litmus-rt-ext-res.git/Documentation/mmc, branch EXT-RES

mmc: core: Extend sysfs with DSR register

2016-07-25T08:34:51+00:00

Export DSR register through sysfs same as we did for the CID, CSD and
OCR registers.

Signed-off-by: Bojan Prtvar 
Signed-off-by: Ulf Hansson

mmc: core: Extend sysfs with OCR register

2016-07-25T08:34:48+00:00

Registers CID and CSD are already exported through sysfs so let's make
this interface complete by adding missing OCR register.

Signed-off-by: Bojan Prtvar 
Reviewed-by: Wolfram Sang 
Signed-off-by: Ulf Hansson

Documentation: mmc: Add the introduction for mmc-utils

2016-03-31T06:54:22+00:00

This patch introduces one mmc test tools called mmc-utils, which is convenient
if someone wants to exercise and test MMC/SD devices from userspace.

Signed-off-by: Baolin Wang 
Signed-off-by: Jonathan Corbet

mmc: core: Remove MMC_CLKGATE

2015-10-26T15:00:09+00:00

MMC_CLKGATE was once invented to save power by gating the bus clock at
request inactivity. At that time it served its purpose. The modern way to
deal with power saving for these scenarios, is by using runtime PM.

Nowadays, several host drivers have deployed runtime PM, but for those
that haven't and which still cares power saving at request inactivity,
it's certainly time to deploy runtime PM as it has been around for several
years now.

To simplify code to mmc core and thus decrease maintenance efforts, this
patch removes all code related to MMC_CLKGATE.

Signed-off-by: Ulf Hansson 
Reviewed-by: Linus Walleij

mmc: core: Add in support to expose PRV for v4 MMCs

2013-03-22T16:10:42+00:00

The JEDEC MMC v4 spec defines a new PRV value in place of the original
fwrev and hwrev specified in v1. We can expose this in the kernel to enable
user space to more easily determine the product revision of a given MMC.

Signed-off-by: Bernie Thompson 
Reviewed-by: Ulf Hansson 
Signed-off-by: Chris Ball

mmc: core: Extend sysfs to ext_csd parameters for RPMB support

2012-12-06T18:54:48+00:00

Extend current sysfs access to ext_csd rpmb parameters (RPMB partition
size) and rel_sector information.

Signed-off-by: Loic Pallardy 
Reviewed-by: Namjae Jeon 
Acked-by: Linus Walleij 
Acked-by: Johan Rudholm 
Acked-by: Krishna Konda 
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: boot partition ro lock support

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

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 
Signed-off-by: John Beckett 
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

mmc: documentation of mmc non-blocking request usage and design.

2011-07-21T14:34:52+00:00

Documentation about the background and the design of mmc non-blocking.
Host driver guidelines to minimize request preparation overhead.

Signed-off-by: Per Forlin 
Acked-by: Randy Dunlap 
Signed-off-by: Chris Ball