linux-toradex.git/drivers/mmc/core/host.c, branch v3.4.2

mmc: start removing enable / disable API

2012-03-27T16:20:03+00:00

Most parts of the enable / disable API are no longer used and
can be removed.

Signed-off-by: Adrian Hunter 
Tested-by: Venkatraman S 
Tested-by: Jaehoon Chung 
Signed-off-by: Chris Ball

mmc: core: fix regression: set default clock gating delay to 0

2012-03-04T17:18:40+00:00

A recent commit "mmc: core: Use delayed work in clock gating framework"
(597dd9d79cfbbb1) introduced a default 200ms delay before clock gating
actually takes place.  This means that every time an MMC interface
becomes idle it first stays on for 200ms before gating its clock. This
leads to increased power consumption and is therefore a clear regression.
This patch restores the original behaviour by setting the default delay
to 0. Users prioritising throughput over power efficiency can still
modify the delay via sysfs.

Signed-off-by: Guennadi Liakhovetski 
Signed-off-by: Chris Ball

mmc: core: Fixup delayed work clock gating patch

2012-01-12T04:58:43+00:00

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 
Cc: Sujit Reddy Thumma 
Signed-off-by: Chris Ball

mmc: core: Use delayed work in clock gating framework

2012-01-12T04:58:41+00:00

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 
Acked-by: Linus Walleij 
Signed-off-by: Chris Ball

Revert "mmc: enable runtime PM by default"

2011-12-19T23:51:38+00:00

When SDIO runtime PM was originally introduced, we immediately faced
two regressions with two different chipsets, and in response decided
not to enable it by default.

With the recent work on the 8686 we hoped we found all the gotchas,
so 08da834 did make sense (at least experimentally).

Unfortunately we now see that some setups out there still refuse to
work when SDIO runtime PM is enabled by default (see
http://www.spinics.net/lists/linux-mmc/msg11161.html), and obviously
we can't live with these kind of regressions.

This reverts commit 08da834a24312157f512224691ad1fddd11c1073.

Signed-off-by: Ohad Ben-Cohen 
Cc: Daniel Drake 
Signed-off-by: Chris Ball

mmc: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required

2011-10-31T23:32:06+00:00

These two basic defines were everywhere, simply because module.h
was also everywhere.   But we are cleaning up the latter.  So make
the exporters actually call out their need for the include.

Signed-off-by: Paul Gortmaker

mmc: enable runtime PM by default

2011-10-26T19:43:35+00:00

Now that we have improved the runtime power management powerup/powerdown
code, we believe that MMC_CAP_POWER_OFF_CARD is no longer necessary:
runtime PM should now work everywhere.

The only hard evidence for introducing MMC_CAP_POWER_OFF_CARD was the
Marvell sd8686 wifi chip, which was believed to require external gpio
manipulation which wasn't supported by some boards.

After further investigation it was realized (and confirmed by Marvell
folks) that sd8686 requirements can be fulfilled by changing the reset
sequence itself, even if no external gpio is manipulated.

For further information, see the following thread:
http://www.mail-archive.com/linux-mmc@vger.kernel.org/msg04289.html

Enable this trivially for a release or two. If no problems are reported,
we will follow up with a more extensive patch to remove this flag
altogether. If problems are reported, we can look at whitelist/blacklist
possibilities as before.

Signed-off-by: Daniel Drake 
Acked-by: Ohad Ben-Cohen 
Signed-off-by: Chris Ball

mmc: core: use non-reentrant workqueue for clock gating

2011-08-31T20:25:50+00:00

The default multithread workqueue can cause the same work to be executed
concurrently on a different CPUs. This isn't really suitable for clock
gating as it might already gated the clock and gating it twice results both
host->clk_old and host->ios.clock to be set to 0.

To prevent this from happening we use system_nrt_wq instead.

Signed-off-by: Mika Westerberg 
Reviewed-by: Linus Walleij 
Tested-by: Chris Ball 
Cc: 
Signed-off-by: Chris Ball

mmc: rename mmc_host_clk_{ungate|gate} to mmc_host_clk_{hold|release}

2011-08-31T20:24:54+00:00

As per suggestion by Linus Walleij:

  > If you think the names of the functions are confusing then
  > you may rename them, say like this:
  >
  > mmc_host_clk_ungate() -> mmc_host_clk_hold()
  > mmc_host_clk_gate() -> mmc_host_clk_release()
  >
  > Which would make the usecases more clear

(This is CC'd to stable@ because the next two patches, which fix
observable races, depend on it.)

Signed-off-by: Mika Westerberg 
Reviewed-by: Linus Walleij 
Cc: 
Signed-off-by: Chris Ball

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc

2011-05-25T23:55:55+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (75 commits)
  mmc: core: eMMC bus width may not work on all platforms
  mmc: sdhci: Auto-CMD23 fixes.
  mmc: sdhci: Auto-CMD23 support.
  mmc: core: Block CMD23 support for UHS104/SDXC cards.
  mmc: sdhci: Implement MMC_CAP_CMD23 for SDHCI.
  mmc: core: Use CMD23 for multiblock transfers when we can.
  mmc: quirks: Add/remove quirks conditional support.
  mmc: Add new VUB300 USB-to-SD/SDIO/MMC driver
  mmc: sdhci-pxa: Add quirks for DMA/ADMA to match h/w
  mmc: core: duplicated trial with same freq in mmc_rescan_try_freq()
  mmc: core: add support for eMMC Dual Data Rate
  mmc: core: eMMC signal voltage does not use CMD11
  mmc: sdhci-pxa: add platform code for UHS signaling
  mmc: sdhci: add hooks for setting UHS in platform specific code
  mmc: core: clear MMC_PM_KEEP_POWER flag on resume
  mmc: dw_mmc: fixed wrong regulator_enable in suspend/resume
  mmc: sdhi: allow powering down controller with no card inserted
  mmc: tmio: runtime suspend the controller, where possible
  mmc: sdhi: support up to 3 interrupt sources
  mmc: sdhi: print physical base address and clock rate
  ...