Tejun writes:
Hello, Jens.
Please consider pulling from the following branch to receive cfq blkcg
hierarchy support. The branch is based on top of v3.8-rc2.
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git blkcg-cfq-hierarchy
The patchset was reviewd in the following thread.
http://thread.gmane.org/gmane.linux.kernel.cgroups/5571
[Issue]
When pstore is in panic and emergency-restart paths, it may be blocked
in those paths because it simply takes spin_lock.
This is an example scenario which pstore may hang up in a panic path:
- cpuA grabs psinfo->buf_lock
- cpuB panics and calls smp_send_stop
- smp_send_stop sends IRQ to cpuA
- after 1 second, cpuB gives up on cpuA and sends an NMI instead
- cpuA is now in an NMI handler while still holding buf_lock
- cpuB is deadlocked
This case may happen if a firmware has a bug and
cpuA is stuck talking with it more than one second.
Also, this is a similar scenario in an emergency-restart path:
- cpuA grabs psinfo->buf_lock and stucks in a firmware
- cpuB kicks emergency-restart via either sysrq-b or hangcheck timer.
And then, cpuB is deadlocked by taking psinfo->buf_lock again.
[Solution]
This patch avoids the deadlocking issues in both panic and emergency_restart
paths by introducing a function, is_non_blocking_path(), to check if a cpu
can be blocked in current path.
With this patch, pstore is not blocked even if another cpu has
taken a spin_lock, in those paths by changing from spin_lock_irqsave
to spin_trylock_irqsave.
In addition, according to a comment of emergency_restart() in kernel/sys.c,
spin_lock shouldn't be taken in an emergency_restart path to avoid
deadlock. This patch fits the comment below.
<snip>
/**
* emergency_restart - reboot the system
*
* Without shutting down any hardware or taking any locks
* reboot the system. This is called when we know we are in
* trouble so this is our best effort to reboot. This is
* safe to call in interrupt context.
*/
void emergency_restart(void)
<snip>
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
In commit 975927b942c932,it add blk_rq_pos to sort rq when flushing.
Although this commit was used for the situation which blk_plug handled
multi devices on the same time like md device.
I think there must be some situations like this but only single
device.
So remove the should_sort judgement.
Because the parameter should_sort is only for this purpose,it can delete
should_sort from blk_plug.
CC: Shaohua Li <shli@kernel.org>
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch elevator to use the new hashtable implementation. This reduces the
amount of generic unrelated code in the elevator.
This also removes the dymanic allocation of the hash table. The size of the table is
constant so there's no point in paying the price of an extra dereference when accessing
it.
This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is a cosmetic patch only. Comparison of the resulting binary showed
only line number differences.
This patch does not affect the generation of the Linux binary.
This patch decreases 44 lines of 20121114 divergence.diff.
There are naming conflicts between Linux and ACPICA on table handlers. This
patch cleans up this conflicts to reduce the source code diff between Linux
and ACPICA.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch makes it so that we can support transmit packet steering without
sysfs needing to be enabled. The reason for making this change is to make
it so that a driver can make use of the XPS even while the sysfs portion of
the interface is not present.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds two functions, netif_reset_xps_queue and
netif_set_xps_queue. The main idea behind these two functions is to
provide a mechanism through which drivers can update their defaults in
regards to XPS.
Currently no such mechanism exists and as a result we cannot use XPS for
things such as ATR which would require a basic configuration to start in
which the Tx queues are mapped to CPUs via a 1:1 mapping. With this change
I am making it possible for drivers such as ixgbe to be able to use the XPS
feature by controlling the default configuration.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change splits the core bits of netdev_pick_tx into a separate function.
The main idea behind this is to make this code accessible to select queue
functions when they decide to process the standard path instead of their
own custom path in their select queue routine.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that all in-kernel users of __dev* are gone, let's remove them from
init.h to keep them from popping up again and again.
