Currently there is a race in the MMC core between a card-detect
rescan work and the clock-gating work, scheduled from a command
completion. Fix it by removing the dedicated clock-gating mutex
and using the MMC standard locking mechanism instead.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <damm@opensource.se>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Fixes a cosmetic bug that affects printk() for SD-combo cards.
Reported-by: Prashanth Bhat <prashanth.bhat@manipal.net>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch is based on the commit "af51715079e7fb6b290e1881d63d815dc4de5011":
* Bugfix to that mmc_send_cxd_data() code: dma-to-stack is
unsafe/nonportable, so kmalloc a bounce buffer instead.
The driver may invalidate the mmc_card->csd when host driver uses dma.
So this subroutine also needs a kmalloc buffer.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
At power off, reset OCR mask to be the highest possible voltage
supported for the current mmc host.
This solves the re-initialization during the power up sequence.
The voltage may have been decreased due to the card accepts a lower
voltage than the voltage used during the initialization sequence.
We need to reset the voltage to by the host highest possible value
since according to specification the initialization must always be
done at high voltage.
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
When using mmc_try_claim_host the corresponding release
function is mmc_do_release_host, which then also must
be exported.
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Reviewed-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
During redetection of a SDIO card, a request for a new card RCA
was submitted to the card, but was then overwritten by the old RCA.
This caused the card to be deselected instead of selected when using
the incorrect RCA. This bug's been present since the "oldcard"
handling was introduced in 2.6.32.
Signed-off-by: Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com>
Reviewed-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Pawel Wieczorkiewicz <pawel.wieczorkiewicz@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some TOSHIBA MMC cards only support sector addressing even though the
size is < 2GB. According to JEDEC Spec JESD84-A441-1 the ocr register
(bits 30, 29) determine byte/sector mode. Use them.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
sdio_reset sends a CMD52 to reset the sdio card. This is highly
recommended for sdio cards being reinitialized. Since we do not
know if the card is being reinitialized we just send the command.
SD/eMMC cards are supposed to ignore the CMD before the CMD0.
Document why we are doing this.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
So we know the implementation and prototypes agree with each other.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This sdio card supports having its sdio clock shutdown.
It is also not using the SDIO IRQ, but rather uses a side gpio irq.
Signed-off-by: Pierre Tardy <tardyp@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some sdio card are not following sdio standard, and do not work
when the sdio bus's clock is gated.
To keep functionnality for all legacy driver, we turn this quirk on
for every sdio card.
Drivers needs to disable the quirk manually when someone verifies that
their supported card works with clock gating.
Signed-off-by: Pierre Tardy <tardyp@gmail.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some cards have quirks valid for every platforms using current
platform quirk hooks leads to a lot of code and debug duplication.
So we inspire a bit from what exists in PCI subsystem and do our own
per vendorid/deviceid quirk. We still drop the complexity of the pci
quirk system (with special section tables, and so on).
That can be added later if needed.
Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Since mmc clock gating can also be used as a power gating
tip, it's better to put the led blinking after having
ungated the clock.
Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Enhanced area feature is a new feature defined in eMMC4.4 standard. This
user data area provides higher performance/reliability, at the expense
of using twice the effective media space due to the area using SLC.
The MMC driver now reads out the enhanced area offset and size and adds
them to the device attributes in sysfs. Enabling the enhanced area can
only be done once, and should be done in manufacturing. To use this
feature, bit ERASE_GRP_DEF should also be set.
Documentation/ABI/testing/sysfs-devices-mmc describes the two new
attributes.
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
30201e7f3 ("mmc: skip detection of nonremovable cards on rescan")
allowed skipping detection of nonremovable cards on mmc_rescan().
The intention was to only skip detection of hardwired cards that
cannot be removed, so make sure this is indeed the case by directly
checking for (lack of) MMC_CAP_NONREMOVABLE, instead of using
mmc_card_is_removable(), which is overloaded with
CONFIG_MMC_UNSAFE_RESUME semantics.
