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285814 commits

Author SHA1 Message Date
Rusty Russell
ee7cd8981e virtio: expose added descriptors immediately.
A virtio driver does virtqueue_add_buf() multiple times before finally
calling virtqueue_kick(); previously we only exposed the added buffers
in the virtqueue_kick() call.  This means we don't need a memory
barrier in virtqueue_add_buf(), but it reduces concurrency as the
device (ie. host) can't see the buffers until the kick.

In the unusual (but now possible) case where a driver does add_buf()
and get_buf() without doing a kick, we do need to insert one before
our counter wraps.  Otherwise we could wrap num_added, and later on
not realize that we have passed the marker where we should have
kicked.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:43 +10:30
Rusty Russell
3b720b8c86 virtio: avoid modulus operation.
Since we know vq->vring.num is a power of 2, modulus is lazy (it's asserted
in vring_new_virtqueue()).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:43 +10:30
Rusty Russell
41f0377f73 virtio: support unlocked queue kick
Based on patch by Christoph for virtio_blk speedup:

	Split virtqueue_kick to be able to do the actual notification
	outside the lock protecting the virtqueue.  This patch was
	originally done by Stefan Hajnoczi, but I can't find the
	original one anymore and had to recreated it from memory.
	Pointers to the original or corrections for the commit message
	are welcome.

Stefan's patch was here:

	a6d06644e3
	http://www.spinics.net/lists/linux-virtualization/msg14616.html

Third time's the charm!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:43 +10:30
Rusty Russell
f96fde41f7 virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2012-01-12 15:44:42 +10:30
Rusty Russell
5dfc17628d virtio: document functions better.
The old documentation is left over from when we used a structure with
strategy pointers.

And move the documentation to the C file as per kernel practice.
Though I disagree...

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2012-01-12 15:44:42 +10:30
Sasha Levin
1e214a5c1a virtio-balloon: Trivial cleanups
Trivial changes to remove forgotten junk, format comments, and correct names.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:42 +10:30
Rusty Russell
7b21e34fd1 virtio: harsher barriers for rpmsg.
We were cheating with our barriers; using the smp ones rather than the
real device ones.  That was fine, until rpmsg came along, which is
used to talk to a real device (a non-SMP CPU).

Unfortunately, just putting back the real barriers (reverting
d57ed95d) causes a performance regression on virtio-pci.  In
particular, Amos reports netbench's TCP_RR over virtio_net CPU
utilization increased up to 35% while throughput went down by up to
14%.

By comparison, this branch is in the noise.

Reference: https://lkml.org/lkml/2011/12/11/22

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:42 +10:30
Ulf Hansson
aa9df4fb2a mmc: core: Add option to prevent eMMC sleep command
Host may now use MMC_CAP2_NO_SLEEP_CMD to disable the use
of eMMC sleep/awake command.

This option can be used when your platform has a buggy
kernel crash dump software, which is supposed to store
the dump on the eMMC, but is not able to wake up the eMMC
from sleep state.

In particular, failures have been seen with u-boot; even if
it is fixed there, platforms will be slow to update their
bootloader binaries.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:48 -05:00
NeilBrown
7efab4f357 mmc: omap_hsmmc: use threaded irq handler for card-detect.
As the card-detect irq handler just schedules work to be done by a
thread, we can use request_threaded_irq to do much of the work for
us.  This means that interrupts which arrive by handle_nested_irq
actually work.

