linux-stable.git/include/linux/mmc, branch linux-5.1.y

mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

2019-06-25T03:34:44+00:00

commit b4c9f938d542d5f88c501744d2d12fad4fd2915f upstream.

We want SDIO drivers to be able to temporarily stop retuning when the
driver knows that the SDIO card is not in a state where retuning will
work (maybe because the card is asleep).  We'll move the relevant
functions to a place where drivers can call them.

Cc: stable@vger.kernel.org #v4.18+
Signed-off-by: Douglas Anderson 
Acked-by: Adrian Hunter 
Acked-by: Kalle Valo 
Signed-off-by: Ulf Hansson 
Signed-off-by: Greg Kroah-Hartman

mmc: core: API to temporarily disable retuning for SDIO CRC errors

2019-06-25T03:34:44+00:00

commit 0a55f4ab9678413a01e740c86e9367ba0c612b36 upstream.

Normally when the MMC core sees an "-EILSEQ" error returned by a host
controller then it will trigger a retuning of the card.  This is
generally a good idea.

However, if a command is expected to sometimes cause transfer errors
then these transfer errors shouldn't cause a re-tuning.  This
re-tuning will be a needless waste of time.  One example case where a
transfer is expected to cause errors is when transitioning between
idle (sometimes referred to as "sleep" in Broadcom code) and active
state on certain Broadcom WiFi SDIO cards.  Specifically if the card
was already transitioning between states when the command was sent it
could cause an error on the SDIO bus.

Let's add an API that the SDIO function drivers can call that will
temporarily disable the auto-tuning functionality.  Then we can add a
call to this in the Broadcom WiFi driver and any other driver that
might have similar needs.

NOTE: this makes the assumption that the card is already tuned well
enough that it's OK to disable the auto-retuning during one of these
error-prone situations.  Presumably the driver code performing the
error-prone transfer knows how to recover / retry from errors.  ...and
after we can get back to a state where transfers are no longer
error-prone then we can enable the auto-retuning again.  If we truly
find ourselves in a case where the card needs to be retuned sometimes
to handle one of these error-prone transfers then we can always try a
few transfers first without auto-retuning and then re-try with
auto-retuning if the first few fail.

Without this change on rk3288-veyron-minnie I periodically see this in
the logs of a machine just sitting there idle:
  dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ

Cc: stable@vger.kernel.org #v4.18+
Signed-off-by: Douglas Anderson 
Acked-by: Adrian Hunter 
Acked-by: Kalle Valo 
Signed-off-by: Ulf Hansson 
Signed-off-by: Greg Kroah-Hartman

mmc: core: Add discard support to sd

2019-02-28T08:16:12+00:00

SD spec v5.1 adds discard support. The flows and commands are similar to
mmc, so just set the discard arg in CMD38.

A host which supports DISCARD shall check if the DISCARD_SUPPORT (b313)
is set in the SD_STATUS register.  If the card does not support discard,
the host shall not issue DISCARD command, but ERASE command instead.

Post the DISCARD operation, the card may de-allocate the discarded
blocks partially or completely. So the host mustn't make any assumptions
concerning the content of the discarded region. This is unlike ERASE
command, in which the region is guaranteed to contain either '0's or
'1's, depends on the content of DATA_STAT_AFTER_ERASE (b55) in the scr
register.

One more important difference compared to ERASE is the busy timeout
which we will address on the next patch.

Signed-off-by: Avri Altman 
Signed-off-by: Ulf Hansson

mmc: core: Convert mmc_regulator_get_ocrmask() to static

2019-02-25T14:20:58+00:00

The only left user of mmc_regulator_get_ocrmask() is the mmc core itself.
Therefore, let's drop the export and turn it into static.

Signed-off-by: Ulf Hansson

mmc: core: Move regulator helpers to separate file

2019-02-25T14:20:58+00:00

The mmc regulator helper functions, are placed in the extensive core.c
file.  In a step towards trying to create a better structure of files,
avoiding too many lines of code per file, let's move these helpers to a new
file, regulator.c.

Moreover, this within this context it makes sense to also drop the export
of mmc_vddrange_to_ocrmask(), but instead let's make it internal to the mmc
core.

Signed-off-by: Ulf Hansson

mmc: core: Indicate SD specs higher than 4.0

2019-02-25T07:40:58+00:00

SD specs version 4.x and 5.x have a dedicated slices in the SCR register.
Higher versions will rely on a combination of the existing fields.

Signed-off-by: Avri Altman 
Signed-off-by: Ulf Hansson

mmc: core: Calculate the discard arg only once

2019-02-25T07:40:58+00:00

In MMC, the discard arg is a read-only ext_csd parameter - set it once
on card init. To be consistent, do that for SD as well even though its
discard arg is always 0x0.

Signed-off-by: Avri Altman 
Signed-off-by: Ulf Hansson

mmc: slot-gpio: Remove override_active_level on WP

2019-02-25T07:40:58+00:00

The argument "override_active_level" made it possible to
enforce a specific polarity on the write-protect
GPIO line. All callers in the kernel pass "false" to this
call after I have converted all drivers to use GPIO machine
descriptors, so remove the argument and clean out this.

This kind of polarity inversion should be handled by the
GPIO descriptor inside the GPIO library if needed.

This rids us of one instance of the kludgy calls into
the gpiod_get_raw_value() API.

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

mmc: bcm2835: Drop pointer to mmc_host from bcm2835_host

2019-02-25T07:40:58+00:00

The BCM2835 MMC host driver uses a pointer to get from the private
bcm2835_host structure to the generic mmc_host structure.  However the
latter is always immediately preceding the former in memory, so compute
its address with a subtraction (which is cheaper than a dereference) and
drop the superfluous pointer.

No functional change intended.

Signed-off-by: Lukas Wunner 
Cc: Frank Pavlic 
Cc: Alexander Graf 
Reviewed-by: Alexander Graf 
Signed-off-by: Ulf Hansson

mmc: block: handle complete_work on separate workqueue

2019-02-08T11:24:17+00:00

The kblockd workqueue is created with the WQ_MEM_RECLAIM flag set.
This generates a rescuer thread for that queue that will trigger when
the CPU is under heavy load and collect the uncompleted work.

In the case of mmc, this creates the possibility of a deadlock when
there are multiple partitions on the device as other blk-mq work is
also run on the same queue. For example:

- worker 0 claims the mmc host to work on partition 1
- worker 1 attempts to claim the host for partition 2 but has to wait
  for worker 0 to finish
- worker 0 schedules complete_work to release the host
- rescuer thread is triggered after time-out and collects the dangling
  work
- rescuer thread attempts to complete the work in order starting with
  claim host
- the task to release host is now blocked by a task to claim it and
  will never be called

The above results in multiple hung tasks that lead to failures to
mount partitions.

Handling complete_work on a separate workqueue avoids this by keeping
the work completion tasks separate from the other blk-mq work. This
allows the host to be released without getting blocked by other tasks
attempting to claim the host.

Signed-off-by: Zachary Hays 
Fixes: 81196976ed94 ("mmc: block: Add blk-mq support")
Cc: 
Signed-off-by: Ulf Hansson