Add DMA engine support to the OMAP2 NAND driver. This supplements the
private DMA API implementation contained within this driver, and the
driver can be independently switched at build time between using DMA
engine and the private DMA API.
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Two modes are supported: 4-bit and 8-bit error correction.
Note that 4-bit mode is only confirmed to work on OMAP3630 ES 1.x,
x >= 1. The OMAP3 GPMC hardware BCH engine computes remainder
polynomials, it does not provide automatic error location and
correction: this step is implemented using the BCH library.
This implementation only protects page data, there is no support
for protecting user-defined spare area bytes (this could be added
with few modifications); therefore, it cannot be used with YAFFS2
or other similar filesystems that depend on oob storage.
Before being stored to nand flash, hardware BCH ecc is adjusted
so that an erased page has a valid ecc; thus allowing correction of
bitflips in blank pages (also common on 4-bit devices).
BCH correction mode is selected at runtime by setting platform data
parameter 'ecc_opt' to value OMAP_ECC_BCH4_CODE_HW or
OMAP_ECC_BCH8_CODE_HW.
This code has been tested with mtd test modules, UBI and UBIFS on a
BeagleBoard revC3 (OMAP3530 ES3.0 + Micron NAND 256MiB 1,8V 16-bit).
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If a context switch occurs in function omap_wait() just before the
while loop is entered, then upon return from context switch the
timeout may already have elapsed: in that case, status is never
read from NAND device, and omap_wait() returns an error.
This failure has been experimentally observed during stress tests.
This patch ensures a NAND status read is always performed before
returning, as in the generic nand_wait() function.
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If prefetch engine is busy, current code "forgets" to call
dma_unmap_single(), which results in a deadlock later, so add it.
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Flash device drivers initialize 'ecc_strength' in struct mtd_info, which is the
maximum number of bit errors that can be corrected in one writesize region.
Drivers using the nand interface intitialize 'strength' in struct nand_ecc_ctrl,
which is the maximum number of bit errors that can be corrected in one ecc step.
Nand infrastructure code translates this to 'ecc_strength'.
Also for nand drivers, the nand infrastructure code sets ecc.strength for ecc
modes NAND_ECC_SOFT, NAND_ECC_SOFT_BCH, and NAND_ECC_NONE. It is set in the
driver for all other modes.
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The first 3 arguments of 'mtd_device_parse_register()' are pointers,
but many callers pass '0' instead of 'NULL'. Fix this globally. Thanks
to coccinelle for making it easy to do with the following semantic patch:
@@
expression mtd, types, parser_data, parts, nr_parts;
@@
(
-mtd_device_parse_register(mtd, 0, parser_data, parts, nr_parts)
+mtd_device_parse_register(mtd, NULL, parser_data, parts, nr_parts)
|
-mtd_device_parse_register(mtd, types, 0, parts, nr_parts)
+mtd_device_parse_register(mtd, types, NULL, parts, nr_parts)
|
-mtd_device_parse_register(mtd, types, parser_data, 0, nr_parts)
+mtd_device_parse_register(mtd, types, parser_data, NULL, nr_parts)
)
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch converts the drivers in drivers/mtd/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* git://git.infradead.org/mtd-2.6: (226 commits)
mtd: tests: annotate as DANGEROUS in Kconfig
mtd: tests: don't use mtd0 as a default
mtd: clean up usage of MTD_DOCPROBE_ADDRESS
jffs2: add compr=lzo and compr=zlib options
jffs2: implement mount option parsing and compression overriding
mtd: nand: initialize ops.mode
mtd: provide an alias for the redboot module name
mtd: m25p80: don't probe device which has status of 'disabled'
mtd: nand_h1900 never worked
mtd: Add DiskOnChip G3 support
mtd: m25p80: add EON flash EN25Q32B into spi flash id table
mtd: mark block device queue as non-rotational
mtd: r852: make r852_pm_ops static
mtd: m25p80: add support for at25df321a spi data flash
mtd: mxc_nand: preset_v1_v2: unlock all NAND flash blocks
mtd: nand: switch `check_pattern()' to standard `memcmp()'
mtd: nand: invalidate cache on unaligned reads
mtd: nand: do not scan bad blocks with NAND_BBT_NO_OOB set
mtd: nand: wait to set BBT version
mtd: nand: scrub BBT on ECC errors
...
Fix up trivial conflicts:
- arch/arm/mach-at91/board-usb-a9260.c
Merged into board-usb-a926x.c
- drivers/mtd/maps/lantiq-flash.c
add_mtd_partitions -> mtd_device_register vs changed to use
mtd_device_parse_register.