Thanks to Bill Pemberton for doing all of the hard work to make removal
of this possible.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 'acpi-scan' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / scan: Treat power resources in a special way
ACPI: Remove unused struct acpi_pci_root.id member
ACPI: Drop ACPI device .bind() and .unbind() callbacks
ACPI / PCI: Move the _PRT setup and cleanup code to pci-acpi.c
ACPI / PCI: Rework the setup and cleanup of device wakeup
ACPI: Add .setup() and .cleanup() callbacks to struct acpi_bus_type
ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argument
ACPI: Replace ACPI device add_type field with a match_driver flag
ACPI: Drop the second argument of acpi_bus_scan()
ACPI: Remove the arguments of acpi_bus_add() that are not used
ACPI: Remove acpi_start_single_object() and acpi_bus_start()
ACPI / PCI: Fold acpi_pci_root_start() into acpi_pci_root_add()
ACPI: Change the ordering of acpi_bus_check_add()
ACPI: Replace struct acpi_bus_ops with enum type
ACPI: Reduce the usage of struct acpi_bus_ops
ACPI: Make acpi_bus_add() and acpi_bus_start() visibly different
ACPI: Change the ordering of PCI root bridge driver registrarion
ACPI: Separate adding ACPI device objects from probing ACPI drivers
Conflicts:
drivers/acpi/pci_root.c
With the recent creation of the drivers/irqchip/ directory, it is
desirable to move irq controller drivers here. At the moment, the only
driver here is irq-bcm2835, the driver for the irq controller found in
the ARM BCM2835 SoC, present in Rasberry Pi systems. This irq
controller driver was exporting its initialization function and its
irq handling function through a header file in
<linux/irqchip/bcm2835.h>.
When proposing to also move another irq controller driver in
drivers/irqchip, Rob Herring raised the very valid point that moving
things to drivers/irqchip was good in order to remove more stuff from
arch/arm, but if it means adding gazillions of headers files in
include/linux/irqchip/, it would not be very nice.
So, upon the suggestion of Rob Herring and Arnd Bergmann, this commit
introduces a small infrastructure that defines a central
irqchip_init() function in drivers/irqchip/irqchip.c, which is meant
to be called as the ->init_irq() callback of ARM platforms. This
function calls of_irq_init() with an array of match strings and init
functions generated from a special linker section.
Note that the irq controller driver initialization function is
responsible for setting the global handle_arch_irq() variable, so that
ARM platforms no longer have to define the ->handle_irq field in their
DT_MACHINE structure.
A global header, <linux/irqchip.h> is also added to expose the single
irqchip_init() function to the reset of the kernel.
A further commit moves the BCM2835 irq controller driver to this new
small infrastructure, therefore removing the include/linux/irqchip/
directory.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
[rob.herring: reword commit message to reflect use of linker sections.]
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
The External Proxy Facility in FSL BookE chips allows the interrupt
controller to automatically acknowledge an interrupt as soon as a
core gets its pending external interrupt delivered.
Today, user space implements the interrupt controller, so we need to
check on it during such a cycle.
This patch implements logic for user space to enable EPR exiting,
disable EPR exiting and EPR exiting itself, so that user space can
acknowledge an interrupt when an external interrupt has successfully
been delivered into the guest vcpu.
Signed-off-by: Alexander Graf <agraf@suse.de>
The USB 2.0 specification says that bMaxPower is the maximum power
consumption expressed in 2 mA units and the USB 3.0 specification says
that it is expressed in 8 mA units.
This patch renames bMaxPower to MaxPower and the various /2 and *2 are
removed. Before reporting the config descriptor, the proper value is
computer based on the speed, all in-tree users are updated. MaxPower is
also increased to u16 so we can store the nokia gadget value which is
larger than the max value allowed for u8.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
BCMA is a Broadcom specific bus with devices AKA cores. All recent BCMA
based SoCs have gigabit ethernet provided by the GBit MAC core. This
patch adds driver for such a cores registering itself as a netdev. It
has been tested on a BCM4706 and BCM4718 chipsets.
