[PATCH V2 00/15] mmc: host: Add facility to support re-tuning

Adrian Hunter
2015-01-29T09:02:25Z

Hi

Here is V2 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, however it is
not strictly necessary because HS400 re-tuning
should only be needed after runtime suspend when
there would not be a conflict.

Nevertheless, this approach has more structure
and potentially more flexibility.

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: Disable re-tuning when card is no longer initialized
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: Comment that callers need to 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 data requests when re-tuning is needed
mmc: core: Don't print reset warning if reset is not supported

drivers/mmc/card/block.c | 19 ++++++-
drivers/mmc/card/queue.h | 1 +
drivers/mmc/core/core.c | 51 ++++++++++++++++--
drivers/mmc/core/core.h | 2 +
drivers/mmc/core/host.c | 63 ++++++++++++++++++++++
drivers/mmc/core/mmc.c | 87 +++++++++++++++++++++++++++++++
drivers/mmc/core/mmc_ops.c | 45 ++++++++++------
drivers/mmc/core/mmc_ops.h | 1 +
drivers/mmc/host/sdhci.c | 127 ++++++++-------------------------------------
include/linux/mmc/host.h | 58 +++++++++++++++++++++
include/linux/mmc/sdhci.h | 3 --
11 files changed, 328 insertions(+), 129 deletions(-)

Regards
Adrian