We are cleaning up the implicit presence of module.h that these
drivers are taking advantage of. Fix them in advance of the
cleanup operation.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Start moving away from the MTD_DEBUG_LEVEL messages. The dynamic
debugging feature is a generic kernel feature that provides more
flexibility.
(See Documentation/dynamic-debug-howto.txt)
Also fix some punctuation, indentation, and capitalization that went
along with the affected lines.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Replace custom invocations of parse_mtd_partitions and mtd_device_register
with common mtd_device_parse_register call. This would bring: standard
handling of all errors, fallback to default partitions, etc.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Since 'cmdline, NULL' is now a default for parse_mtd_partitions, don't specify
this in every driver, instead pass NULL to force parse_mtd_partitions
to use default.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Convert to mtd_device_register() and remove the CONFIG_MTD_PARTITIONS
preprocessor conditionals as partitioning is always available.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When reading/writing a subpage (When HW ECC is not available/enabled)
for number of bytes not aligned to 4, the mis-aligned bytes are handled
first (by cpu copy method) before enabling the Prefetch engine to/from
'p'(start of buffer 'buf'). Then it reads/writes rest of the bytes with
the help of Prefetch engine, if available, or again using cpu copy method.
Currently, reading/writing of rest of bytes, is not done correctly since
its trying to read/write again to/from begining of buffer 'buf',
overwriting the mis-aligned bytes.
Read & write using prefetch engine got broken in commit '2c01946c'.
We never hit a scenario of not getting 'gpmc_prefetch_enable' call
success. So, problem did not get caught up.
Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com>
Signed-off-by: Vimal Singh <vimal.newwork@gmail.com>
Reported-by: Bryan DE FARIA <bdefaria@adeneo-embedded.com>
Cc: stable@kernel.org [2.6.35+]
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
nand_scan calls nand_scan_tail and here we got a ecc.layout and calculate
oobavail for this layout. After calling nand_scan, we change the layout pointer
if OMAP_ECC_HAMMING_CODE_HW_ROMCODE is set. This results in not calcluated
oobavail. Mountig as jffs2 is not possible.
To fix that nand_scan has to split up in nand_scan_ident and nand_scan_tail
setting ecc.layout between these calls. So nand_scan_tail calculates oobvail
for the used layout. This is also done in serveral other platforms.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Reviewed-by: Vimal Singh <vimal.newwork@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
[media] rc: update for bitop name changes
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
lib, arch: add filter argument to show_mem and fix private implementations
SLUB: Write to per cpu data when allocating it
slub: Fix debugobjects with lockless fastpath
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
...
NOTE!
This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.
To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.
In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (258 commits)
omap: zoom: host should not pull up wl1271's irq line
arm: plat-omap: iommu: fix request_mem_region() error path
OMAP2+: Common CPU DIE ID reading code reads wrong registers for OMAP4430
omap4: mux: Remove duplicate mux modes
omap: iovmm: don't check 'da' to set IOVMF_DA_FIXED flag
omap: iovmm: disallow mapping NULL address when IOVMF_DA_ANON is set
omap2+: mux: Fix compile when CONFIG_OMAP_MUX is not selected
omap4: board-omap4panda: Initialise the serial pads
omap3: board-3430sdp: Initialise the serial pads
omap4: board-4430sdp: Initialise the serial pads
omap2+: mux: Add macro for configuring static with omap_hwmod_mux_init
omap2+: mux: Remove the use of IDLE flag
omap2+: Add separate list for dynamic pads to mux
perf: add OMAP support for the new power events
OMAP4: Add IVA OPP enteries.
OMAP4: Update Voltage Rail Values for MPU, IVA and CORE
OMAP4: Enable 800 MHz and 1 GHz MPU-OPP
OMAP3+: OPP: Replace voltage values with Macros
OMAP3: wdtimer: Fix CORE idle transition
Watchdog: omap_wdt: add fine grain runtime-pm
...
Fix up various conflicts in
- arch/arm/mach-omap2/board-omap3evm.c
- arch/arm/mach-omap2/clock3xxx_data.c
- arch/arm/mach-omap2/usb-musb.c
- arch/arm/plat-omap/include/plat/usb.h
- drivers/usb/musb/musb_core.h
The number of corrected ECC errors should be reported since other MTD
systems make use of this information (such as UBI data scrubbing).
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Since 43cc71eed1 (platform: prefix MODALIAS
with "platform:"), the platform modalias is prefixed with "platform:".
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
This patch overrides nand ecc layout and bad block descriptor (for 8-bit
device) to support hw ecc in romcode layout. So as to have in sync with ecc
layout throughout; i.e. x-loader, u-boot and kernel.
