to_resource directly,
but it is only exported when CONFIG_HOTPLUG is set,
because it was initially mean for pccard support.
Moving the export out of the #ifdef lets us avoid these
build errors:
ERROR: "pcibios_bus_to_resource" [drivers/video/vt8623fb.ko] undefined!
ERROR: "pcibios_bus_to_resource" [drivers/video/arkfb.ko] undefined!
ERROR: "pcibios_bus_to_resource" [drivers/video/s3fb.ko] undefined!
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
These functions are used in some PCI drivers with big-endian
MMIO space, and they are trivial to add here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Support for IDE drivers should not be automatic, since most platforms
cannot actually support any IDE low-level drivers. This partly
reverts 2064c946e "ARM: always select HAVE_IDE" to set this symbol
only when either a PC-style bus (PCI, ISA, PCMCIA) is enabled or
a platform is used that is known to have an existing driver in
drivers/ide.
New platforms should not need this option and just use CONFIG_ATA
with drivers/ata/.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Support for the cpu_suspend functions is only built-in
when CONFIG_PM_SLEEP is enabled, but omap3/4, exynos4
and pxa always call cpu_suspend when CONFIG_PM is enabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Distros are starting to ship with toolchains defaulting to
hardfloat. Using such a compiler to build the kernel fails
in the VFP directory with
arch/arm/vfp/entry.S:1:0: sorry, unimplemented: -mfloat-abi=hard and VFP
Adding -mfloat-abi=soft to the gcc command line fixes this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The two functions cpu_is_v6_unaligned and safe_usermode
are only defined when CONFIG_PROC_FS is enabled, but
are used outside of the #ifdef.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Martin <dave.martin@linaro.org>
Thumb2 kernels cannot be built with frame pointers, but can use the
ARM_UNWIND feature for unwinding instead. This makes sure that all
features that rely on unwinding includeing CONFIG_LATENCYTOP and
FAULT_INJECTION_STACKTRACE_FILTER do not enable frame pointers
when the unwinder is already selected, and we always build with
the unwinder when we want a thumb2 kernel, to make sure we do not
get the frame pointers instead.
A different option would be to redefine the CONFIG_FRAME_POINTERS
option on ARM to mean builing with either frame pointers or
the unwinder, and then select which one to use based on the
CPU architecture or another user option. That would still allow
building thumb2 kernels without the unwinder but would also be
more confusing.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The SMP implementation on ARM heavily depends on MMU-only code.
As long as nobody is interested in fixing this, let's disable the
SMP option when building for nommu.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The rtc_lock is used by both the nvram and rtc drivers, so
we need to export it if at least one of the two is built,
not just for the rtc driver.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The omap_dm_timer_remove function gets discarded when
CONFIG_HOTPLUG is not set, so we must not reference it
unconditionally.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* 'irq-urgent-for-linus' of git://tesla.tglx.de/git/linux-2.6-tip:
irq: Fix check for already initialized irq_domain in irq_domain_add
irq: Add declaration of irq_domain_simple_ops to irqdomain.h
* 'x86-urgent-for-linus' of git://tesla.tglx.de/git/linux-2.6-tip:
x86/rtc: Don't recursively acquire rtc_lock
* 'sched-urgent-for-linus' of git://tesla.tglx.de/git/linux-2.6-tip:
posix-cpu-timers: Cure SMP wobbles
sched: Fix up wchan borkage
sched/rt: Migrate equal priority tasks to available CPUs
It is not used outside this driver so no need to make the symbol global.
Also make r852_suspend and r852_resume static.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
My earlier debug log additions added these warnings when compiling 64 bit
kernels:
ath6kl/init.c:962: warning: format '%d' expects type 'int',
but argument 3 has type 'size_t'
ath6kl/init.c:975: warning: format '%d' expects type 'int',
but argument 3 has type 'size_t'
ath6kl/init.c:988: warning: format '%d' expects type 'int',
but argument 3 has type 'size_t'
ath6kl/init.c:1009: warning: format '%d' expects type 'int',
but argument 3 has type 'size_t'
ath6kl/init.c:1192: warning: format '%d' expects type 'int',
but argument 4 has type 'size_t'
ath6kl/init.c:1236: warning: format '%d' expects type 'int',
but argument 4 has type 'size_t'
ath6kl/init.c:1267: warning: format '%d' expects type 'int',
but argument 4 has type 'size_t'
Reported-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
The VDD force bit is turned on before touching the panel, but if it
was enabled, there was no call to turn it back off. Add a call.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Avoid any question about locked registers by just writing the unlock
pattern with every write to the register.
Signed-off-by: Keith Packard <keithp@keithp.com>
Verify that the eDP VDD is on, either with the panel being on or with
the VDD force-on bit being set.
This demonstrates that in many instances, VDD is not on when needed,
which leads to failed EDID communications.