Reviewed-by: Felipe Balbi <balbi@ti.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Kishore Kadiyala <kishorek.kadiyala@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:48 -05:00
Adrian Hunter
93933508ce mmc: sdhci-pci: enable runtime PM for Medfield SDIO
Runtime PM for SDIO is no longer enabled by default (see
5c7f0e083d) so it must now
be enabled per platform, in this case Medfield uses it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:48 -05:00
Todd Poynor
30832ab56c mmc: sdhci: Always pass clock request value zero to set_clock host op
To allow the set_clock host op to disable the SDCLK source when not
needed, always call the host op when the requested clock speed is
zero.  Do this even if host->clock already equals zero, because
the SDHCI driver may set that value (without calling the host op)
to force an update at the next (non-zero-speed) call.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Adrian Hunter
e2a0a5829c mmc: sdhci-pci: remove SDHCI_QUIRK2_OWN_CARD_DETECTION
Even if a driver provides separate card detection, an interrupt
is still needed to abort mmc requests that are in progress.
SDHCI_QUIRK2_OWN_CARD_DETECTION prevents that, so remove it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Adrian Hunter
c5e027a4a1 mmc: sdhci-pci: get gpio numbers from platform data
Retrieve the GPIO numbers for hardware reset and
card detect from platform data.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Adrian Hunter
52c506f0bc mmc: sdhci-pci: add platform data
Add a means of getting platform data for the SDHCI PCI
devices.  The data is stored against the slot not the
device in order to support multi-slot devices.

The data allows platform-specific setup (such as getting
GPIO numbers from firmware or setting up wl12xx for SDIO)
to be done in platform support files instead of the
sdhci-pci driver.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Adrian Hunter
c79396c191 mmc: sdhci: prevent card detection activity for non-removable cards
Do not enable card detection interrupts for non-removable cards.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Adrian Hunter
ceb6143b2d mmc: sdhci: fix vmmc handling
Presently the vmmc regulator is enabled when the host
controller is added and disabled when it is removed.
However, the vmmc regulator should be under the control
of the upper layers via ->set_ios().  Make it so.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:47 -05:00
Seungwon Jeon
17e9ff559a mmc: core: Add claiming of hosts during mmc_cache_ctrl
While calling mmc_cache_ctrl() a host is not claimed. This patch
adds the mmc_try_claim_host() for quick response in suspend.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:46 -05:00
Balaji TK
d83b6e035f mmc: omap: remove clock rate hard coding
MMC master clock rate can vary for each instance of the MMC controller
on the device. Use clk_get_rate instead to get the value.

Signed-off-by: Balaji TK  <balajitk@ti.com>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:46 -05:00
Guennadi Liakhovetski
699834045f mmc: sh_mmcif: remove now superfluous sh_mmcif_host::data member
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:46 -05:00
Guennadi Liakhovetski
f985da17f4 mmc: sh_mmcif: process requests asynchronously
This patch converts the sh_mmcif MMC host driver to process requests
asynchronously instead of waiting in its .request() method for completion.
This is achieved by using threaded IRQs.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:46 -05:00
Guennadi Liakhovetski
ee4b88879f mmc: sh_mmcif: cosmetic clean up
This patch doesn't introduce any functional changes, it only simplifies
some code fragments, removes superfluous parameters, fixes typos.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:46 -05:00
Guennadi Liakhovetski
8a8284a98c mmc: sh_mmcif: process error interrupts first
If an interrupt is coming with both error and data completion status bits
set, it has to be handled as an error interrupt, for which error interrupts
have to be processed first. The current version of the driver on the
contrary doesn't recognise such interrupts as an error event, which leads
to data corruption and breaks the error recovery.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Guennadi Liakhovetski
349ab52446 mmc: add a generic GPIO card-detect helper
This patch adds a primitive helper to support card hotplug detection on
platforms, where a GPIO, capable of producing interrupts, is used for
detection of card-insertion and -removal events.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Guennadi Liakhovetski
b67e198073 mmc: add a card hotplug handler context
SD/MMC controllers provide different card insertion and removal detection
methods. On some of them the controller itself issues an interrupt, on
others polling is used, on yet others auxiliary means are used for this
purpose, e.g., a GPIO IRQ. Further, on some systems one of those methods
can be chosen at driver probing time and configured in software. E.g., on
some systems the SD/MMC controller card hot-plug detection pin can be
configured either as a respective controller functions, or an IRQ-capable
GPIO. To support such flexible configurations a card hot-plug context
is added by this patch.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Bastian Hecht
cbb18b309d mmc: tmio_mmc: Hotplug code regrouping
This patch regroups the code slightly, adds documentation and allows
the rtpm counter of MMC_CAP_NEEDS_POLL devices to reach 0 again.

