linux.git/drivers/mmc/core/core.c, branch v5.16

mmc: core: Disable card detect during shutdown

2021-12-20T10:09:15+00:00

It's seems prone to problems by allowing card detect and its corresponding
mmc_rescan() work to run, during platform shutdown. For example, we may end
up turning off the power while initializing a card, which potentially could
damage it.

To avoid this scenario, let's add ->shutdown_pre() callback for the mmc host
class device and then turn of the card detect from there.

Reported-by: Al Cooper 
Suggested-by: Adrian Hunter 
Signed-off-by: Ulf Hansson 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211203141555.105351-1-ulf.hansson@linaro.org

Merge tag 'mmc-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

2021-08-31T21:31:10+00:00

Pull MMC and MEMSTICK updates from Ulf Hansson:
 "MMC core:
   - Return a proper response in case of an ioctl error
   - Issue HPI to interrupt BKOPS for eMMC if it timed out
   - Avoid hogging the CPU while polling for busy
   - Extend sd8787 pwrseq to support the wilc1000 SDIO
   - Remove a couple of confusing warning messages
   - Clarify comment for ->card_busy() host ops

  MMC host:
   - dw_mmc: Add data CRC error injection
   - mmci: De-assert reset during ->probe()
   - rtsx_pci: Fix long reads when clock is pre-scaled
   - sdhci: Correct the tuning command handle for PIO mode
   - sdhci-esdhc-imx: Improve support for auto tuning
   - sdhci-msm: Add support for the sc7280
   - sdhci-of-arasan: Don't auto tune for DDR50 mode for ZynqMP
   - sdhci-of-arasan: Enable support for auto cmd12
   - sdhci-of-arasan: Use 19MHz for SD default speed for ZynqMP for level shifter
   - usdhi6rol0: Implement the ->card_busy() host ops

  MEMSTICK:
   - A couple of minor cleanups"

* tag 'mmc-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (52 commits)
  mmc: queue: Remove unused parameters(request_queue)
  mmc: pwrseq: sd8787: fix compilation warning
  mmc: core: Return correct emmc response in case of ioctl error
  mmc: sdhci-esdhc-imx: Select the correct mode for auto tuning
  mmc: sdhci-esdhc-imx: Remove redundant code for manual tuning
  mmc: core: Issue HPI in case the BKOPS timed out
  mmc: queue: Match the data type of max_segments
  mmc: switch from 'pci_' to 'dma_' API
  memstick: switch from 'pci_' to 'dma_' API
  memstick: r592: Change the name of the 'pci_driver' structure to be consistent
  mmc: pwrseq: add wilc1000_sdio dependency for pwrseq_sd8787
  mmc: pwrseq: sd8787: add support for wilc1000
  dt-bindings: mmc: Extend pwrseq-sd8787 binding for wilc1000
  dt-bindings: mmc: fsl-imx-esdhc: change the pinctrl-names rule
  dt-bindings: mmc: fsl-imx-esdhc: add a new compatible string
  dt-bindings: mmc: renesas,sdhi: Document RZ/G2L bindings
  dt-bindings: mmc: renesas,sdhi: Fix dtbs-check warning
  mmc: core: Update ->card_busy() callback comment
  mmc: usdhi6rol0: Implement card_busy function
  mmc: sdhci: Correct the tuning command handle for PIO mode
  ...

mmc: block: Support alternative_gpt_sector() operation

2021-08-24T16:09:06+00:00

Support generic alternative_gpt_sector() block device operation.
It calculates location of GPT entry for eMMC of NVIDIA Tegra Android
devices. Add new MMC_CAP2_ALT_GPT_TEGRA flag that enables scanning of
alternative GPT sector and add raw_boot_mult field to mmc_ext_csd
which allows to get size of the boot partitions that is needed for
the calculation.

Signed-off-by: Dmitry Osipenko 
Reviewed-by: Ulf Hansson 
Link: https://lore.kernel.org/r/20210820004536.15791-4-digetx@gmail.com
Signed-off-by: Jens Axboe

mmc: core: Only print retune error when we don't check for card removal

2021-08-24T08:15:32+00:00

Skip printing a retune error when we scan for a removed card because we
then expect a failed command.

Signed-off-by: Wolfram Sang 
Acked-by: Adrian Hunter 
Link: https://lore.kernel.org/r/20210630041658.7574-1-wsa+renesas@sang-engineering.com
[Ulf: Rebased patch]
Signed-off-by: Ulf Hansson

mmc: host: factor out clearing the retune state

2021-08-24T08:15:28+00:00

We have this in two places, so let's have a dedicated function. It is
also more readable.

Signed-off-by: Wolfram Sang 
Acked-by: Adrian Hunter 
Reviewed-by: Yoshihiro Shimoda 
Tested-by: Yoshihiro Shimoda 
Link: https://lore.kernel.org/r/20210624151616.38770-4-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson

mmc: core: clear flags before allowing to retune

2021-06-29T14:28:50+00:00

It might be that something goes wrong during tuning so the MMC core will
immediately trigger a retune. In our case it was:

 - we sent a tuning block
 - there was an error so we need to send an abort cmd to the eMMC
 - the abort cmd had a CRC error
 - retune was set by the MMC core

This lead to a vicious circle causing a performance regression of 75%.
So, clear retuning flags before we enable retuning to start with a known
cleared state.

