- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
USHORT_MAX/SHORT_MAX/SHORT_MIN.
- Make SHRT_MIN of type s16, not int, for consistency.
[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (25 commits)
sh: fix up sh7785lcr_32bit_defconfig.
arch/sh/lib/strlen.S: Checkpatch cleanup
sh: fix up sh7786 dmaengine build.
sh: guard cookie consistency across termination in the DMA driver
sh: prevent the DMA driver from unloading, while in use
sh: fix Oops in the serial SCI driver
sh: allow platforms to specify SD-card supported voltages
mmc: let MFD's provide supported Vdd card voltages to tmio_mmc
sh: disable SD-card write-protection detection on kfr2r09
mfd: pass platform flags down to the tmio_mmc driver
tmio: add a platform flag to disable card write-protection detection
sh: Add SDHI DMA support to migor
sh: Add SDHI DMA support to kfr2r09
sh: Add SDHI DMA support to ms7724se
sh: Add SDHI DMA support to ecovec
mmc: add DMA support to tmio_mmc driver, when used on SuperH
sh: prepare the SDHI MFD driver to pass DMA configuration to tmio_mmc.c
mmc: prepare tmio_mmc for passing of DMA configuration from the MFD cell
sh: add DMA slave definitions to sh7724
sh: add DMA slaves for two SDHI controllers to sh7722
...
Add DMA Engine API driver for the PL330 DMAC.
This driver is supposed to be reusable by various
platforms that have one or more PL330 DMACs.
Atm, DMA_SLAVE and DMA_MEMCPY capabilities have been
implemented.
Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Reviewed-by: Linus Walleij <linus.walleij@stericsson.com>
[dan.j.williams@intel.com: missing slab.h and ->device_control() fixups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
If all descriptors on a channel are terminated or the channel is released,
update the completed cookie counter to match the last cookie. This prevents
inconsistency warning on resumed DMA operation.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This prevents the driver from unloading, while it is in use. Unloading of the
driver, while its DMA channels are held, leads to a kernel Oops.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Merging in current state of Linus' tree to deal with merge conflicts and
build failures in vio.c after merge.
Conflicts:
drivers/i2c/busses/i2c-cpm.c
drivers/i2c/busses/i2c-mpc.c
drivers/net/gianfar.c
Also fixed up one line in arch/powerpc/kernel/vio.c to use the
correct node pointer.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
.name, .match_table and .owner are duplicated in both of_platform_driver
and device_driver. This patch is a removes the extra copies from struct
of_platform_driver and converts all users to the device_driver members.
This patch is a pretty mechanical change. The usage model doesn't change
and if any drivers have been missed, or if anything has been fixed up
incorrectly, then it will fail with a compile time error, and the fixup
will be trivial. This patch looks big and scary because it touches so
many files, but it should be pretty safe.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
DMAENGINE: extend the control command to include an arg
async_tx: trim dma_async_tx_descriptor in 'no channel switch' case
DMAENGINE: DMA40 fix for allocation of logical channel 0
DMAENGINE: DMA40 support paused channel status
dmaengine: mpc512x: Use resource_size
DMA ENGINE: Do not reset 'private' of channel
ioat: Remove duplicated devm_kzalloc() calls for ioatdma_device
ioat3: disable cacheline-unaligned transfers for raid operations
ioat2,3: convert to producer/consumer locking
ioat: convert to circ_buf
DMAENGINE: Support for ST-Ericssons DMA40 block v3
async_tx: use of kzalloc/kfree requires the include of slab.h
dmaengine: provide helper for setting txstate
DMAENGINE: generic channel status v2
DMAENGINE: generic slave control v2
dma: timb-dma: Update comment and fix compiler warning
dma: Add timb-dma
DMAENGINE: COH 901 318 fix bytesleft
DMAENGINE: COH 901 318 rename confusing vars
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (127 commits)
sh: update defconfigs.
sh: Fix up the NUMA build for recent LMB changes.
sh64: provide a stub per_cpu_trap_init() definition.
sh: fix up CONFIG_KEXEC=n build.
sh: fixup the docbook paths for clock framework shuffling.
driver core: Early dev_name() depends on slab_is_available().
sh: simplify WARN usage in SH clock driver
sh: Check return value of clk_get on ms7724
sh: Check return value of clk_get on ecovec24
sh: move sh clock-cpg.c contents to drivers/sh/clk-cpg.c
sh: move sh clock.c contents to drivers/sh/clk.
sh: move sh asm/clock.h contents to linux/sh_clk.h V2
sh: remove unused clock lookup
sh: switch boards to clkdev
sh: switch sh4-202 to clkdev
sh: switch shx3 to clkdev
sh: switch sh7757 to clkdev
sh: switch sh7763 to clkdev
sh: switch sh7780 to clkdev
sh: switch sh7786 to clkdev
...