Signed-off-by: Bastian Hecht <hechtb@gmail.com>
[g.liakhovetski@gmx.de: restore pm_runtime_get_noresume()]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Girish K S
913047e9e5 mmc: core: Fix voltage select in DDR mode
This patch fixes the wrong comparison before setting the interface
voltage in DDR mode.

The assignment to the variable ddr before comaprison is either
ddr = MMC_1_2V_DDR_MODE; or ddr == MMC_1_8V_DDR_MODE. But the comparison
is done with the extended csd value if ddr == EXT_CSD_CARD_TYPE_DDR_1_2V.

Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Acked-by: Subhash Jadavani <subhashj@codeaurora.org>
Acked-by: Philip Rakity <prakity@marvell.com>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Jingoo Han
7003fecbf0 mmc: sdhci-s3c: use S3C_SDHCI_CONTROL2 instead of hardcoded offset value
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:45 -05:00
Seungwon Jeon
053b3ce6c1 mmc: dw_mmc: Support predefined mutiple block transfers
This patch adds the support for predefined multiple block r/w.
dw_mmc can support MMC_CAP_CMD23 capability.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00
Chris Ball
5b93a4595b mmc: dw_mmc: Remove unnecessary else clauses
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00
Seungwon Jeon
4f408cc67a mmc: dw_mmc: Add more capabilities field
This patch adds another capabilities field for MMC_CAPS2_XXX.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00
Jaehoon Chung
6fe8890d02 mmc: dw_mmc: use dev_pm_ops for dw_mmc controllers
This patch modifies dw_mmc to use dev_pm_ops.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00
Sujit Reddy Thumma
a8ad82cc1b mmc: card: Kill block requests if card is removed
Kill block requests when the host realizes that the card is
removed from the slot and is sure that subsequent requests
are bound to fail. Do this silently so that the block
layer doesn't output unnecessary error messages.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00
Stephen Boyd
4137e50494 mmc: core: Fixup delayed work clock gating patch
c31b50e (mmc: core: Use delayed work in clock gating framework,
2011-11-14) missed a few things during review:

 o A useless pr_info()

 o milliseconds was written as two words

 o The sysfs file had units in its output

Fix all three problems.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Axel Lin
b678b91f22 mmc: sdhci-pci: simplify error handling
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Johan Rudholm
add710eaa8 mmc: boot partition ro lock support
Enable boot partitions to be read-only locked until next power on via
a sysfs entry. There will be one sysfs entry for each boot partition:

/sys/block/mmcblkXbootY/ro_lock_until_next_power_on

Each boot partition is locked by writing 1 to its file.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: John Beckett <john.beckett@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Sangwook Lee
92df954df3 ARM: SAMSUNG: Add pm_caps into platform data
Add pm_caps into platform_data. This is power management, usually
for SDIO device such as SDIO WLAN.

Signed-off-by: Sangwook Lee <sangwook.lee@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Sangwook Lee
fa1773cc5b mmc: sdhci-s3c: Add pm_caps into SD/MMC host
sdhci-s3c updates pm_caps from platform data for SDIO PM.

Signed-off-by: Sangwook Lee <sangwook.lee@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Adrian Hunter
d304950488 mmc: allow upper layers to know immediately if card has been removed
Add a function mmc_detect_card_removed() which upper layers can use to
determine immediately if a card has been removed. This function should
be called after an I/O request fails so that all queued I/O requests
can be errored out immediately instead of waiting for the card device
to be removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:43 -05:00
Cong Wang
482fce997e mmc: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:42 -05:00
Axel Lin
d1f81a64a4 mmc: convert drivers/mmc/host/* to use module_platform_driver()
This patch converts the drivers in drivers/mmc/host/* 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: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Acked-by: David Brown <davidb@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:42 -05:00
Lars-Peter Clausen
6601056a96 mmc: Remove redundant spi driver bus initialization
In ancient times it was necessary to manually initialize the bus field of an
spi_driver to spi_bus_type. These days this is done in spi_driver_register(),
so we can drop the manual assignment.

