[PATCH V6 00/15] mmc: host: Add facility to support re-tuning

Adrian Hunter
2015-04-20T12:12:10Z

Hi

Here is V6 of some patches to move re-tuning support
out of sdhci and into the core, and add support for HS400
re-tuning.

Currently sdhci does re-tuning transparently by
calling sdhci_execute_tuning() from its ->request()
function.

The problem with HS400 re-tuning is that it must be
done in HS200 mode. That means using switch commands
and making ios changes. That means it potentially
conflicts with other command sequences. The new
re-tuning support accomodates that.

Changes in V6:

mmc: host: Add facility to support re-tuning
Don't export functions only used in core

mmc: core: Enable / disable re-tuning
Ensure re-tuning timer is disabled in SDIO suspend

mmc: core: Hold re-tuning while bkops ongoing
Hold re-tuning always and release only if
bkops is not ongoing.

mmc: mmc: Hold re-tuning if the card is put to sleep
Hold re-tuning for mmc_sleep even if card is
immediately powered off, disabling re-tuning.

Changes in V5:

mmc: host: Add facility to support re-tuning
Make mmc_retune_enable() / mmc_retune_disable()
only called from core.

mmc: core: Enable / disable re-tuning
Replaces mmc: core: Disable re-tuning when card is no longer initialized
Enables re-tuning when tuning is executed

mmc: sdhci: Change to new way of doing re-tuning
Set host->retune_period instead of enabling re-tuning.

Changes in V4:

These patches now depend on Ulf's patch:
mmc: core: Enable runtime PM management of host devices

mmc: host: Add facility to support re-tuning

Assume mmc_claim_host() runtime resumes the host
controller so there are no races with runtime pm.
Consequently remove now un-needed re-tuning host
operations.

mmc: core: Add support for re-tuning before each request

Call mmc_retune() prior to ->request()

mmc: sdhci: Change to new way of doing re-tuning

Updated to reflect the changes above.

Changes in V3:

mmc: host: Add facility to support re-tuning

Add host->retune_now flag so re-tuning can be
started in the host drivers ->request()
function to avoid racing with Runtime PM.

Add host operations to let the host know when
re-tuning is held, for eaxmple, to enable
synchronization with runtime suspend / resume.

Ensure functions are exported.

mmc: core: Add support for re-tuning before each request
Updated to reflect the change above.

mmc: core: Check re-tuning before retrying
Updated to reflect the change above.

mmc: core: Hold re-tuning during switch commands
Updated to reflect the change above.

mmc: core: Hold re-tuning during erase commands
Updated to reflect the change above.

mmc: core: Hold re-tuning while bkops ongoing
Updated to reflect the change above.

mmc: core: Add support for HS400 re-tuning
Updated and as already sent separately as V3:
Remember to mmc_set_bus_speed(card) in mmc_hs400_to_hs200()

mmc: sdhci: Change to new way of doing re-tuning
Call mmc_retune() from ->request() function to
avoid racing with Runtime PM. And implement
hold_tuning / release_tuning operations to prevent
runtime suspend while re-tuning is held.

mmc: block: Retry errored data requests when re-tuning is needed
Updated and as already sent separately as V3:
Only retry when there is an error

Changes in V2:

Added support to the block driver for re-tuning
and retrying after a CRC error. The host driver
is left to decide when an error indicates re-tuning
is needed. The block driver will retry a data request
once if re-tuning is flagged as needed.

SDIO drivers need not be aware of re-tuning because
retrying will anyway cause re-tuning when re-tuning
is flagged as needed. Nevertheless SDIO drivers could
use the need_retune flag to instigate a retry when
otherwise they might not have.

mmc: core: Simplify by adding mmc_execute_tuning()
Dropped because it has been applied

mmc: host: Add facility to support re-tuning
Renamed mmc_retune_retry() to mmc_retune_recheck()
to better reflect what it does.

mmc: core: Move mmc_card_removed() into mmc_start_request()
Dropped because it has been applied

mmc: core: Add support for re-tuning before each request
Fixed un-balanced re-tune hold / release

mmc: sdhci: Always init buf_ready_int
Dropped because it has been applied

mmc: core: Separate out the mmc_switch status check so it can be re-used
New patch

mmc: core: Add support for HS400 re-tuning
It was found that that the original code was not reliable
after a CRC error. The problem was that the CMD13 after a
switch was faiing. So the code was changed to check the
switch status *after* changing the I/O state to match the
switch i.e. the new I/O state is the correct one to use
after a switch.

mmc: sdhci: Flag re-tuning is needed on CRC or End-Bit errors
New patch

mmc: block: Check re-tuning in the recovery path
New patch

mmc: block: Retry data requests when re-tuning is needed
New patch

mmc: core: Don't print reset warning if reset is not supported
New patch

Adrian Hunter (15):
mmc: host: Add facility to support re-tuning
mmc: core: Enable / disable re-tuning
mmc: core: Add support for re-tuning before each request
mmc: core: Check re-tuning before retrying
mmc: core: Hold re-tuning during switch commands
mmc: core: Hold re-tuning during erase commands
mmc: core: Hold re-tuning while bkops ongoing
mmc: mmc: Hold re-tuning if the card is put to sleep
mmc: core: Separate out the mmc_switch status check so it can be re-used
mmc: core: Add support for HS400 re-tuning
mmc: sdhci: Change to new way of doing re-tuning
mmc: sdhci: Flag re-tuning is needed on CRC or End-Bit errors
mmc: block: Check re-tuning in the recovery path
mmc: block: Retry errored data requests when re-tuning is needed
mmc: core: Don't print reset warning if reset is not supported

drivers/mmc/card/block.c | 14 ++++-
drivers/mmc/card/queue.h | 1 +
drivers/mmc/core/core.c | 51 +++++++++++++++---
drivers/mmc/core/core.h | 2 +
drivers/mmc/core/host.c | 85 ++++++++++++++++++++++++++++++
drivers/mmc/core/host.h | 6 +++
drivers/mmc/core/mmc.c | 102 ++++++++++++++++++++++++++++++++++--
drivers/mmc/core/mmc_ops.c | 44 ++++++++++------
drivers/mmc/core/mmc_ops.h | 1 +
drivers/mmc/core/sdio.c | 2 +
drivers/mmc/host/sdhci.c | 126 ++++++++-------------------------------------
drivers/mmc/host/sdhci.h | 3 --
include/linux/mmc/host.h | 28 ++++++++++
13 files changed, 330 insertions(+), 135 deletions(-)

Regards
Adrian