Re: [PATCH V7 00/14] mmc: host: Add facility to support re-tuning

From: Ulf Hansson <ulf.hansson@linaro.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mmc <linux-mmc@vger.kernel.org>,
	Aaron Lu <aaron.lu@intel.com>, Philip Rakity <prakity@nvidia.com>,
	Al Cooper <alcooperx@gmail.com>,
	Arend van Spriel <arend@broadcom.com>
Subject: Re: [PATCH V7 00/14] mmc: host: Add facility to support re-tuning
Date: Fri, 8 May 2015 13:28:47 +0200	[thread overview]
Message-ID: <CAPDyKFrX-Vfi-QpNm+vatXoAMAYiXi9ShWMUujSbHywaQ=Wjfw@mail.gmail.com> (raw)
In-Reply-To: <1430993425-2777-1-git-send-email-adrian.hunter@intel.com>

On 7 May 2015 at 12:10, Adrian Hunter <adrian.hunter@intel.com> wrote:
> Hi
>
> Here is V7 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 V7:
>
>     mmc: host: Add facility to support re-tuning
>         Remove unused mmc_retune_not_needed()
>
>     mmc: core: Enable / disable re-tuning
>         As already sent separately as V7:
>         Also flag re-tune needed in SDIO 'keep_power'
>         case, when a re-tuning timer is being used.
>
>     mmc: core: Add support for re-tuning before each request
>         Fold in next patch
>
>     mmc: core: Check re-tuning before retrying
>         Folded into previous patch
>
>     mmc: mmc: Hold re-tuning if the card is put to sleep
>         Change title to:
>     mmc: mmc: Hold re-tuning in mmc_sleep()
>         Remove changes from V6
>         Hold re-tuning while card is deselected
>
>     mmc: core: Flag re-tuning is needed on CRC errors
>         Do it from core rather than the host
>
> 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 (14):
>       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: 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 in mmc_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: core: Flag re-tuning is needed on CRC 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    |  57 +++++++++++++++++++----
>  drivers/mmc/core/core.h    |   2 +
>  drivers/mmc/core/host.c    |  85 ++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/host.h    |   6 +++
>  drivers/mmc/core/mmc.c     |  98 ++++++++++++++++++++++++++++++++++++++-
>  drivers/mmc/core/mmc_ops.c |  44 +++++++++++-------
>  drivers/mmc/core/mmc_ops.h |   1 +
>  drivers/mmc/core/sdio.c    |   6 ++-
>  drivers/mmc/host/sdhci.c   | 112 ++++++---------------------------------------
>  drivers/mmc/host/sdhci.h   |   3 --
>  include/linux/mmc/host.h   |  23 ++++++++++
>  13 files changed, 322 insertions(+), 130 deletions(-)
>
>
> Regards
> Adrian
>

Adrian, thanks for all your efforts around this patchset. I have now
applied for my next branch.

Kind regards
Uffe