This enables to flash x-loader, u-boot, kernel, FS images from kernel itself
and compatiable with other tools.
This patch does not enables this feature by default and need to pass from
board file to enable for any board.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch makes it possible to select sw or hw (different layout options)
ecc scheme supported by omap nand driver.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Configure the FIFO THREASHOLD value different for read and write to keep busy
both filling and to drain out of FIFO at reading and writing.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
nand transfer type (sDMA, Polled, prefetch) can be select from board file,
enabling all transfer type in driver, by default.
this helps in multi-omap build and to select different transfer type for
different board.
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
zoom3 and 3630-sdp having the x16 nand device.
This patch configure gpmc as x16 and select the currect function in driver
for polled mode (without prefetch enable) transfer.
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Commit 2c01946c6b (omap3 nand: cleanup
virtual address usages) wrongly enabled CONFIG_MTD_NAND_OMAP_HWECC
which breaks boards like beagle and pandora that use software ECC
for write.
Boards like beagle and pandora uses sw ecc for write (e.g. binary flushed
from u-boot) and read from kernel.
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
[tony@atomide.com: updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Conflicts:
drivers/mtd/mtd_blkdevs.c
Merge Grant's device-tree bits so that we can apply the subsequent fixes.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch fixes sparse warning for static declaration of variable "use_dma"
drivers/mtd/nand/omap2.c:114:11: warning: symbol 'use_dma' was not declared. Should it be static?
Signed-off-by: G, Manjunath Kondaiah <manjugk@ti.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch removes direct reference of gpmc address from generic nand platform code.
Nand platform code now uses wrapper functions which are implemented in gpmc module.
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
few functions added in gpmc module and to be used by other drivers like NAND.
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.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>
There is a bug in nand prefetch read routine, which comes into effect
only if nand device is a 16-bit device (as we have in zoom boards).
This bug is effective only with below combination of conditions:
1. nand deivce, in use, is a 16 bit device
2. nand driver supports 'subpage' read
3. SW ECC is in use
This was not seen old kernel (ex: .23), because when, in early days,
we tested this (nand prefetch read in LDP boards) there was no
'subpage read' support.
Later when we had subpage read in (.27) kernel, we had hw ecc enabled
always in our internal tree. So, we missed this bug.
This patch fixes the issue.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Removing OMAP NAND driver, when loaded as a module, gives error and
does not get success. This fixes this and makes driver loadable and
removable run time.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Fixing below warning in compilation:
drivers/mtd/nand/omap2.c: In function 'omap_write_buf_dma_pref':
drivers/mtd/nand/omap2.c:508: warning: passing argument 2 of
'omap_nand_dma_transfer' discards qualifiers from pointer target type
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Introducing 'gpmc-nand.c' for GPMC specific NAND init.
For example: GPMC timing parameters and all.
This patch also migrates gpmc related calls from 'nand/omap2.c'
to 'gpmc-nand.c'.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Move the remaining headers under plat-omap/include/mach
to plat-omap/include/plat. Also search and replace the
files using these headers to include using the right path.
This was done with:
#!/bin/bash
mach_dir_old="arch/arm/plat-omap/include/mach"
plat_dir_new="arch/arm/plat-omap/include/plat"
headers=$(cd $mach_dir_old && ls *.h)
omap_dirs="arch/arm/*omap*/ \
drivers/video/omap \
sound/soc/omap"
other_files="drivers/leds/leds-ams-delta.c \
drivers/mfd/menelaus.c \
drivers/mfd/twl4030-core.c \
drivers/mtd/nand/ams-delta.c"
for header in $headers; do
old="#include <mach\/$header"
new="#include <plat\/$header"
for dir in $omap_dirs; do
find $dir -type f -name \*.[chS] | \
xargs sed -i "s/$old/$new/"
done
find drivers/ -type f -name \*omap*.[chS] | \
xargs sed -i "s/$old/$new/"
for file in $other_files; do
sed -i "s/$old/$new/" $file
done
done
for header in $(ls $mach_dir_old/*.h); do
git mv $header $plat_dir_new/
done
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch adds DMA mode support for nand prefetch/post-write engine.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch adds prefetch support to access nand flash in mpu mode.
This patch also adds 8-bit nand support (omap_read/write_buf8).
Prefetch can be used for both 8- and 16-bit devices.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We need to include jiffies.h manually in some cases, and the status
returned from omap_wait() was broken in two separate ways.
Also add cond_resched() to the loop.
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This driver is present in the OMAP tree, now pushing it to MTD.
Original author(s):
Jian Zhang <jzhang@ti.com>
Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Cc: Jian Zhang <jzhang@ti.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>