In the kernel tree there is already b44 driver which has some common
things with bgmac, however there are many differences that has led to
the decision or writing a new driver:
1) GBit MAC cores appear on BCMA bus (not SSB as in case of b44)
2) There is 64bit DMA engine which differs from 32bit one
3) There is no CAM (Content Addressable Memory) in GBit MAC
4) We have 4 TX queues on GBit MAC devices (instead of 1)
5) Many registers have different addresses/values
6) RX header flags are also different
The driver in it's state is functional how, however there is of course
place for improvements:
1) Supporting more net_device_ops
2) SUpporting more ethtool_ops
3) Unaligned addressing in DMA
4) Writing separated PHY driver
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 3a50597de8 ("KEYS: Make the session and process keyrings
per-thread") removed the definition of the thread_group_cred structure,
but left a now unused pointer in struct cred.
Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RCU free request_queue so that blkcg_gq->q can be dereferenced under
RCU lock. This will be used to implement hierarchical stats.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
We have skb_mac_header_was_set() helper to tell if mac_header
was set on a skb. We would like the same for transport_header.
__netif_receive_skb() doesn't reset the transport header if already
set by GRO layer.
Note that network stacks usually reset the transport header anyway,
after pulling the network header, so this change only allows
a followup patch to have more precise qdisc pkt_len computation
for GSO packets at ingress side.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
VMCI head config patch Adds all the necessary files to enable building of the VMCI
module with the Linux Makefiles and Kconfig systems. Also adds the header files used
for building modules against the driver.
Signed-off-by: George Zhang <georgezhang@vmware.com>
Acked-by: Andy king <acking@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, rcutorture traces every read-side access. This can be
problematic because even a two-minute rcutorture run on a two-CPU system
can generate 28,853,363 reads. Normally, only a failing read is of
interest, so this commit traces adjusts rcutorture's tracing to only
trace failing reads. The resulting event tracing records the time
and the ->completed value captured at the beginning of the RCU read-side
critical section, allowing correlation with other event-tracing messages.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
[ paulmck: Add fix to build problem located by Randy Dunlap based on
diagnosis by Steven Rostedt. ]
From Stephen Warren:
ARM/...: timer and clock events cleanup, and remove struct sys_timer
This branch contains a number of cleanups and unifications to various
timer- clock-events- and ARM timer code. The main points are:
1) Convert arch_gettimeoffset to a pointer, so that architectures with
multiple timer implementations can simply set this standard pointer
rather than maintaining their own arch-specific pointers for the
same purpose. Various architectures are converted to using this new
feature.
2) Conversion of ARM timer implementations to use clock_event_devices's
suspend/resume operations, rather than the ARM-specific sys_timer
versions. Thus, the ARM code begins to use more common infra-structure
rather than arch-specific code.
3) Removal of ARM's struct sys_timer completely, now that everything uses
common code.
4) Introduction of drivers/clocksource/clksrc-of.c, which allows ARM clock
source implementations to be moved into drivers/clocksource, with the
need to add SoC-specific header files for each timer initialization
function; instead, all enabled implementations are registered into a
table which a single core function iterates over, and calls the
relevant initialization functions based on device tree. At least the
Tegra and BCM2835 clocksource implementations will use this feature in
the 3.9 kernel cycle.
* tag 'swarren-for-3.9-arm-timer-rework' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra:
clocksource: add common of_clksrc_init() function
ARM: delete struct sys_timer
ARM: remove struct sys_timer suspend and resume fields
ARM: samsung: register syscore_ops for timer resume directly
ARM: ux500: convert timer suspend/resume to clock_event_device
ARM: sa1100: convert timer suspend/resume to clock_event_device
ARM: pxa: convert timer suspend/resume to clock_event_device
ARM: at91: convert timer suspend/resume to clock_event_device
ARM: set arch_gettimeoffset directly
m68k: set arch_gettimeoffset directly
time: convert arch_gettimeoffset to a pointer
cris: move usec/nsec conversion to do_slow_gettimeoffset
Signed-off-by: Olof Johansson <olof@lixom.net>
The spi-pxa2xx-pci glue driver had to implement pxa_ssp_request()/free() in
order to support the spi-pxa2xx platform driver. Since the ACPI enabled
platforms can use the same platform driver we would need to implement
pxa_ssp_request()/free() in some central place that can be shared by the
ACPI and PCI glue code.