The patch was generated using the following coccinelle semantic patch:
// <smpl>
@@
identifier _driver;
@@
struct spi_driver _driver = {
	.driver = {
-		.bus = &spi_bus_type,
	},
};
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:42 -05:00
Guennadi Liakhovetski
86df174585 mmc: sh_mmcif: simplify clock divisor calculation
Replace ilog2(__rounddown_pow_of_two(x)) with the equivalent but much
simpler fls(x) - 1.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:42 -05:00
Johan Rudholm
4d6144de8b mmc: core: check for zero length ioctl data
If the read or write buffer size associated with the command sent
through the mmc_blk_ioctl is zero, do not prepare data buffer.

This enables a ioctl(2) call to for instance send a MMC_SWITCH to set
a byte in the ext_csd.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:42 -05:00
Tony Lin
4ee5ebaf74 mmc: sdhci-esdhc: Change delay after setting clock from 100ms to 1ms
1ms is enough for hardware to change the clock to stable.
100ms is too long in the tasklet.

Signed-off-by: Tony Lin <tony.lin@freescale.com>
CC: Xiaobo Xie <X.Xie@freescale.com>
CC: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Per Forlin
739c69c964 mmc: mmc_test: align max_seg_size
If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
sizes that are not aligned with 512 byte. Fix, align max_seg_size at
mmc_test_area_init().

Signed-off-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Per Forlin
5a09262744 mmc: mmci: add capabilities2 for MMC_CAP2
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Philip Rakity
a303c5319c mmc: sdio: support SDIO UHS cards
This patch adds support for sdio UHS cards per the version 3.0
spec.

UHS mode is only enabled for version 3.0 cards when both the
host and the controller support UHS modes.

1.8v signaling support is removed if both the card and the
host do not support UHS.  This is done to maintain
compatibility and some system/card combinations break when
1.8v signaling is enabled when the host does not support UHS.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Aaron Lu <Aaron.lu@amd.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Tested-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Viresh Kumar
b70a7fab26 mmc: sdhci-spear: Implement suspend/resume
Suspend/Resume is missing from sdhci-spear driver. This patch adds
support for suspend/resume for this driver.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Sujit Reddy Thumma
597dd9d79c mmc: core: Use delayed work in clock gating framework
Current clock gating framework disables the MCI clock as soon as the
request is completed and enables it when a request arrives. This aggressive
clock gating framework, when enabled, cause following issues:

When there are back-to-back requests from the Queue layer, we unnecessarily
end up disabling and enabling the clocks between these requests since 8MCLK
clock cycles is a very short duration compared to the time delay between
back to back requests reaching the MMC layer. This overhead can effect the
overall performance depending on how long the clock enable and disable
calls take which is platform dependent. For example on some platforms we
can have clock control not on the local processor, but on a different
subsystem and the time taken to perform the clock enable/disable can add
significant overhead.

Also if the host controller driver decides to disable the host clock too
when mmc_set_ios function is called with ios.clock=0, it adds additional
delay and it is highly possible that the next request had already arrived
and unnecessarily blocked in enabling the clocks. This is seen frequently
when the processor is executing at high speeds and in multi-core platforms
thus reduces the overall throughput compared to if clock gating is
disabled.

Fix this by delaying turning off the clocks by posting request on
delayed workqueue. Also cancel the unscheduled pending work, if any,
when there is access to card.

sysfs entry is provided to tune the delay as needed, default
value set to 200ms.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:41 -05:00
Chris Ball
c59d44739a mmc: card: Use manufacturer ID symbols in card quirks.
No functional change; adds macros for card manufacturer IDs.

Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: Andrei E. Warkentin <andrey.warkentin@gmail.com>
Cc: Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com>
2012-01-11 23:58:40 -05:00