The following structure elements duplicate the information in
'struct device.of_node' and so are being eliminated. This patch
makes all readers of these elements use device.of_node instead.
(struct of_device *)->node
(struct dev_archdata *)->prom_node (sparc)
(struct dev_archdata *)->of_node (powerpc & microblaze)
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This adds an argument to the DMAengine control function, so that
we can later provide control commands that need some external data
passed in through an argument akin to the ioctl() operation
prototype.
[dan.j.williams@intel.com: fix up some missed conversions]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Saves 24 bytes per descriptor (64-bit) when the channel-switching
capabilities of async_tx are not required.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Fix for allocation failure of logical channel when event line
happens to be number 0.
Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Support determining whether a channel is paused or
not using the status function.
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Use the resource_size function instead of manually calculating the
resource size. This reduces the chance of introducing off-by-one
errors.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The member 'private' of 'struct dma_chan' is meant for passing
data between client and the controller driver.
The DMA client driver may point it to platform specific stuff after
acquiring the channel. So, it is the responsiblity of the same code
to reset it, if it must.
The DMA engine doesn't set it and hence, shouldn't reset it either.
This reseting of private by DMA Engine comes in the way of implementing
default channel settings during DMAC probe. That capability is useful
for not having the clients to always provide platform specific data,
like Rx/Tx FIFO addresses, which usually doesn't change across channel
requests.
Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* 'sh/for-2.6.34' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
sh: fix a number of Oopses and leaks in SH framebuffer driver
SH: fix error paths in DMA driver
sh: sh7751 pci controller io port fix
sh: Fix maximum number of SCIF ports in R2D defconfigs
SH: fix TS field shift calculation for DMA drivers
The memory for ioatdma_device structure is being allocated in
alloc_ioatdma()
Signed-off-by: Minskey Guo <chaohong_guo@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
There are cases where cacheline-unaligned raid operations can hang the
dma channel. Simply disable these operations by increasing the
alignment constraints published to async_tx. The raid456 driver always
issues page aligned requests, so the only in-kernel user of the ioatdma
driver that is affected by this change is dmatest.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Use separate locks for the descriptor prep (producer) and descriptor
cleanup (consumer) paths. Allows the producer path to run concurrently
with the cleanup path. Inspired by Documentation/circular-buffer.txt.
Cc: David Howells <dhowells@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This enables autoloading of the TXx9 sound driver on RBTX4927.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
To: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Linux MIPS Mailing List <linux-mips@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1101/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If channel allocation is failing, mark the channel unused and give PM a chance
to power down the hardware.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Lists of DMA channels and slaves are not changed, make them constant. Besides,
SH7724 channel and slave configuration of both DMA controllers is identical,
remove the extra copy of the configuration data.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This is a straightforward driver for the ST-Ericsson DMA40 DMA
controller found in U8500, implemented akin to the existing
COH 901 318 driver.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Srinidh Kasagar <srinidhi.kasagar@stericsson.com>
Cc: STEricsson_nomadik_linux@list.st.com
Cc: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Convert the device_is_tx_complete() operation on the
DMA engine to a generic device_tx_status()operation which
can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE,
DMA_TX_PAUSED.
[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Convert the device_terminate_all() operation on the
DMA engine to a generic device_control() operation
which can now optionally support also pausing and
resuming DMA on a certain channel. Implemented for the
COH 901 318 DMAC as an example.
[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
An incremental patch which clarifies what the spinlock is used for
and fixes a compiler warning.
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Adds the support for the DMA engine withing the timberdale FPGA.
The DMA channels are strict device to host, or host to device
and can not be used for generic memcpy.
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This makes the function to get the number of bytes left in the
ongoing DMA transaction actually work: the old code did not take
neither lli:s nor queued jobs into account. Also fix a missing
spinlock while we're at it.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This fixes up the code with a lot of comments that make it readable,
rename things with opaque names like "data" into something more
appropriate, and remove some very confusing BUG() statements.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create a common platform data header file for the
shdma dmaengine driver. This is done by moving
common structures from sh asm/dmaengine.h to
linux/sh_dma.h. DMA registers are also copied from
sh asm/dma-register.h to make the code architecture
independent.