The user-visible symptom of the bug this patch fixes is that no
"mmc: card XXXX removed" message appears in dmesg when a card is
removed and CONFIG_MMC_UNSAFE_RESUME=y.
Reported-and-tested-by: Dmitry Shmidt <dimitrysh@google.com>
Reported-and-tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This fixes a bug introduced by 807e8e4067 ("mmc: Fix sd/sdio/mmc
initialization frequency retries") that prevented SDIO drivers from
performing SDIO commands in their probe routines -- the above patch
called mmc_claim_host() before sdio_add_func(), which causes a deadlock
if an external SDIO driver calls sdio_claim_host().
Fix tested on an OLPC XO-1.75 with libertas on SDIO.
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Reviewed-and-Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
The card is not always clocked and the clock frequency zero is perfectly
legal, thus this code in mmc_set_data_timeout() may cause a division by
zero. It will be triggered more often if you're using software clock
gating but can be triggered under other conditions too.
Reported-by: Pierre Tardy <tardyp@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This way, the probe function may register debugfs files if it wants to.
This fixes a bug with mmc_test where mmc_test_register_file_test() is
called before the card's debugfs dir exists, and so it fails.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Rewrite and clean up mmc_rescan() to properly retry frequencies lower
than 400kHz. Failures can happen both in sd_send_* calls and
mmc_attach_*. Break out "mmc_rescan_try_freq" from the frequency
selection loop. Symmetrize claim/release logic in mmc_attach_* API,
and move the sd_send_* calls there to make mmc_rescan easier to read.
Signed-off-by: Andy Ross <andy.ross@windriver.com>
Reviewed-and-Tested-by: Hein Tibosch <hein_tibosch@yahoo.es>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
With the bus-width test patch, mmc_set_bus_width*() isn't called properly
when the driver doesn't set MMC_CAP_BUS_WIDTH and no DDR mode.
This patch fixes the regression by moving the call up before the cap test.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Since we make sure the clock is enabled in the mmc_host_clk_exit()
function we should expect a reference counter of 1, not 0.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some old MMC devices fail with the 4/8 bits the driver tries to use
exclusively. This patch adds a test for the given bus setup and falls
back to the lower bit mode (until 1-bit mode) when the test fails.
[Major rework and refactoring by tiwai]
[Quirk addition and many fixes by prakity]
Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
In case of failure, mmc_attach_sdio() will power off the SD bus.
Power it up and reinitialize before trying SD memory detection.
Reported-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Upon system resume, SDIO core must reinitialize cards that were
powered off during suspend.
If the card had its power kept during suspend (and thus it is
'powered-resumed'), SDIO core performs only a limited reinitializing,
mainly needed to make sure that the card wasn't removed/replaced.
If a __nonremovable__ card is powered-resumed, we can safely skip the
reinitializing phase.
Note: 9b966aa (mmc: sdio: fully reconfigure oldcard on resume) removed
the bus width reconfiguration since mmc_sdio_init_card already does it.
It is brought back now in case mmc_sdio_init_card is skipped.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Initial SDIO runtime PM implementation took a conservative approach
of powering up cards (and fully reinitializing them) on system suspend,
just before the suspend handlers of the relevant drivers were executed.
To avoid redundant power and reinitialization cycles, this patch removes
this behavior: if a card is already powered off when system suspend kicks
in, it is left at that state.
If a card is active when a system sleep starts, everything is
straightforward and works exactly like before. But if the card was
already suspended before the sleep began, then when the MMC core powers
it back up on resume, its run-time PM status has to be updated to reflect
the actual post-system sleep status.
The technique to do that is borrowed from the I2C runtime PM
implementation (for more info see Documentation/power/runtime_pm.txt).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc_rescan() checks whether registered cards are still present before
skipping them, by calling the bus-specific ->detect() handler.
With buses that support runtime PM, the card may be powered off at
this point, so they need to be powered on and fully reinitialized before
->detect() executes.