Instead of doing that we can make pxa_ssp_request()/free() to be available
only when CONFIG_ARCH_PXA is set. On other arches these are being stubbed
out in preference to passing the ssp_device from the platform data
directly.
We also change the SPI bus number to be taken from ssp->port_id instead of
platform device id. This way the supporting code that passes the ssp can
decide the number (or it can set it to the same as pdev->id).
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
commit c045e3f13 (ARM: imx: include iram.h rather than mach/iram.h) changed the
location of iram.h, which causes the following build error when building the coda
driver:
drivers/media/platform/coda.c:27:23: error: mach/iram.h: No such file or directory
drivers/media/platform/coda.c: In function 'coda_probe':
drivers/media/platform/coda.c:2000: error: implicit declaration of function 'iram_alloc'
drivers/media/platform/coda.c:2001: warning: assignment makes pointer from integer without a cast
drivers/media/platform/coda.c: In function 'coda_remove':
drivers/media/platform/coda.c:2024: error: implicit declaration of function 'iram_free'
Since the content of iram.h is not imx specific, move it to
include/linux/platform_data/imx-iram.h instead. This is an intermediate solution
until the i.MX iram allocator is converted to the generic SRAM allocator.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
device_control is an optional and not implemented in all DMA drivers.
Any calls to these will result in a NULL pointer dereference. dmatest
makes two of these calls when completing the kernel thread and removing
the module. These are corrected by calling the dmaengine_device_control
wrapper and checking for a non-existant device_control function pointer
there.
Signed-off-by: Jon Mason <jon.mason@intel.com>
CC: Vinod Koul <vinod.koul@intel.com>
CC: Dan Williams <djbw@fb.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
commit b14dab792dee(DMAEngine: Define interleaved transfer request api) adds
interleaved request api, this patch adds the dmaengine_prep_interleaved_dma
just like we have dmaengine_prep_ for other modes to avoid drivers call:
xxx_chan->device->device_prep_interleaved_dma().
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
In the current implementation of the OF DMA helpers, read-copy-update (RCU)
linked lists are being used for storing and accessing the DMA controller data.
This part of implementation is based upon V2 of the DMA helpers by Nicolas [1].
During a recent review of RCU, it became apparent that the code is missing the
required rcu_read_lock()/unlock() calls as well as synchronisation calls before
freeing any memory protected by RCU.
Having looked into adding the appropriate RCU calls to protect the DMA data it
became apparent that with the current DMA helper implementation, using RCU is
not as attractive as it may have been before. The main reasons being that ...
1. We need to protect the DMA data around calls to the xlate function.
2. The of_dma_simple_xlate() function calls the DMA engine function
dma_request_channel() which employs a mutex and so could sleep.
3. The RCU read-side critical sections must not sleep and so we cannot hold
an RCU read lock around the xlate function.
Therefore, instead of using RCU, an alternative for this use-case is to employ
a simple spinlock inconjunction with a usage count variable to keep track of
how many current users of the DMA data structure there are. With this
implementation, the DMA data cannot be freed until all current users of the
DMA data are finished.
This patch is based upon the DMA helpers fix for potential deadlock [2].
[1] http://article.gmane.org/gmane.linux.ports.arm.omap/73622
[2] http://marc.info/?l=linux-arm-kernel&m=134859982520984&w=2
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
dw_dmac driver already supports device tree but it used to have its platform
data passed the non-DT way.
This patch does following changes:
- pass platform data via DT, non-DT way still takes precedence if both are used.
- create generic filter routine
- Earlier slave information was made available by slave specific filter routines
in chan->private field. Now, this information would be passed from within dmac
DT node. Slave drivers would now be required to pass bus_id (a string) as
parameter to this generic filter(), which would be compared against the slave
data passed from DT, by the generic filter routine.