Signed-off-by: Keith Packard <keithp@keithp.com>
We're going to assume that EDID is more reliable than the VBT tables
for eDP panels, which is notably true on MacBook machines where the
VBT contains completely bogus data.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Accesses to the mdio busses must be done with the mdio_lock to ensure
proper operation. Conveniently we have the helper function
mdiobus_read() to do that for us. Lets use it in get_phy_id() instead
of accessing the bus without the lock held.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This masks out all interrupts and ack's any pending ones at IRQ
uninstall time to make sure we don't receive any unexpected interrupts
later on.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We were relying on the BIOS to set these bits, which doesn't always
happen.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The patch enables to register notifier_block for an OPP-device in order
to get notified for any changes in the availability of OPPs of the
device. For example, if a new OPP is inserted or enable/disable status
of an OPP is changed, the notifier is executed.
This enables the usage of opp_add, opp_enable, and opp_disable to
directly take effect with any connected entities such as cpufreq or
devfreq.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch adds board support for the DEVIXP, the MICCPT, and the
MIC256, which are three IXP425 based boards produced by OMICRON
electronics, GmbH.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
802.11 says:
"Sequence numbers for QoS (+)Null frames may be
set to any value."
However, if we use the normal counters then peers
will get confused with aggregation since there'll
be holes in the sequence number sequence.
To avoid that, neither assign a sequence number
to QoS null frames nor put them on aggregation.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
With the addition of uAPSD and driver buffering
the powersave handling has gotten quite complex.
Add a section to the documentation to explain it
for anyone wanting to implement it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
iwlwifi has a separate EOSP notification from
the device, and to make use of that properly
it needs to be passed to mac80211. To be able
to mix with tx_status_irqsafe and rx_irqsafe
it also needs to be an "_irqsafe" version in
the sense that it goes through the tasklet,
the actual flag clearing would be IRQ-safe
but doing it directly would cause reordering
issues.
This is needed in the case of a P2P GO going
into an absence period without transmitting
any frames that should be driver-released as
in this case there's no other way to inform
mac80211 that the service period ended. Note
that for drivers that don't use the _irqsafe
functions another version of this function
will be required.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
iwlwifi needs to know the number of frames that are
going to be sent to a station while it is asleep so
it can properly handle the uCode blocking of that
station.
Before uAPSD, we got by by telling the device that
a single frame was going to be released whenever we
encountered IEEE80211_TX_CTL_POLL_RESPONSE. With
uAPSD, however, that is no longer possible since
there could be more than a single frame.
To support this model, add a new callback to notify
drivers when frames are going to be released.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
My work and some previous work didn't add
all the flags, add them now and while at it
simplify the code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The flaglock in struct sta_info has long been
something that I wanted to get rid of, this
finally does the conversion to atomic bitops.
The conversion itself is straight-forward in
most places, a few things needed to change a
bit since we can no longer use multiple bits
at the same time.
On x86-64, this is a fairly significant code
size reduction:
text data bss dec hex
427861 23648 1008 452517 6e7a5 before
425383 23648 976 450007 6ddd7 after
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If a PS-poll frame is retried (but was received)
there is no way to detect that since it has no
sequence number. As a consequence, the standard
asks us to not react to PS-poll frames until the
response to one made it out (was ACKed or lost).
Implement this by using the WLAN_STA_SP flags to
also indicate a PS-Poll "service period" and the
IEEE80211_TX_STATUS_EOSP flag for the response
packet to indicate the end of the "SP" as usual.
We could use separate flags, but that will most
likely completely confuse drivers, and while the
standard doesn't exclude simultaneously polling
using uAPSD and PS-Poll, doing that seems quite
problematic.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
For PS-poll, there's a possible race between
us expiring a frame and the station polling
for it -- send it a null frame in that case.
For uAPSD, the standard says that we have to
send a frame in each SP, so send null if we
don't have any other frames.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Add uAPSD support to mac80211. This is probably not
possible with all devices, so advertising it with
the cfg80211 flag will be left up to drivers that
want it.
Due to my previous patches it is now a fairly
straight-forward extension. Drivers need to have
accurate TX status reporting for the EOSP frame.
For drivers that buffer themselves, the provided
APIs allow releasing the right number of frames,
but then drivers need to set EOSP and more-data
themselves. This is documented in more detail in
the new code itself.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If there are frames for a station buffered in
the driver, mac80211 announces those in the TIM
IE but there's no way to release them. Add new
API to release such frames and use it when the
station polls for a frame.
Since the API will soon also be used for uAPSD
it is easily extensible.
Note that before this change drivers announcing
driver-buffered frames in the TIM bit actually
will respond to a PS-Poll with a potentially
lower priority frame (if there are any frames
buffered in mac80211), after this patch a driver
that hasn't been changed will no longer respond
at all. This only affects ath9k, which will need
to be fixed to implement the new API.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
It doesn't seem likely, but maybe possible, that the
more-data bit needs to be recomputed due to changes
in the queued frames. Clear it for filtered frames
to ensure that we never send it incorrectly. It'll
be set again as necessary when we retransmit this
frame.
The more likely case is maybe where the station woke
up after the filtered frame in which case more-data
should be clear when the frame is transmitted to the
station since it is now awake.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