This whole process is redundant with nonremovable cards; in those cases,
we can safely skip calling ->detect() and implicitly assume its success.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
JMicron 388 SD/MMC combo controller supports the 1.8V low-voltage for
SD, but MMC doesn't work with the low-voltage, resulting in an error
at probing.
This patch adds the support for multiple voltage mask per device type,
so that SD works with 1.8V while MMC forces 3.3V. Here new ocr_avail_*
fields for each device are introduced, so that the actual OCR mask is
switched dynamically.
Also, the restriction of low-voltage in core/sd.c is removed when the
bit is allowed explicitly via ocr_avail_sd mask.
This patch was rewritten from scratch based on Aries' original code.
Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch modifies the MMC core code to optionally call the set_ios()
operation on the driver with the clock frequency set to 0 (gate) after
a grace period of at least 8 MCLK cycles, then restore it (ungate)
before any new request. This gives the driver the option to shut down
the MCI clock to the MMC/SD card when the clock frequency is 0, i.e.
the core has stated that the MCI clock does not need to be generated.
It is inspired by existing clock gating code found in the OMAP and
Atmel drivers and brings this up to the host abstraction. Gating is
performed before and after any MMC request.
This patchset implements this for the MMCI/PL180 MMC/SD host controller,
but it should be simple to switch OMAP/Atmel over to using this instead.
mmc_set_{gated,ungated}() add variable protection to the state holders
for the clock gating code. This is particularly important when ordinary
.set_ios() calls would race with the .set_ios() call resulting from a
delayed gate operation.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
usb: don't use flush_scheduled_work()
speedtch: don't abuse struct delayed_work
media/video: don't use flush_scheduled_work()
media/video: explicitly flush request_module work
ioc4: use static work_struct for ioc4_load_modules()
init: don't call flush_scheduled_work() from do_initcalls()
s390: don't use flush_scheduled_work()
rtc: don't use flush_scheduled_work()
mmc: update workqueue usages
mfd: update workqueue usages
dvb: don't use flush_scheduled_work()
leds-wm8350: don't use flush_scheduled_work()
mISDN: don't use flush_scheduled_work()
macintosh/ams: don't use flush_scheduled_work()
vmwgfx: don't use flush_scheduled_work()
tpm: don't use flush_scheduled_work()
sonypi: don't use flush_scheduled_work()
hvsi: don't use flush_scheduled_work()
xen: don't use flush_scheduled_work()
gdrom: don't use flush_scheduled_work()
...
Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
Workqueue creation API has been updated and flush_scheduled_work() is
deprecated and scheduled to be removed.
* core/core.c: Use alloc_ordered_workqueue() instead of
create_singlethread_workqueue(). This removes an unnecessary
rescuer.
* host/omap.c: Create, use and flush mmc_omap_wq instead of the
system_wq.
* Flush host->mmc_carddetect_work directly on removal instead of using
flush_scheduled_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Ball <cjb@laptop.org>
Cc: linux-mmc@vger.kernel.org
In the error-path where PM notifies PM_POST_RESTORE, the rescan-blockage
should be cleared as well. Otherwise it'll be never re-probed.
Also, as a bonus, this fixes a bug in S4 with user-mode suspend in the
current code, as it sends PM_POST_RESTORE instead of
PM_POST_HIBERNATION wrongly.
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some board/card/host configurations are not capable of powering off the
card after boot.
To support such configurations, and to allow smoother transition to
runtime PM behavior, MMC_CAP_POWER_OFF_CARD is added, so hosts need to
explicitly indicate whether it's OK to power off their cards after boot.
SDIO core will enable runtime PM for a card only if that cap is set.
As a result, the card will be powered down after boot, and will only
be powered up again when a driver is loaded (and then it's up to the
driver to decide whether power will be kept or not).
This will prevent sdio_bus_probe() failures with setups that do not
support powering off the card.
Reported-and-tested-by: Daniel Drake <dsd@laptop.org>
Reported-and-tested-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Power off the card in mmc_sdio_detect __before__ a potential error
handler, which completely removes the card, executes, and only if the
card was successfully powered on beforehand.
