linux-toradex.git/drivers/mmc/core/sd.c, branch v4.10

mmc: sd: Meet alignment requirements for raw_ssr DMA

2016-12-21T07:34:30+00:00

The mmc_read_ssr() function results in DMA to the raw_ssr member of
struct mmc_card, which is not guaranteed to be cache line aligned & thus
might not meet the requirements set out in Documentation/DMA-API.txt:

  Warnings:  Memory coherency operates at a granularity called the cache
  line width.  In order for memory mapped by this API to operate
  correctly, the mapped region must begin exactly on a cache line
  boundary and end exactly on one (to prevent two separately mapped
  regions from sharing a single cache line).  Since the cache line size
  may not be known at compile time, the API will not enforce this
  requirement.  Therefore, it is recommended that driver writers who
  don't take special care to determine the cache line size at run time
  only map virtual regions that begin and end on page boundaries (which
  are guaranteed also to be cache line boundaries).

On some systems where DMA is non-coherent this can lead to us losing
data that shares cache lines with the raw_ssr array.

Fix this by kmalloc'ing a temporary buffer to perform DMA into. kmalloc
will ensure the buffer is suitably aligned, allowing the DMA to be
performed without any loss of data.

Signed-off-by: Paul Burton 
Fixes: 5275a652d296 ("mmc: sd: Export SD Status via “ssr” device attribute")
Cc: 
Signed-off-by: Ulf Hansson

mmc: core: remove BUG_ONs from sd

2016-12-05T09:31:10+00:00

BUG_ONs doesn't help anything except for stop the system from
running. If it occurs, it implies we should deploy proper error
handling for that. So this patch is gonna discard these meaningless
BUG_ONs and deploy error handling if needed.

Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson

mmc: sd: Export SD Status via “ssr” device attribute

2016-09-26T19:31:09+00:00

The SD Status register contains several important fields related to the
SD Card proprietary features.
Those fields may be used by user space applications for vendor specific
usage.
None of those fields are exported today by the driver to user space.
In this patch, we are reading the SD Status register and exporting
(using MMC_DEV_ATTR) the SD Status register to the user space.

Signed-off-by: Uri Yanai 
Signed-off-by: Ulf Hansson

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

mmc: core: remove redundant memset of mmc_decode_cid

2016-03-17T13:54:41+00:00

When initializing sd or sdio card, we get struct mmc_card
from mmc_alloc_card which allocates it by kzalloc. So we don't
need another memset while decoding cid.

Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson

mmc: core: Enable tuning according to the actual timing

2016-01-14T09:59:09+00:00

While in sdhci_execute_tuning() the choice whether or not to enable the
tuning is done on the actual timing, in the mmc_sdio_init_uhs_card() the
check is done on the capability of the card.

This difference is causing some issues with some SDIO cards in DDR50
mode where the CDM19 is wrongly issued.

With this patch we modify the check in both
mmc_(sd|sdio)_init_uhs_card() functions to take the proper decision
only according to the actual timing specification.

Cc: stable@vger.kernel.org
Signed-off-by: Carlo Caione 
Signed-off-by: Ulf Hansson

mmc: sd: limit SD card power limit according to cards capabilities

2016-01-13T09:56:27+00:00

The SD card specification allows cards to error out a SWITCH command
where the requested function in a group is not supported.  The spec
provides for a set of capabilities which indicate which functions are
supported.

In the case of the power limit, requesting an unsupported power level
via the SWITCH command fails, resulting in the power level remaining at
the power-on default of 0.72W, even though the host and card may support
higher powers levels.

This has been seen with SanDisk 8GB cards, which support the default
0.72W and 1.44W (200mA and 400mA) in combination with an iMX6 host,
supporting up to 2.88W (800mA).  This currently causes us to try to set
a power limit function value of '3' (2.88W) which the card errors out
on, and thereby causes the power level to remain at 0.72W rather than
the desired 1.44W.

Arrange to limit the selected current limit by the capabilities reported
by the card to avoid the SWITCH command failing.  Select the highest
current limit that the host and card combination support.

Signed-off-by: Russell King 
Fixes: a39ca6ae0a08 ("mmc: core: Simplify and fix for SD switch processing")
Signed-off-by: Ulf Hansson

mmc: It is not an error for the card to be removed while suspended

2015-12-28T11:51:38+00:00

A card can be removed while it is runtime suspended.
Do not print an error message.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: core: Make runtime resume default behavior for MMC/SD

2015-12-22T10:32:03+00:00

MMC_CAP_RUNTIME_RESUME was invented to decrease system PM resume time for
systems that particularly needs this. As the feature has matured let's
make it the default behavior for MMC/SD.

Signed-off-by: Ulf Hansson