- Update binding document
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Fixed __devinit usage]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Firmware may have assigned PCI BARs for hot-added devices, so reserve
those resources before trying to allocate more.
[bhelgaas: move empty weak definition here]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Jonathan says:
First round of IIO new stuff and cleanups for 3.9
Here we have:
* RTC driver for the hid-sensor hubs. This is routed through here with
agreement of Jiri Kosina and Andrew Morton.
* Some small patches doing dead code removal and fixing some comments.
* max1363 - move to the triggered_buffer helpers (basically duplicate code
removal).
* lp8788 - parent device change from the i2c device to the intermediate mfd.
So the bulk of what we have is actually outside the IIO tree but the RTC
driver in question is dependent on some patches that directly effect IIO so
I am routing it through IIO with the agreement of the relevant maintainers
(Andrew is acting as maintainer of RTC at the moment). The majority of
HID-sensor related code is in IIO and it now crosses 3 subsystems so it
was going to be a bit awkward whatever route it took.
Pull namei.h missing include fix from Al Viro.
The new use of ESTALE in namei.h can cause compile failures on ARM with
certain configurations due to lack of errno.h.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
namei.h: include errno.h
Implement cgroup_rightmost_descendant() which returns the right most
descendant of the specified cgroup. This can be used to skip the
cgroup's subtree while iterating with
cgroup_for_each_descendant_pre().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
5edee61ede ("cgroup: cgroup_subsys->fork() should be called after the
task is added to css_set") removed cgroup_fork_callbacks() but forgot
to remove its dummy version for !CONFIG_CGROUPS. Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
This extracts the platform data that we will keep generic
from the U300 platform and associates it with the COH901318
driver in <linux/platform_data/dma-coh901318.h>.
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This is based upon the work by Benoit Cousson [1] and Nicolas Ferre [2]
to add some basic helpers to retrieve a DMA controller device_node and the
DMA request/channel information.
Aim of DMA helpers
- The purpose of device-tree is to describe the capabilites of the hardware.
Thinking about DMA controllers purely from the context of the hardware to
begin with, we can describe a device in terms of a DMA controller as
follows ...
1. Number of DMA controllers
2. Number of channels (maybe physical or logical)
3. Mapping of DMA requests signals to DMA controller
4. Number of DMA interrupts
5. Mapping of DMA interrupts to channels
- With the above in mind the aim of the DT DMA helper functions is to extract
the above information from the DT and provide to the appropriate driver.
However, due to the vast number of DMA controllers and not all are using a
common driver (such as DMA Engine) it has been seen that this is not a
trivial task. In previous discussions on this topic the following concerns
have been raised ...
1. How does the binding support devices with multiple DMA controllers?
2. How to support both legacy DMA controllers not using DMA Engine as
well as those that support DMA Engine.
3. When using with DMA Engine how do we support the various
implementations where the opaque filter function parameter differs
between implementations?
4. How do we handle DMA channels that are identified with a string
versus a integer?
- Hence the design of the DMA helpers has to accomodate the above or align on
an agreement what can be or should be supported.
Design of DMA helpers
1. Registering DMA controllers
In the case of DMA controllers that are using DMA Engine, requesting a
channel is performed by calling the following function.
struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
dma_filter_fn filter_fn,
void *filter_param);
The mask variable is used to match a type of the device controller in a list
of controllers. The filter_fn and filter_param are used to identify the
required dma channel and return a handle to the dma channel of type dma_chan.
From the examples I have seen, the mask and filter_fn are constant
for a given DMA controller and therefore, we can specify these as controller
specific data when registering the DMA controller with the device-tree DMA
helpers.
The filter_param variable is of an unknown type and is typically specific
to the DMA engine implementation for a given DMA controller. To allow some
flexibility in the type and formating of this filter_param we employ an
xlate to translate the device-tree binding information into the appropriate
format. The xlate function used for a DMA controller can also be specified
when registering the DMA controller with the device-tree DMA helpers.