While we're at it, use the _sync variant of the runtime PM put API, in
order to ensure that the card is left powered off in case an error
occurred, and the card is going to be removed.
Reproduced and tested on the OLPC XO-1.5.
Reported-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
MMC hosts that poll for card detection by defining the MMC_CAP_NEEDS_POLL
flag have a race on rmmod, where the delayed work is cancelled without
waiting for completed polling. To prevent this a _sync version of the work
cancellation has to be used.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
We should not call mmc_card_set_ddr_mode() if we are in single data
mode. This sets DDR and causes the kernel log to say the card is DDR
when it is not.
Explicitly set ddr to 0 rather then rely on MMC_SDR_MODE being 0 when
doing the checks.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
For debugging power management features it is convenient to have the
possibility of changing the MMC host controller clock at runtime. This
patch adds a 'clock' file for this under the MMC host root of debugfs.
Usage is as follows:
# cat /sys/kernel/debug/mmc0/clock
52000000
# echo "1000000000" > /sys/kernel/debug/mmc0/clock
# cat /sys/kernel/debug/mmc0/clock
52000000
# echo "48000000" > /sys/kernel/debug/mmc0/clock
# cat /sys/kernel/debug/mmc0/clock
48000000
The middle example shows limits being applied by the host driver.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
[cjb: modify changelog language]
Signed-off-by: Chris Ball <cjb@laptop.org>
Bring SDIO devices back to full power before their suspend
handler is invoked.
Doing so ensures that SDIO suspend/resume semantics are
maintained (drivers still get to decide whether their
card should be removed or kept during system suspend,
and at what power state), and that SDIO suspend/resume
execution paths are unchanged.
This is achieved by resuming a runtime-suspended SDIO device
in its ->prepare() PM callback (similary to the PCI subsystem).
Since the PM core always increments the run-time usage
counter before calling the ->prepare() callback and decrements
it after calling the ->complete() callback, it is guaranteed
that when the system will come out of suspend, our device's
power state will reflect its runtime PM usage counter.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
To prevent an erroneous removal of the card, make sure
the device is powered when it is mmc_sdio_detect()ed.
This is required since mmc_sdio_detect may be invoked
while the device is runtime suspended (e.g., MMC core
is rescanning when system comes out of suspend).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Enable runtime PM for SDIO functions.
SDIO functions are initialized with a disabled runtime PM state,
and are set active (and their usage count is incremented)
only before potential drivers are probed.
SDIO function drivers that support runtime PM should call
pm_runtime_put_noidle() in their probe routine, and
pm_runtime_get_noresume() in their remove routine (very
similarly to PCI drivers).
In case a matching driver does not support runtime PM, power will
always be kept high (since the usage count is positive).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Enable runtime PM for new SDIO cards.
As soon as the card will be added to the device tree, runtime PM core
will release its power, since it doesn't have any users yet.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Assign the generic runtime PM handlers for SDIO.
These handlers invoke the relevant SDIO function drivers'
handlers, if exist, otherwise they just return success
(so SDIO drivers don't have to define any runtime PM handlers
unless they need to).
Runtime PM is still disabled by default, so this patch alone
has no immediate effect.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add MMC runtime PM handlers, which call mmc_power_save_host
and mmc_power_restore_host in response to runtime_suspend and
runtime_resume events.
Runtime PM is still disabled by default, so this patch alone
has no immediate effect.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add a power_restore handler to the SDIO bus ops,
in order to support waking up SDIO cards that
were powered off by runtime pm.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Allow power save/restore and their relevant mmc_bus_ops handlers
exit with a return value.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
On resume, let mmc_sdio_init_card go all the way, instead
of skipping the reconfiguration of the card's speed and width.
This is needed to ensure cards wake up with their clock
reconfigured (otherwise it's kept low).
This patch also removes the explicit bus width reconfiguration
on resume, since now this is part of mmc_sdio_init_card.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
One flaw with DDR support is that MMC core does not inform the driver
which DDR mode it has selected. This patch expands the ios->ddr flag
to do that.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