Reported-by Yoshihiro Shimoda 
Suggested-by: Adrian Hunter 
Signed-off-by: Wolfram Sang 
Acked-by: Adrian Hunter 
Reviewed-by: Yoshihiro Shimoda 
Tested-by: Yoshihiro Shimoda 
Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210624151616.38770-2-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson

mmc: core: Extend re-use of __mmc_poll_for_busy()

2021-06-14T11:57:35+00:00

Via __mmc_poll_for_busy() we end up polling with the ->card_busy() host ops
or by sending the CMD13. To allow polling of different types, which is
needed to support a few new SD card features, let's rework the code around
__mmc_poll_for_busy() to make it more generic.

More precisely, let __mmc_poll_for_busy() take a pointer to a callback
function as in-parameter, which it calls to poll for busy state completion.
Additionally, let's share __mmc_poll_for_busy() to allow it to be re-used
outside of mmc_ops.c. Subsequent changes will make use of it.

Signed-off-by: Ulf Hansson 
Reviewed-by: Linus Walleij 
Reviewed-by: Shawn Lin 
Acked-by: Avri Altman 
Link: https://lore.kernel.org/r/20210504161222.101536-5-ulf.hansson@linaro.org

mmc: core: Drop open coding when preparing commands with busy signaling

2021-06-14T11:57:35+00:00

Similar code for validating the host->max_busy_timeout towards the current
command's busy timeout, exists in mmc_do_erase(), mmc_sleep() and
__mmc_switch(). Let's move the common code into a helper function.

Signed-off-by: Ulf Hansson 
Reviewed-by: Linus Walleij 
Reviewed-by: Shawn Lin 
Acked-by: Avri Altman 
Link: https://lore.kernel.org/r/20210504161222.101536-2-ulf.hansson@linaro.org

mmc: core: Fix hanging on I/O during system suspend for removable cards

2021-03-30T09:42:03+00:00

The mmc core uses a PM notifier to temporarily during system suspend, turn
off the card detection mechanism for removal/insertion of (e)MMC/SD/SDIO
cards. Additionally, the notifier may be used to remove an SDIO card
entirely, if a corresponding SDIO functional driver don't have the system
suspend/resume callbacks assigned. This behaviour has been around for a
very long time.

However, a recent bug report tells us there are problems with this
approach. More precisely, when receiving the PM_SUSPEND_PREPARE
notification, we may end up hanging on I/O to be completed, thus also
preventing the system from getting suspended.

In the end what happens, is that the cancel_delayed_work_sync() in
mmc_pm_notify() ends up waiting for mmc_rescan() to complete - and since
mmc_rescan() wants to claim the host, it needs to wait for the I/O to be
completed first.

Typically, this problem is triggered in Android, if there is ongoing I/O
while the user decides to suspend, resume and then suspend the system
again. This due to that after the resume, an mmc_rescan() work gets punted
to the workqueue, which job is to verify that the card remains inserted
after the system has resumed.

To fix this problem, userspace needs to become frozen to suspend the I/O,
prior to turning off the card detection mechanism. Therefore, let's drop
the PM notifiers for mmc subsystem altogether and rely on the card
detection to be turned off/on as a part of the system_freezable_wq, that we
are already using.

Moreover, to allow and SDIO card to be removed during system suspend, let's
manage this from a ->prepare() callback, assigned at the mmc_host_class
level. In this way, we can use the parent device (the mmc_host_class
device), to remove the card device that is the child, in the
device_prepare() phase.

Reported-by: Kiwoong Kim 
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Ulf Hansson 
Reviewed-by: Linus Walleij 
Link: https://lore.kernel.org/r/20210310152900.149380-1-ulf.hansson@linaro.org
Reviewed-by: Kiwoong Kim

mmc: core: Drop reference counting of the bus_ops

2021-03-30T09:41:58+00:00

When the mmc_rescan work is enabled for execution (host->rescan_disable),
it's the only instance per mmc host that is allowed to set/clear the
host->bus_ops pointer.

Besides the mmc_rescan work, there are a couple of scenarios when the
host->bus_ops pointer may be accessed. Typically, those can be described as
as below:

*)
Upper mmc driver layers (like the mmc block device driver or an SDIO
functional driver) needs to execute a host->bus_ops callback. This can be
considered as safe without having to use some special locking mechanism,
because they operate on top of the struct mmc_card. As long as there is a
card to operate upon, the mmc core guarantees that there is a host->bus_ops
assigned as well. Note that, upper layer mmc drivers are of course
responsible to clean up from themselves from their ->remove() callbacks,
otherwise things would fall apart anyways.

**)
Via the mmc host instance, we may need to force a removal of an inserted
mmc card. This happens when a mmc host driver gets unbind, for example. In
this case, we protect the host->bus_ops pointer from concurrent accesses,
by disabling the mmc_rescan work upfront (host->rescan_disable). See
mmc_stop_host() for example.

This said, it seems like the reference counting of the host->bus_ops
pointer at some point have become superfluous. As this is an old mechanism
of the mmc core, it a bit difficult to digest the history of when that
could have happened. However, let's drop the reference counting to avoid
unnecessary code-paths and lockings.

Cc: Pierre Ossman 
Cc: Russell King 
Signed-off-by: Ulf Hansson 
Reviewed-by: Adrian Hunter 
Link: https://lore.kernel.org/r/20210212131610.236843-1-ulf.hansson@linaro.org