The sh header file asm/dmaengine.h is still kept
with the slave id enum. This allows us to keep the
old processor specific code as is and slowly move
over to slave id enums in per-processor headers.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Move SHDMA_SLAVE_NUMBER from asm/dmaengine.h to
shdma.h. Set it to 256 to support a wide range
of processors. The amount of memory consumed by
this change is limited to 256 bits.
While at it, rename to SH_DMA_SLAVE_NUMBER to
match with the rest of the file.
Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch replaces the sh_dmae_slave_chan_id enum
with an unsigned int. The purpose of this chainge is
to make it possible to separate the slave id enums
from the dmaengine header.
The slave id enums varies with processor model, so in
the future it makes sense to put these in the processor
specific headers together with the pinmux enums.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (56 commits)
doc: fix typo in comment explaining rb_tree usage
Remove fs/ntfs/ChangeLog
doc: fix console doc typo
doc: cpuset: Update the cpuset flag file
Fix of spelling in arch/sparc/kernel/leon_kernel.c no longer needed
Remove drivers/parport/ChangeLog
Remove drivers/char/ChangeLog
doc: typo - Table 1-2 should refer to "status", not "statm"
tree-wide: fix typos "ass?o[sc]iac?te" -> "associate" in comments
No need to patch AMD-provided drivers/gpu/drm/radeon/atombios.h
devres/irq: Fix devm_irq_match comment
Remove reference to kthread_create_on_cpu
tree-wide: Assorted spelling fixes
tree-wide: fix 'lenght' typo in comments and code
drm/kms: fix spelling in error message
doc: capitalization and other minor fixes in pnp doc
devres: typo fix s/dev/devm/
Remove redundant trailing semicolons from macros
fix typo "definetly" -> "definitely" in comment
tree-wide: s/widht/width/g typo in comments
...
Fix trivial conflict in Documentation/laptops/00-INDEX
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (26 commits)
sh: Convert sh to use read/update_persistent_clock
sh: Move PMB debugfs entry initialization to later stage
sh: Fix up flush_cache_vmap() on SMP.
sh: fix up MMU reset with variable PMB mapping sizes.
sh: establish PMB mappings for NUMA nodes.
sh: check for existing mappings for bolted PMB entries.
sh: fixed virt/phys mapping helpers for PMB.
sh: make pmb iomapping configurable.
sh: reworked dynamic PMB mapping.
sh: Fix up cpumask_of_pcibus() for the NUMA build.
serial: sh-sci: Tidy up build warnings.
sh: Fix up ctrl_read/write stragglers in migor setup.
serial: sh-sci: Add DMA support.
dmaengine: shdma: extend .device_terminate_all() to record partial transfer
sh: merge sh7722 and sh7724 DMA register definitions
sh: activate runtime PM for dmaengine on sh7722 and sh7724
dmaengine: shdma: add runtime PM support.
dmaengine: shdma: separate DMA headers.
dmaengine: shdma: convert to platform device resources
dmaengine: shdma: fix DMA error handling.
...
Rename for_each_bit to for_each_set_bit in the kernel source tree. To
permit for_each_clear_bit(), should that ever be added.
The patch includes a macro to map the old for_each_bit() onto the new
for_each_set_bit(). This is a (very) temporary thing to ease the migration.
[akpm@linux-foundation.org: add temporary for_each_bit()]
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the calling convention of ->timer_fn() and ->cleanup_fn() are unified
across hardware versions we can drop parameters to ioat_init_channel() and
unify ioat_is_dma_complete() implementations.
Both ->timer_fn() and ->cleanup_fn() are modified to expect a struct
dma_chan pointer.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The hardware automatically disables further interrupts after each event
until rearmed. This allows a delay to be injected between the occurence
of the interrupt and the running of the cleanup routine. The delay is
scaled by the descriptor backlog and then written to the INTRDELAY
register which specifies the number of microseconds to hold off
interrupt delivery after an interrupt event occurs. According to
powertop this reduces the interrupt rate from ~5000 intr/s to ~150
intr/s per without affecting throughput (simple dd to a raid6 array).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Since ioat_cleanup_preamble() and the update of the last completed
descriptor are not synchronized there is a chance that two cleanup threads
can see descriptors to clean. If the first cleans up all pending
descriptors then the second will trigger the BUG_ON.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Linus Torvalds