Based upon the above, a function for registering the DMA controller with the
DMA helpers now looks like the below. The data variable is used to pass a
pointer to DMA controller specific data used by the xlate function.
int of_dma_controller_register(struct device_node *np,
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *),
void *data)
For example, in the case where DMA engine is used, we define the following
structure (that stores the DMA engine capability mask and filter function)
and pass this to the data variable in the above function.
struct of_dma_filter_info {
dma_cap_mask_t dma_cap;
dma_filter_fn filter_fn;
};
2. Representing and requesting channel information
Please see the dma binding documentation included in this patch for a
description of how DMA controllers and client information should be
represented with device-tree. For more information on how this binding
came about please see [3]. In addition to this, feedback received from
the Linux kernel summit showed a consensus (among those who attended) to
use a name to identify DMA client information [4].
A DMA channel can be requested by calling the following function, where name
is a required parameter used for identifying a DMA channel. This function
has been designed to return a structure of type dma_chan to work with the
DMA engine driver. Note that if DMA engine is used then drivers should be
using the DMA engine API dma_request_slave_channel() (implemented in part 2
of this series, "dmaengine: add helper function to request a slave DMA
channel") which will in turn call the below function if device-tree is
present. The aim being to have a common DMA engine interface regardless of
whether device tree is being used.
struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
char *name)
3. Supporting legacy devices not using DMA Engine
These devices present a problem, as there may not be a uniform way to easily
support them with regard to device tree. Ideally, these should be migrated
to DMA engine. However, if this is not possible, then they should still be
able to use this binding, the only constaint imposed by this implementation
is that when requesting a DMA channel via of_dma_request_slave_channel(), it
will return a type of dma_chan.
This implementation has been tested on OMAP4430 using the kernel v3.6-rc5. I
have validated that MMC is working on the PANDA board with this implementation.
My development branch for testing on OMAP can be found here [5].
v6: - minor corrections in DMA binding documentation
v5: - minor update to binding documentation
- added loop to exhaustively search for a slave channel in the case where
there could be alternative channels available
v4: - revert the removal of xlate function from v3
- update the proposed binding format and APIs based upon discussions [3]
v3: - avoid passing an xlate function and instead pass DMA engine parameters
- define number of dma channels and requests in dma-controller node
v2: - remove of_dma_to_resource API
- make property #dma-cells required (no fallback anymore)
- another check in of_dma_xlate_onenumbercell() function
[1] http://article.gmane.org/gmane.linux.drivers.devicetree/12022
[2] http://article.gmane.org/gmane.linux.ports.arm.omap/73622
[3] http://marc.info/?l=linux-omap&m=133582085008539&w=2
[4] http://pad.linaro.org/arm-mini-summit-2012
[5] https://github.com/jonhunter/linux/tree/dev-dt-dma
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <djbw@fb.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Reviewed-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Currently slave DMA channels are requested by calling dma_request_channel()
and requires DMA clients to pass various filter parameters to obtain the
appropriate channel.
With device-tree being used by architectures such as arm and the addition of
device-tree helper functions to extract the relevant DMA client information
from device-tree, add a new function to request a slave DMA channel using
device-tree. This function is currently a simple wrapper that calls the
device-tree of_dma_request_slave_channel() function.
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <djbw@fb.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Reviewed-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
The structure with common attributes for hid-sensors isn't specific
to the iio-subsystem, so rename it to hid_sensor_common.
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The stuff in hid-sensor-attributes.h is needed by every piece which
uses hid-sensor-hub and merging it into hid-sensor-hub.h makes it accessible
from outside the iio subdirectory.
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
These are Usage IDs for the attributes year, month, day,
hour, minute and second, needed to read HID time sensors.
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
As most of the charger chips come with two kinds of safety features
related to timing:
1. Watchdog Timer (interms of seconds/mins)
2. Safety Timer (interms of hours)
This patch adds these to fault causes in POWER_SUPPLY_PROP_HEALTH_* enums
so that whenever there is either watchdog timeout or safety timer timeout
driver could notify the user space accurately about the fault and will
also be helpful for debug.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
